Apollo Guidance Computer

578: 1400:. The memory cycle took 12 timing pulses (11.72 μs). The cycle began at timing pulse 1 (TP1) when the AGC loaded the memory address to be fetched into the S register. The memory hardware retrieved the data word from memory at the address specified by the S register. Words from erasable memory were deposited into the G register by timing pulse 6 (TP6); words from fixed memory were available by timing pulse 7. The retrieved memory word was then available in the G register for AGC access during timing pulses 7 through 10. After timing pulse 10, the data in the G register was written back to memory. 1789:. The address spaces were extended by employing the Bank (fixed) and Ebank (erasable) registers, so the only memory of either type that could be addressed at any given time was the current bank, plus the small amount of fixed-fixed memory and the erasable memory. In addition, the bank register could address a maximum of 32 kilowords, so an Sbank (super-bank) register was required to access the last 4 kilowords. All across-bank subroutine calls had to be initiated from fixed-fixed memory through special functions to restore the original bank during the return: essentially a system of 809: 1564: 1833: 586: 4004: 3880: 1641:(matrix × vector) instruction, could be mixed with native AGC code. While the execution time of the pseudo-instructions was increased (due to the need to interpret these instructions at runtime) the interpreter provided many more instructions than AGC natively supported and the memory requirements were much lower than in the case of adding these instructions to the AGC native language which would require additional memory built into the computer (in 821: 350: 1934: 406: 398: 829: 27: 1366: 390: 1694:. The first command module flight was controlled by a software package called CORONA whose development was led by Alex Kosmala. Software for lunar missions consisted of COLOSSUS for the command module, whose development was led by Frederic Martin, and LUMINARY on the lunar module led by George Cherry. Details of these programs were implemented by a team under the direction of 342: 3284: 3280: 1918:

excited by a different source of 800 Hz AC than the one used by the computer as a timing reference. The two 800 Hz sources were frequency locked but not phase locked, and the small random phase variations made it appear as though the antenna was rapidly "dithering" in position, even though

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in such a way as to propagate a carry for multi-precision add/subtract. If the result has no overflow (leftmost 2 bits of A the same), nothing special happens; if there is overflow (those 2 bits differ), the leftmost one goes the memory as the sign bit, register A is changed to +1 or −1 accordingly,

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Block I AGC memory was organized into 1 kiloword banks. The lowest bank (bank 0) was erasable memory (RAM). All banks above bank 0 were fixed memory (ROM). Each AGC instruction had a 12-bit address field. The lower bits (1-10) addressed the memory inside each bank. Bits 11 and 12 selected the bank:

1913:

The problem was not a programming error in the AGC, nor was it pilot error. It was a peripheral hardware design bug that had already been known and documented by Apollo 5 engineers. However, because the problem had only occurred once during testing, they concluded that it was safer to fly with the

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called the 'Waitlist' which scheduled timer-driven 'tasks', controlled the computer. Tasks were short threads of execution which could reschedule themselves for re-execution on the Waitlist, or could kick off a longer operation by starting a 'job' with the Exec. Calculations were carried out using

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The AGC had a 16-bit read bus and a 16-bit write bus. Data from central registers (A, Q, Z, or LP), or other internal registers could be gated onto the read bus with a control signal. The read bus connected to the write bus through a non-inverting buffer, so any data appearing on the read bus also

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In the standby mode, the AGC slept most of the time; therefore it was not awake to perform the Pinc instruction needed to update the AGC's real time clock at 10 ms intervals. To compensate, one of the functions performed by the AGC each time it awoke in the standby mode was to update the real

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were treated as fractions (notional decimal point just to right of the sign bit), so you could produce garbage if the divisor was not larger than the dividend; there was no protection against that situation. In the Block II AGC, a double-precision dividend started in A and L (the Block II LP), and

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The decision to expand the memory and instruction set for Block II, but to retain the Block I's restrictive three-bit op. code and 12-bit address had interesting design consequences. Various tricks were employed to squeeze in additional instructions, such as having special memory addresses which,

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Data transfers worked like this: To move the address of the next instruction from the B register to the S register, an RB (read B) control signal was issued; this caused the address to move from register B to the read bus, and then to the write bus. A WS (write S) control signal moved the address

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switch. This mode turned off the AGC power, except for the 2.048 MHz clock and the scaler. The F17 signal from the scaler turned the AGC power and the AGC back on at 1.28 second intervals. In this mode, the AGC performed essential functions, checked the standby allowed switch, and, if still

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The lower 15 bits of each memory word held AGC instructions or data, with each word being protected by a 16th odd parity bit. This bit was set to 1 or 0 by a parity generator circuit so a count of the 1s in each memory word would always produce an odd number. A parity checking circuit tested the

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During this part of the approach, the processor would normally be almost 85% loaded. The extra 6,400 cycle steals per second added the equivalent of 13% load, leaving just enough time for all scheduled tasks to run to completion. Five minutes into the descent, Buzz Aldrin gave the computer the

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Exchange the contents of memory with the contents of the A register. If the specified memory address is in fixed (read-only) memory, the memory contents are not affected, and this instruction simply loads register A. If it is in erasable memory, overflow "correction" is achieved by storing the

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A Block II version of the AGC was designed in 1966. It retained the basic Block I architecture, but increased erasable memory from 1 to 2 kilowords. Fixed memory was expanded from 24 to 36 kilowords. Instructions were expanded from 11 to 34 and I/O channels were implemented to replace the I/O

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The AGC memory cycle occurred continuously during AGC operation. Instructions needing memory data had to access it during timing pulses 7–10. If the AGC changed the memory word in the G register, the changed word was written back to memory after timing pulse 10. In this way, data words cycled

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Interrupts could be triggered when the counters overflowed. The T3rupt and Dsrupt interrupts were produced when their counters, driven by a 100 Hz hardware clock, overflowed after executing many Pinc subsequences. The Uprupt interrupt was triggered after its counter, executing the Shinc

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because whatever was stored there would emerge shifted or rotated by one bit position, except for one that shifted right seven bit positions, to extract one of the seven-bit interpretive op. codes that were packed two to a word. This was common to Block I and Block II AGCs.

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A set of interrupt-driven user interface routines called 'Pinball' provided keyboard and display services for the jobs and tasks running on the AGC. A set of user-accessible routines were provided to let the astronauts display the contents of various memory locations in

3322:- Manual for CSM and LEM AGC software used on the Apollo 15 mission, including detailed user interface procedures, explanation of many underlying algorithms and limited hardware information. Note that this document has over 500 pages and is over 150 megabytes in size. 1689:

decision capability. When the design requirements for the AGC were defined, necessary software and programming techniques did not exist so they had to be designed from scratch. Many of the trajectory and guidance algorithms used were based on earlier work by

718:, first by five using a ring counter to produce a 102.4 kHz signal. This was then divided by two through 17 successive stages called F1 (51.2 kHz) through F17 (0.78125 Hz). The F10 stage (100 Hz) was fed back into the AGC to increment the 3272: 3266: 1082:

means "decremented but not below zero". Therefore, when the AGC performs the DABS function, positive numbers will head toward plus zero, and so will negative numbers but first revealing their negativity via the four-way skip below. The final step in

1962:

In 2003, an effort was started by Ron Burkey to recover the source code that powered the AGC and build an emulator able to run it, the VirtualAGC. Part of the large amount of source code rescued as a result of this effort was uploaded by a former

1078:(DABS) of the data was then computed and stored in the A register. If the number was greater than zero, the DABS decrements the value by 1; if the number was negative, it is complemented before the decrement is applied—this is the absolute value. 1949:

to demonstrate the practicality of computer driven FBW. The AGC used in the first phase of the program was replaced with another machine in the second phase, and research done on the program led to the development of fly-by-wire systems for the

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The standby mode was designed to reduce power by 5 to 10 W (from 70 W) during midcourse flight when the AGC was not needed. However, in practice, the AGC was left on during all phases of the mission and this feature was never used.

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Astronauts communicated with the AGC using a numeric display and keyboard called the DSKY (for "display and keyboard", pronounced "DIS-kee"). The AGC and its DSKY user interface were developed in the early 1960s for the Apollo program by the

1171:. This method is used to implement arrays and table look-ups; since the addition was done on both whole words, it was also used to modify the op. code in a following (extracode) instruction, and on rare occasions both functions at once. 1150:

when the value being tested was known to be never positive, which occurred more often than one might suppose. That left two whole words unoccupied, and a special committee was responsible for assigning data constants to these

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or decimal in groups of 1, 2, or 3 registers at a time. 'Monitor' routines were provided so the operator could initiate a task to periodically redisplay the contents of certain memory locations. Jobs could be initiated.

1808:, the programmer who requested it). This instruction does not generate an interrupt, rather it performs two actions that are common to interrupt processing. The first action, inhibits further interrupts (and requires a 1698:. Hamilton was very interested in how the astronauts would interact with the software and predicted the types of errors that could occur due to human error. In total, software development on the project comprised 1400 1277:. The fact that overflow is a state rather than an event forgives limited extents of overflow when adding more than two numbers, as long as none of the intermediate totals exceed twice the capacity of a word. 1298:

Multiply the contents of register A by the data at the referenced memory address and store the high-order product in register A and the low-order product in register LP. The parts of the product agree in

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register is loaded with the current value of the program counter (Z). It was only used once in the Apollo software, for setting up the DAP cycle termination sequence in the Digital Autopilot of the

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which did not need a lunar module for its lunar orbit mission. The AGC in the command module was the center of its guidance, navigation and control (GNC) system. The AGC in the lunar module ran its

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Divide the contents of register A by the data at the referenced memory address. Store the quotient in register A and the absolute value of the remainder in register Q. Unlike modern machines,

1357:. The control pulses were the signals which did the actual work of the instruction, such as reading the contents of a register onto the bus, or writing data from the bus into a register. 1914:

existing hardware that they had already tested, than to fly with a newer but largely untested radar system. In the actual hardware, the position of the rendezvous radar was encoded with

1470:. These were memory locations which functioned as up/down counters, or shift registers. The counters would increment, decrement, or shift in response to internal inputs. The increment ( 393:

Photograph of the dual NOR gate chip used to build the Block II Apollo Guidance Computer. Connections (clockwise from top center) ground, inputs (3), output, power, output, inputs (3).

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The Block I AGC initially had 12 kilowords of fixed memory, but this was later increased to 24 kilowords. Block II had 36 kilowords of fixed memory and 2 kilowords of erasable memory.

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According to Kurinec et al, the chips were welded onto the boards rather than soldered as might be expected. Apollo Guidance Computer logic module drawings specify resistance-welding.

1925:'s software and computer design saved the Apollo 11 landing mission. Had it not been for Laning's design, the landing would have been aborted for lack of a stable guidance computer. 484:, the later Block II version (used in the crewed flights) used about 2,800 ICs, mostly dual three-input NOR gates and smaller numbers of expanders and sense amplifiers. The ICs, from 380:) of the lunar module, to be used in the event of failure of the LM PGNCS. The AGS could be used to take off from the Moon, and to rendezvous with the command module, but not to land. 345:

The display and keyboard (DSKY) interface of the Apollo Guidance Computer mounted on the control panel of the command module, with the flight director attitude indicator (FDAI) above

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with more complex and capable pseudo-instructions than the native AGC. These instructions simplified the navigational programs. Interpreted code, which featured double precision

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The AGC responded to each interrupt by temporarily suspending the current program, executing a short interrupt service routine, and then resuming the interrupted program.

1586:. The bulk of the software was on read-only rope memory and thus could not be changed in operation, but some key parts of the software were stored in standard read-write 3403: 1642: 1334:. Simple instructions, such as TC, executed in a single subsequence of 12 pulses. More complex instructions required several subsequences. The multiply instruction ( 1678: 5066: 3025: 240:(LM). The AGC provided computation and electronic interfaces for guidance, navigation, and control of the spacecraft. The AGC was the first computer based on 1703: 1682: 1062:

A complex conditional branch instruction. The A register was loaded with data retrieved from the address specified by the instruction. (Because the AGC uses

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on July 7, 2016, attracting significant media attention. The original Apollo 11 Guidance Computer source code was originally made accessible in 2003 by the

2043:(calculate and display DELTAH, once) would have only added approximately 5% load to the system, and would have only done so once, when ENTER was pressed. 1821: 3260: 1878:, which instructed it to periodically calculate and display DELTAH (the difference between altitude sensed by the radar and the computed altitude). The 2359: 2095: 1954:. The AGC also led, albeit indirectly, to the development of fly-by-wire systems for the generation of fighters that were being developed at the time. 1870:

from the rendezvous radar (tracking the orbiting command module), intentionally left on standby during the descent in case it was needed for an abort.

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Add the contents of memory to register A and store the result in A. The 2 leftmost bits of A may be different (overflow state) before and/or after the

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The command module has two DSKYs connected to its AGC: one located on the main instrument panel and a second located in the lower equipment bay near a

3440: 1127:. The absolute value function was deemed important enough to be built into this instruction; when used for only this purpose, the sequence after the 3012: 1866:("Executive overflow - NO VAC AREAS"). The response of the AGC to either alarm was a soft restart. The cause was a rapid, steady stream of spurious 4038: 1378:

00 selected the erasable memory bank; 01 selected the lowest bank (bank 1) of fixed memory; 10 selected the next one (bank 2); and 11 selected the

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which the AGC used to perform internal operations. The 1.024 MHz clock was also divided by two to produce a 512 kHz signal called the

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and other involuntary counters using Pinc (discussed below). The F17 stage was used to intermittently run the AGC when it was operating in the

4879: 3718: 2016: 865:(super-bank): 1-bit extension to Fbank, required because the last 4 kilowords of the 36-kiloword ROM was not reachable using Fbank alone 4157: 3914: 3348: 1898:

up". The AGC software had been designed with priority scheduling, and automatically recovered, deleting lower priority tasks including the

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An unconditional branch to the address specified by the instruction. The return address was automatically stored in the Q register, so the

5036: 4602: 4419: 1805: 1622:, but display readouts were in units of feet, feet per second, and nautical miles – units that the Apollo astronauts were accustomed to. 3228: 2264: 2198: 925:: General-purpose buffer register, also used to pre-fetch the next instruction. At the start of the next instruction, the upper bits of 5999: 5390: 2598: 1979:. It was transcribed and digitalized from the original hard-copy source code listings that were made in the '60s. In mid-2016, former 507:

The use of a single type of IC (the dual NOR3) throughout the AGC avoided problems that plagued another early IC computer design, the

4382: 314:, but computers flew most of Project Apollo except briefly during lunar landings. Each Moon flight carried two AGCs, one each in the 2693: 5031: 3723: 3698: 1720:

The Apollo Guidance computer has been called "The fourth astronaut" for its role in helping the three astronauts who relied on it:

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parity bit during each memory cycle; if the bit didn't match the expected value, the memory word was assumed to be corrupted and a

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DSKY, IMU, Hand Controller, Rendezvous Radar (CM), Landing Radar (LM), Telemetry Receiver, Engine Command, Reaction Control System

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Subtract (ones' complement) the data at the referenced memory address from the contents of register A and store the result in A.

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to fixed memory) to complete the formation of the carry (+1, 0, or −1) into the next higher-precision word. Angles were kept in

5385: 4856: 3786: 3064: 2289: 353:

Partial list of numeric codes for verbs and nouns in the Apollo Guidance Computer, printed for quick reference on a side panel

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the correctly signed remainder was delivered in L. That considerably simplified the subroutine for double precision division.

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Several registers could be read onto the read bus simultaneously. When this occurred, data from each register was inclusive-

5800: 4924: 4187: 4031: 3770: 3713: 3708: 2468: 2151: 1741:

registers on Block I. The Block II version is the one that actually flew to the moon. Block I was used during the uncrewed

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memory, because they were always available, regardless of the contents of the Bank register. Banks 3 and above were called

3292:– An AGC system programmer discusses some obscure details of the development of AGC, including specifics of Ed's Interrupt 3125:"GitHub - chrislgarry/Apollo-11: Original Apollo 11 Guidance Computer (AGC) source code for the command and lunar modules" 5984: 5810: 4951: 3686: 2358:

Butrica, Andrew J. (2015). "Chapter 3: NASA's Role in the Manufacture of Integrated Circuits". In Dick, Steven J. (ed.).

2318: 443: 2333:"Apollo Requirements for Process Control and Fabrication of Resistance-Welded Electronic Circuit Modules and Assemblies" 4078: 3740: 3325: 2774: 1187:

25). This is the instruction used to return from interrupts. It causes execution to resume at the interrupted location.

577: 470: 3051: 2997: 2795: 2735: 5118: 4946: 4919: 4298: 3693: 3297:

Documentation of AGC hardware design, and particularly the use of the new integrated circuits in place of transistors

2103: 473:(IMP) in 1963, IC technology was later adopted for the AGC. The Apollo flight computer was the first computer to use 5974: 5933: 5496: 4389: 4355: 4350: 4269: 4234: 3907: 3883: 3426: 3357:– Ronald Burkey's AGC simulator, plus source and binary code recovery for the Colossus (CSM) and Luminary (LEM) SW. 545:. Both had cycle times of 11.72 microseconds. The memory word length was 16 bits: 15 bits of data and one odd- 3347:– John Pultorak's successful project to build a hardware replica of the Block I AGC in his basement. Mirror site: 5994: 5908: 5805: 5206: 5113: 4914: 4135: 4024: 3986: 3511: 2584: 1645:

memory was very expensive). The average pseudo-instruction required about 24 ms to execute. The assembler, named

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alarm occurred. When reporting the second alarm, Aldrin added the comment "It appears to come up when we have a

1111:. The primary purpose of the count was to allow an ordinary loop, controlled by a positive counter, to end in a 4934: 4653: 4088: 3801: 3681: 3651: 1666: 1626: 423: 295: 5108: 4956: 4929: 4790: 4404: 4365: 4222: 3791: 3760: 3735: 2397: 1695: 1087:

is a four-way skip, depending upon the data in register A before the DABS. If register A was greater than 0,

668: 664: 489: 123: 2510: 5545: 5307: 4783: 4744: 4399: 4394: 4328: 4140: 3935: 3860: 3580: 3148: 267: 2136: 1197:

leftmost of the 16 bits in A as the sign bit in memory, but there is no exceptional behavior like that of

859:: 3-bit RAM bank register, to select the 256-word RAM bank when addressing in the erasable-switchable mode 5969: 5172: 4869: 4567: 4264: 4007: 3900: 3839: 3671: 3026:"The code that took America to the moon was just published to GitHub, and it's like a 1960s time capsule" 1729: 2174: 2119: 1330:. The timing pulses were named TP1 through TP12. Each set of 12 timing pulses was called an instruction 5822: 5469: 4886: 4377: 4345: 4115: 4103: 4083: 3806: 3750: 3307: 2945:"NASA SP-2000-4224 — Computers Take Flight: A History of NASA's Pioneering Digital Fly-By-Wire Project" 2460:

Peirce, C. S. (manuscript winter of 1880–81), "A Boolian Algebra with One Constant", published 1933 in

1598: 774: 683: 633: 515: 2898: 2820: 6004: 5913: 5876: 5866: 4254: 3755: 3703: 3615: 2944: 1482:) was handled by one subsequence of microinstructions inserted between any two regular instructions. 1516:

appeared on the write bus. Other control signals could copy write bus data back into the registers.

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to the no-overflow logic; when it is a normal possibility (as in multi-precision add/subtract), the

686:(FDAI), controlled by the AGC, was located above the DSKY on the commander's console and on the LM. 5928: 5271: 5248: 5098: 5060: 4896: 4846: 4841: 4318: 4212: 4120: 3945: 3745: 3620: 3585: 3506: 3254: 3242: 2011: 1606: 1919:

it was completely stationary. These phantom movements generated the rapid series of cycle steals.

210:

24 in × 12.5 in × 6.5 in (61 cm × 32 cm × 17 cm)

5881: 5664: 5558: 5522: 5439: 5423: 5265: 5054: 5013: 5001: 4864: 4778: 4699: 4464: 4125: 4068: 3728: 3641: 3538: 3216: 2402: 1210:

Load register A with the ones' complement of the data referenced by the specified memory address.

813: 750: 550: 485: 2917: 2473: 5687: 5659: 5569: 5534: 5283: 5277: 5259: 4993: 4987: 4891: 4795: 4686: 4625: 4487: 4130: 3605: 2654: 2063: 1309: 1066:

notation, there are two representations of zero. When all bits are set to zero, this is called

493: 409: 5861: 5770: 5516: 5228: 5046: 4805: 4773: 4731: 4643: 4444: 4259: 4249: 4239: 4229: 4199: 4182: 4047: 3546: 3532: 2006: 636: 523: 435: 373: 315: 233: 3248: 3177: 2039:(in this case, 68, DELTAH) approximately twice per second. Had Aldrin known this, a simple 1159:

Add the data retrieved at the address specified by the instruction to the next instruction.

5891: 5827: 5413: 5135: 5025: 4972: 4504: 4217: 4073: 4055: 3855: 3765: 3676: 1674: 1670: 1587: 1396:

The AGC transferred data to and from memory through the G register in a process called the

535: 427: 153: 149: 3236: 3052:"Original Apollo 11 Guidance Computer (AGC) source code for the command and lunar modules" 2552: 8: 5938: 5923: 5743: 5594: 5576: 5540: 5528: 5182: 5129: 4906: 4822: 4704: 4559: 4454: 4313: 3827: 3796: 3551: 3527: 3334:

Original Apollo 11 Guidance Computer (AGC) source code for the command and lunar modules.

3213:– The infamous memo that served as de facto official documentation of the instruction set 2697: 1544: 1224: 1063: 908: 888: 702: 566: 558: 319: 237: 5795: 5787: 5639: 5614: 5418: 5293: 4817: 4758: 4638: 4370: 4098: 3557: 1922: 1902:

display task, to complete its critical guidance and control tasks. Guidance controller

1841: 1602: 836:

The AGC had additional registers that were used internally in the course of operation:

735: 695: 643:, limiting the update rate. Three five-digit signed numbers could also be displayed in 466: 439: 415: 244: 119: 2222: 5748: 5715: 5631: 5563: 5464: 5454: 5444: 5375: 5370: 5365: 5288: 5217: 5123: 5083: 4716: 4666: 4616: 4592: 4474: 4414: 4409: 4291: 4207: 3302: 3183: 2770: 2741: 2720: 2622: 2489: 2372: 2099: 1686: 1579: 1467: 808: 679: 656: 652: 1590:

and could be overwritten by the astronauts using the DSKY interface, as was done on

5918: 5851: 5837: 5692: 5599: 5553: 5360: 5355: 5350: 5345: 5340: 5330: 5200: 5167: 5078: 5073: 4982: 4834: 4829: 4812: 4800: 4739: 4303: 4281: 4167: 4145: 4063: 3833: 3625: 3610: 2845: 1855: 1781:). Other instructions were implemented by preceding them with a special version of 1370: 1261: 1257: 542: 539: 508: 279: 275: 225: 164: 160: 3328:

for Command Module code (Comanche054) and Lunar Module code (Luminary099) as text.

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334:(primary guidance, navigation and control system), with the acronym pronounced as 5832: 5817: 5765: 5669: 5644: 5481: 5474: 5325: 5320: 5315: 5254: 5162: 5152: 4874: 4709: 4661: 4424: 4308: 4276: 4177: 4172: 4093: 3971: 3950: 3319: 1630: 1450: 969: 760: 719: 2892: 2890: 2290:"Recreating History: Making the Chip that went on the Moon in 1969 on Apollo 11" 2159: 1570:

standing next to listings of the software she and her MIT team produced for the

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enabled, turned off the power and went back to sleep until the next F17 signal.

1024:, were directly accessed by the 3-bit op. code. The final three were denoted as 629:

specified which data were affected by the action specified by the Verb command.

5943: 5777: 5760: 5753: 5649: 5506: 5243: 5157: 5088: 4671: 4633: 4582: 4577: 4572: 4286: 4110: 3501: 3496: 3449: 2762: 2636: 2436:

MIT's Role in Project Apollo: Final report on contracts NAS 9-163 and NAS 94065

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of effort, with a peak workforce of 350 people. In 2016, Hamilton received the

1691: 1571: 594: 526:

from which any other gate can be made, though at the cost of using more gates.

480:

While the Block I version used 4,100 ICs, each containing a single three-input

447: 307: 229: 3409: 3385: 3372: 1882:

added another 10% to the processor workload, causing executive overflow and a

5963: 5738: 5654: 4694: 4676: 4469: 4162: 3463: 2887: 2087: 1951: 1832: 1714: 1619: 1459:

was generated each time a 16-bit word of uplink data was loaded into the AGC.

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was generated at regular intervals from a hardware timer to update the AGC's

877:: 16-bit memory buffer register, to hold data words moving to and from memory 714: 632:

Each digit was displayed via a green (specified as 530 nm) high-voltage

450:, Ramon Alonso, and Hugh Blair-Smith. The flight hardware was fabricated by 431: 311: 283: 260: 248: 4597: 3369:

Shareware Lunar Lander Simulator with a working AGC and DSKY (Windows only).

3331: 3059: 2712: 5948: 5886: 5702: 5679: 5491: 5212: 4150: 3822: 3600: 3354: 3124: 3007: 1996: 1946: 1851: 1817: 1699: 1634: 1543:

through the bus and could complement (invert) data through the C register,

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Kurinec, Santosh K; Indovina, Mark; McNulty, Karl; Seitz, Matthew (2021).

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continuously from memory to the G register and then back again to memory.

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There were also four locations in core memory, at addresses 20–23, dubbed

709:; this signal was used to synchronize external Apollo spacecraft systems. 613:-style keyboard. Commands were entered numerically, as two-digit numbers: 5733: 5697: 5408: 5380: 5238: 5093: 4016: 3866: 3397: 2137:"How did the Apollo flight computers get men to the moon and back ?" 1942: 1937:

Fly By Wire testbed aircraft. The AGC DSKY is visible in the avionics bay

1907: 1903: 1837: 1790: 1725: 1583: 1551:. This was accomplished by inverting both operands, performing a logical 843:: 12-bit memory address register, the lower portion of the memory address 519: 287: 3360: 1531:

feature was used to implement the Mask instruction, which was a logical

585: 5619: 5609: 5604: 5586: 5486: 5459: 4721: 4554: 4524: 4244: 3955: 3646: 3100: 2321:. MIT Instrumentation Lab. July 11, 1963. p. Sheet 1 of 2, Note 2. 1976: 1972: 1120: 698: 610: 546: 271: 247:. The computer's performance was comparable to the first generation of 3344: 1820:. It is believed to be responsible for problems emulating the LEM AGC 1757:

when referenced, would implement a certain function. For instance, an

5710: 5707: 5449: 4519: 4497: 3892: 3473: 1677:—particularly for the design of more reliable systems that relied on 1610: 1591: 1431:

was triggered at regular intervals to update the user display (DSKY).

1421: 820: 497: 349: 1625:

The AGC had a sophisticated software interpreter, developed by the

5725: 4544: 3478: 3468: 2761:

Collins, Michael; Aldrin, Edwin (1975), Cortright, Edgar M. (ed.),

1750: 1746: 1742: 1653:, enforced proper transitions between native and interpreted code. 1486:

subsequence, had shifted 16 bits of uplink data into the AGC.

850: 562: 481: 451: 366: 327: 323: 252: 99: 50: 3404:

Restorers try to get lunar module guidance computer up and running

2972: 2553:"The History of Apollo On-board Guidance, Navigation, and Control" 1346:

subsequence which was repeated 6 times, and then terminated by an

4534: 4492: 2494: 1915: 1535:

operation. Because the AGC had no native ability to do a logical

675: 660: 648: 474: 412: 241: 116: 3366: 2694:"NASA Engineers and Scientists-Transforming Dreams Into Reality" 2092:

Journey to the Moon: The History of the Apollo Guidance Computer

4549: 4514: 4479: 3976: 3002: 2002: 1984: 1968: 1886:

alarm. After being given the "GO" from Houston, Aldrin entered

1710: 1709:

The Apollo Guidance Computer software influenced the design of

1390:

because the selected bank was determined by the bank register.

973: 554: 256: 2655:"Her Code Got Humans on the Moon—And Invented Software Itself" 1933: 1103:. Less than zero causes a skip to the third instruction after 5007: 4539: 4509: 3981: 2998:"AGC source code collection on Github, maintained by iBiblio" 2227:

Ramón Alonso, el argentino que llevó a la Apollo 11 a la Luna

1812:

instruction to enable them again). In the second action, the

1658: 1350:

subsequence. This was reduced to 3 subsequences in Block II.

1289:

of memory with register A and store the result in register A.

671:. This calculator-style interface was the first of its kind. 644: 640: 609:

It has an array of indicator lights, numeric displays, and a

511: 501: 1326:

Instructions were implemented in groups of 12 steps, called

828: 682:

platform. The lunar module had a single DSKY for its AGC. A

405: 397: 5871: 5019: 4939: 4529: 3595: 2603:

AGC History Project (Caltech archive, original site closed)

2527: 2368: 2287: 2269:

AGC History Project (Caltech archive, original site closed)

2245:

AGC History Project (Caltech archive, original site closed)

2203:

AGC History Project (Caltech archive, original site closed)

2120:"Apollo Guidance, Navigation and Control Hardware Overview" 1980: 1964: 1365: 1028:

because they were accessed by performing a special type of

943:: Not a separate register, but the ones' complement of the 618: 614: 389: 26: 3250:

Lunar Module Attitude Controller Assembly Input Processing

2035:

More specifically, verb 16 instructs the AGC to print the

1910:

issued several "GO" calls and the landing was successful.

1232:. Whenever overflow is a possible but abnormal event, the 1228:

and control skips to the second instruction following the

907:: Not really a register, but the output of the adder (the 16:

Guidance and navigation computer used in Apollo spacecraft

4459: 4449: 3391: 2567: 2565: 1353:

Each timing pulse in a subsequence could trigger up to 5

1167:

specified by the operand of the instruction that follows

1039:

The Block I AGC instructions consisted of the following:

274:. Most of the software on the AGC is stored in a special 2905:, Breckenridge, Colorado: American Astronautical Society 2737:

The Apollo Guidance Computer: Architecture and Operation

2713:"13 minutes to the moon: Episode 5 The fourth astronaut" 2361:

Historical Studies in the Societal Impact of Spaceflight

1637:, scalar and vector arithmetic (16 and 24-bit), even an 976:, and 12 bits for address. Block I had 11 instructions: 454:, whose Herb Thaler was also on the architectural team. 1605:

consisting of the 'Exec', a batch job-scheduling using

1143:

ONE. A curious side effect was the creation and use of

1107:, and minus zero skips to the fourth instruction after 341: 2562: 2393:"Apollo Guidance Computer and the First Silicon Chips" 1415: 1983:

intern Chris Garry uploaded the AGC Source code onto

1437:

was generated by various hardware failures or alarms.

1163:

can be used to add or subtract an index value to the

891:

arithmetic) or the increment to the program counter (

853:

ROM bank when addressing in the fixed-switchable mode

763:– the address of the next instruction to be executed 694:

The AGC timing reference came from a 2.048 MHz

3308:

Integrated Circuits in the Apollo Guidance Computer

3275:, for Command Module guidance computer. (nb. 83 Mb) 2844:Martin, Fred H. (July 1994), Jones, Eric M. (ed.), 2215: 1999:- the Apollo Primary Guidance and Navigation System 1765:instruction to return from an interrupt. Likewise, 712:The master frequency was further divided through a 3269:, for Lunar Module guidance computer. (nb. 622 Mb) 3077:"Archiving and referencing the Apollo source code" 2065:Programmer's Manual, Block 2 AGC Assembly Language 1862:("Executive overflow - NO CORE SETS"), and then a 1547:was used to implement the equivalent of a logical 1219:Store register A at the specified memory address. 933:, and the lower bits (the address) were copied to 871:: 4-bit sequence register; the current instruction 816:. The AGC is opened up, showing its logic modules. 3363:– A web-based AGC simulator based on Virtual AGC. 1717:and early fly-by-wire fighter aircraft systems. 1091:skips to the first instruction immediately after 625:described the type of action to be performed and 357:Each lunar mission had two additional computers: 5961: 3601:Primary guidance, navigation, and control system 3257:) – By José Portillo Lugo, History of Technology 3179:Digital Apollo: Human and Machine in Spaceflight 2681:. NASA Office of Logic Design. February 3, 2010. 2149: 1555:through the bus, and then inverting the result. 1494:The AGC had a power-saving mode controlled by a 849:: 4-bit ROM bank register, to select the 1 282:, fashioned by weaving wires through and around 3290:Annotations to Eldon Hall's Journey to the Moon 2899:"Tales From The Lunar Module Guidance Computer" 2769:, Washington, DC: NASA, pp. Chapter 11.4, 2511:"Scene at MIT: Margaret Hamilton's Apollo code" 2428: 2426: 2424: 2422: 2420: 1827: 1665:The design principles developed for the AGC by 1119:to the beginning of the loop, equivalent to an 1053:instruction could be used for subroutine calls. 1928: 1706:for her role in creating the flight software. 1443:signaled a key press from the user's keyboard. 929:(containing the next op. code) were copied to 4032: 3908: 3719:Charged Particle Lunar Environment Experiment 3434: 3218:Computers in Spaceflight: The NASA Experience 2760: 2502: 2156:Computers in Spaceflight: The NASA Experience 1338:) used 8 subsequences: an initial one called 1070:. If all bits are set to one, this is called 418:welded to PCB in the Apollo guidance computer 3245:) – By David Scott, Apollo mission astronaut 3203:Documentation on the AGC and its development 2417: 2117: 1941:The AGC formed the basis of an experimental 701:. The clock was divided by two to produce a 5037:Computer performance by orders of magnitude 3448: 3281:National Air and Space Museum's AGC Block I 3238:The Apollo Guidance Computer - A Users View 3182:. Cambridge, Massachusetts: The MIT Press. 2903:27th annual Guidance and Control Conference 2819:Adler, Peter (1998), Jones, Eric M. (ed.), 2767:NASA SP-350, Apollo Expeditions to the Moon 2733: 2490:"Apollo DSKY panel relight: The full story" 2477:The Existential Graphs of Charles S. Peirce 2311: 2082: 2080: 500:, and the wiring was then embedded in cast 4046: 4039: 4025: 3915: 3901: 3441: 3427: 3149:"Apollo 11's source code is now on GitHub" 2653:Harvey IV, Harry Gould (13 October 2015). 2466:v. 4, paragraphs 12–20. Reprinted 1989 in 2005:(IBM S/360-derived) computers used in the 1800:instruction (the name is a contraction of 812:DSKY and AGC prototypes on display at the 738:for general computational use, called the 663:). Although data was stored internally in 25: 2868: 2740:. Springer Science & Business Media. 2652: 2587:. UK Metric Association. 18 October 2018. 2508: 2325: 2166: 832:Block II logic module, with flat-pack ICs 639:; these were driven by electromechanical 534:The computer had 2,048 words of erasable 3699:Apollo Lunar Surface Experiments Package 2924:. San Francisco: Condé Nast Publications 2152:"The Apollo guidance computer: Hardware" 2077: 1932: 1854:generated unanticipated warnings during 1831: 1773:instruction (inhibit interrupts), while 1749:flights, and was on board the ill-fated 1562: 1520:from the write bus into the S register. 1364: 827: 819: 807: 584: 581:Apollo computer DSKY user interface unit 576: 404: 396: 388: 348: 340: 3314:Documentation of AGC software operation 3221:– By James Tomayko (Chapter 2, Part 5, 3175: 3023: 2942: 2691: 2615: 2571: 2546: 2544: 2542: 2533: 2357: 1264:, and elapsed time in triple precision. 824:Prototype logic module from Block I AGC 5980:Computer-related introductions in 1966 5962: 3922: 3724:Lunar Ejecta and Meteorites Experiment 3339:Some AGC-based projects and simulators 3263:– With comprehensive document archive 3223:The Apollo guidance computer: Hardware 2843: 2577: 2191: 2118:Interbartolo, Michael (January 2009). 1957: 1099:skips to the second instruction after 1036:) immediately before the instruction. 286:, though a small amount of read/write 5990:Massachusetts Institute of Technology 4020: 3896: 3422: 3273:Colossus software source code listing 3267:Luminary software source code listing 2896: 2818: 2671: 2648: 2646: 1095:. If register A contained plus zero, 651:, and were typically used to display 557:word format was 14 bits of data, one 326:which was an Earth orbit mission and 5008:Floating-point operations per second 3771:Suprathermal Ion Detector Experiment 3714:Apollo 14 Passive Seismic Experiment 3709:Apollo 12 Passive Seismic Experiment 2915: 2710: 2685: 2550: 2539: 2432: 2223:"Ramon Alonso's interview (Spanish)" 2172: 2086: 901:: The other ('y') input to the adder 729: 3210:AGC4 Memo #9, Block II Instructions 2918:"Apollo 11: Mission Out of Control" 2625:(Press release). September 3, 2003. 1906:and his support team that included 1416:Interrupts and involuntary counters 887:(the adder was used to perform all 401:AGC dual 3-input NOR gate schematic 13: 3741:Lunar Seismic Profiling Experiment 3729:Solar Wind Spectrometer Experiment 2970: 2643: 2558:. Charles Stark Draper Laboratory. 2319:"LOGIC MODULE ASSEMBLY NO. A1-A16" 963: 803: 684:flight director attitude indicator 471:Interplanetary Monitoring Platform 270:length, with 15 data bits and one 14: 6016: 6000:Spacecraft navigation instruments 3694:Solar Wind Composition Experiment 3197: 3049: 2869:Cortright, Edgar M., ed. (1975), 2846:"Apollo 11 : 25 Years Later" 2599:"Hugh Blair-Smith's Introduction" 2297:Rochester Institute of Technology 2229:, Diario La Nacion, March 7, 2010 1020:(extra). The first eight, called 911:sum of the contents of registers 572: 460: 251:from the late 1970s, such as the 232:that was installed on board each 31:Apollo Guidance Computer and DSKY 5934:Semiconductor device fabrication 4003: 4002: 3884:Category:Apollo program hardware 3879: 3878: 1578:AGC software was written in AGC 1527:ed onto the bus. This inclusive- 1466:The AGC also had 20 involuntary 1223:also detects, and corrects for, 145:15-bit wordlength + 1-bit parity 5909:History of general-purpose CPUs 4136:Nondeterministic Turing machine 3992:Universal Space Guidance System 3987:Launch Vehicle Digital Computer 3512:Launch Vehicle Digital Computer 3303:AGC Integrated Circuit Packages 3141: 3117: 3093: 3069: 3043: 3017: 2990: 2964: 2936: 2916:Witt, Stephen (June 24, 2019). 2909: 2897:Eyles, Don (February 6, 2004), 2875:Apollo 11 Lunar Surface Journal 2862: 2850:Apollo 11 Lunar Surface Journal 2837: 2825:Apollo 11 Lunar Surface Journal 2812: 2788: 2754: 2727: 2704: 2629: 2591: 2482: 2454: 2385: 2351: 2281: 2257: 2029: 1489: 703:four-phase 1.024 MHz clock 659:or a required velocity change ( 363:Launch Vehicle Digital Computer 41:Charles Stark Draper Laboratory 4089:Deterministic finite automaton 3802:Lunar Landing Research Vehicle 3682:Lunar Laser Ranging experiment 3652:Thermal Micrometeoroid Garment 3024:Collins, Keith (9 July 2016). 2551:Hoag, David (September 1976). 2509:Weinstock, Maia (2016-08-17). 2475:. See Roberts, Don D. (2009), 2233: 2143: 2129: 2111: 2056: 1796:The Block II AGC also has the 1667:MIT Instrumentation Laboratory 1627:MIT Instrumentation Laboratory 1260:, distances and velocities in 959:: Five 16-bit output registers 430:, with hardware design led by 424:MIT Instrumentation Laboratory 296:MIT Instrumentation Laboratory 1: 4880:Simultaneous and heterogenous 3761:Cold Cathode Gauge Experiment 3736:Modular Equipment Transporter 2734:O'Brien, Frank (2010-06-25). 2623:"NASA Honors Apollo Engineer" 2469:Writings of Charles S. Peirce 2398:National Air and Space Museum 2199:"Ramon Alonso's introduction" 2173:Agle, D.C. (September 1998). 2050: 1704:Presidential Medal of Freedom 1510: 1412:panel light was illuminated. 1285:Perform a bit-wise (boolean) 953:: Four 16-bit input registers 669:United States customary units 5564:Integrated memory controller 5546:Translation lookaside buffer 4745:Memory dependence prediction 4188:Random-access stored program 4141:Probabilistic Turing machine 3936:Apollo Abort Guidance System 3861:Rendezvous Docking Simulator 3672:Portable Life Support System 3581:Apollo Abort Guidance System 3373:AGC restarted 45 years later 3320:Delco Electronics, Apollo 15 2241:"Hugh Blair-Smith biography" 2017:History of computer hardware 1828:1201 and 1202 program alarms 1761:to address 25 triggered the 1669:, directed in late 1960s by 1503:time clock by 1.28 seconds. 422:The AGC was designed at the 369:booster instrumentation ring 301: 7: 5020:Synaptic updates per second 4008:Category:Guidance computers 3840:Apollo 11 goodwill messages 3398:Weaving the way to the Moon 3332:GitHub Complete Source Code 2871:"The Lunar Module Computer" 2637:"Virtual AGC Luminary Page" 1990: 1929:Applications outside Apollo 1735: 1558: 1360: 80:; 49 years ago 62:; 58 years ago 10: 6021: 5985:Assembly language software 5424:Heterogeneous architecture 4346:Orthogonal instruction set 4116:Alternating Turing machine 4104:Quantum cellular automaton 3807:Mobile quarantine facility 3751:Lunar Surface Magnetometer 3394:Science Reporter – youtube 3176:Mindell, David A. (2008). 3169: 2943:Tomayko, James E. (2000), 2821:"Apollo 11 Program Alarms" 2265:"Herb Thaler introduction" 1599:real-time operating system 1420:The AGC had five vectored 1059:(count, compare, and skip) 787:: The lower product after 496:. They were connected via 5914:Microprocessor chronology 5901: 5877:Dynamic frequency scaling 5850: 5786: 5724: 5678: 5630: 5585: 5505: 5432: 5401: 5306: 5227: 5191: 5145: 5045: 5032:Cache performance metrics 4971: 4905: 4855: 4766: 4757: 4730: 4685: 4652: 4624: 4615: 4435: 4338: 4327: 4198: 4054: 4000: 3964: 3928: 3876: 3848: 3815: 3779: 3756:Lunar Traverse Gravimeter 3704:Active Seismic Experiment 3662: 3634: 3616:Descent propulsion system 3571: 3520: 3487: 3456: 2679:"About Margaret Hamilton" 2472:v. 4, pp. 218–21, Google 2150:James E. Tomayko (1988). 2094:, Reston, Virginia, USA: 1945:system installed into an 1858:, with the AGC showing a 1856:Apollo 11's lunar descent 1673:, became foundational to 1607:cooperative multi-tasking 1539:, but could do a logical 1076:diminished absolute value 769:: The remainder from the 753:, for general computation 689: 667:, they were displayed as 589:LM DSKY interface diagram 529: 490:resistor–transistor logic 488:, were implemented using 384: 306:Astronauts manually flew 206: 198: 190: 182: 174: 138: 130: 111: 92: 74: 56: 46: 36: 24: 5929:Hardware security module 5272:Digital signal processor 5249:Graphics processing unit 5061:Graphics processing unit 3946:Gemini Guidance Computer 3941:Apollo Guidance Computer 3746:Lunar Surface Gravimeter 3621:Ascent propulsion system 3596:Lunar Sounder Experiment 3591:Apollo Guidance Computer 3586:Apollo Docking Mechanism 3081:www.softwareheritage.org 2954:, Washington, D.C.: NASA 2763:"A Yellow Caution Light" 2271:, MIT, 14 September 2001 2022: 2012:Gemini Guidance Computer 734:The AGC had four 16-bit 322:, with the exception of 298:and first flew in 1966. 218:Apollo Guidance Computer 20:Apollo Guidance Computer 5975:Apollo program hardware 5882:Dynamic voltage scaling 5665:Memory address register 5559:Branch target predictor 5523:Address generation unit 5266:Physics processing unit 5055:Central processing unit 5014:Transactions per second 5002:Instructions per second 4925:Array processing (SIMT) 4069:Stored-program computer 3687:list of retroreflectors 3450:Apollo program hardware 3101:"Virtual AGC Home Page" 2952:The NASA History Series 2796:"chrislgarry/Apollo-11" 2605:, MIT, 30 November 2001 2433:Hall, Eldon C. (1972). 2403:Smithsonian Institution 1649:for an early prototype 883:: The 'x' input to the 814:Computer History Museum 605:and usually pronounced 486:Fairchild Semiconductor 202:70 lb (32 kg) 5995:1975 disestablishments 5688:Hardwired control unit 5570:Memory management unit 5535:Memory management unit 5284:Secure cryptoprocessor 5278:Tensor Processing Unit 5260:Vision processing unit 4994:Cycles per instruction 4988:Instructions per cycle 4935:Associative processing 4626:Instruction pipelining 4048:Processor technologies 3792:Launch Umbilical Tower 3606:Apollo Telescope Mount 2175:"Flying the Gusmobile" 2158:. NASA. Archived from 1938: 1848: 1575: 1374: 1179:A special instance of 1026:extracode instructions 833: 825: 817: 678:used for aligning the 590: 582: 516:diode–transistor logic 514:, which used a mix of 419: 402: 394: 354: 346: 5771:Sum-addressed decoder 5517:Arithmetic logic unit 4644:Classic RISC pipeline 4598:Epiphany architecture 4445:Motorola 68000 series 3547:Apollo service module 3533:Apollo command module 3406:(Wall Street Journal) 3355:Virtual AGC Home Page 3230:Computers Take Flight 2162:on December 29, 2023. 1936: 1835: 1679:asynchronous software 1629:, that implemented a 1615:pre-emptive scheduler 1566: 1368: 1216:(transfer to storage) 831: 823: 811: 773:instruction, and the 637:seven-segment display 588: 580: 524:universal logic gates 522:gates. NOR gates are 465:Following the use of 408: 400: 392: 374:Abort Guidance System 352: 344: 266:The AGC has a 16-bit 234:Apollo command module 194:AGC Assembly Language 5892:Performance per watt 5470:replacement policies 5136:Package on a package 5026:Performance per watt 4930:Pipelined processing 4700:Tomasulo's algorithm 4505:Clipper architecture 4361:Application-specific 4074:Finite-state machine 3929:On crewed spacecraft 3856:Lunar escape systems 3766:Heat Flow Experiment 3677:Lunar Roving Vehicle 2711:Fong, Kevin (2019). 2536:, pp. 154, 157. 2442:. Cambridge, MA: MIT 2371:. pp. 149–250. 2339:. NASA. May 22, 1963 2205:, MIT, July 27, 2001 1847:en route to the Moon 1675:software engineering 1588:magnetic-core memory 1207:(clear and subtract) 1032:instruction (called 655:such as space craft 603:display and keyboard 538:and 36,864 words of 536:magnetic-core memory 428:Charles Stark Draper 154:magnetic-core memory 5924:Digital electronics 5577:Instruction decoder 5529:Floating-point unit 5183:Soft microprocessor 5130:System in a package 4705:Reservation station 4235:Transport-triggered 3828:Lunar Flag Assembly 3797:Crawler-transporter 3552:Apollo Lunar Module 3411:Computer for Apollo 3387:Computer for Apollo 3261:The MIT AGC Project 2585:"The Moon landings" 2247:, MIT, January 2002 1973:Virtual AGC Project 1958:Source code release 1777:16 reenabled them ( 1683:priority scheduling 1545:De Morgan's theorem 1310:fixed-point numbers 597:to the AGC was the 416:integrated circuits 320:Apollo Lunar Module 245:integrated circuits 238:Apollo Lunar Module 21: 5970:Guidance computers 5796:Integrated circuit 5640:Processor register 5294:Baseband processor 4639:Operand forwarding 4099:Cellular automaton 3965:On launch vehicles 3923:Guidance computers 3233:– By James Tomayko 1939: 1923:J. Halcombe Laning 1890:again and another 1849: 1651:Christmas Computer 1603:J. Halcombe Laning 1576: 1375: 1236:was followed by a 1046:(transfer control) 1022:basic instructions 970:instruction format 834: 826: 818: 634:electroluminescent 591: 583: 469:(IC) chips in the 467:integrated circuit 436:architectural work 420: 403: 395: 355: 347: 120:integrated circuit 19: 5957: 5956: 5846: 5845: 5465:Instruction cache 5455:Scratchpad memory 5302: 5301: 5289:Network processor 5218:Network on a chip 5173:Ultra-low-voltage 5124:Multi-chip module 4967: 4966: 4753: 4752: 4740:Branch prediction 4717:Register renaming 4611: 4610: 4593:VISC architecture 4415:Quantum computing 4410:VISC architecture 4292:Secondary storage 4208:Microarchitecture 4168:Register machines 4014: 4013: 3890: 3889: 3642:Apollo/Skylab A7L 3189:978-0-262-26668-0 3062:on 12 April 2021. 2747:978-1-4419-0877-3 2721:BBC World Service 2405:. 14 October 2015 2378:978-1-62683-027-1 1943:fly-by-wire (FBW) 1840:on the Apollo 11 1822:Luminary software 1696:Margaret Hamilton 1687:human-in-the-loop 1580:assembly language 1568:Margaret Hamilton 1342:, followed by an 797:editing locations 740:central registers 730:Central registers 680:inertial guidance 569:representation). 512:guidance computer 376:(AGS, pronounced 228:produced for the 214: 213: 183:Power consumption 104:Guidance computer 6012: 6005:16-bit computers 5919:Processor design 5811:Power management 5693:Instruction unit 5554:Branch predictor 5503: 5502: 5201:System on a chip 5143: 5142: 4983:Transistor count 4907:Flynn's taxonomy 4764: 4763: 4622: 4621: 4425:Addressing modes 4336: 4335: 4282:Memory hierarchy 4146:Hypercomputation 4064:Abstract machine 4041: 4034: 4027: 4018: 4017: 4006: 4005: 3917: 3910: 3903: 3894: 3893: 3882: 3881: 3834:Fallen Astronaut 3626:Scimitar antenna 3611:Apollo TV camera 3443: 3436: 3429: 3420: 3419: 3193: 3164: 3163: 3161: 3160: 3145: 3139: 3138: 3136: 3135: 3121: 3115: 3114: 3112: 3111: 3097: 3091: 3090: 3088: 3087: 3073: 3067: 3063: 3058:. Archived from 3047: 3041: 3040: 3038: 3036: 3021: 3015: 3011: 3006:. Archived from 2994: 2988: 2987: 2985: 2983: 2968: 2962: 2961: 2960: 2959: 2949: 2940: 2934: 2933: 2931: 2929: 2913: 2907: 2906: 2894: 2885: 2884: 2883: 2882: 2866: 2860: 2859: 2858: 2857: 2841: 2835: 2834: 2833: 2832: 2816: 2810: 2809: 2807: 2806: 2792: 2786: 2785: 2784: 2783: 2758: 2752: 2751: 2731: 2725: 2724: 2708: 2702: 2701: 2700:on May 16, 2016. 2696:. Archived from 2689: 2683: 2682: 2675: 2669: 2668: 2666: 2665: 2650: 2641: 2640: 2633: 2627: 2626: 2619: 2613: 2612: 2611: 2610: 2595: 2589: 2588: 2581: 2575: 2569: 2560: 2559: 2557: 2548: 2537: 2531: 2525: 2524: 2522: 2521: 2506: 2500: 2499: 2486: 2480: 2463:Collected Papers 2458: 2452: 2451: 2449: 2447: 2441: 2430: 2415: 2414: 2412: 2410: 2389: 2383: 2382: 2366: 2355: 2349: 2348: 2346: 2344: 2329: 2323: 2322: 2315: 2309: 2308: 2306: 2304: 2294: 2285: 2279: 2278: 2277: 2276: 2261: 2255: 2254: 2253: 2252: 2237: 2231: 2230: 2219: 2213: 2212: 2211: 2210: 2195: 2189: 2188: 2186: 2185: 2170: 2164: 2163: 2147: 2141: 2140: 2139:. 11 March 2017. 2133: 2127: 2126: 2124: 2115: 2109: 2108: 2084: 2075: 2074: 2073: 2072: 2060: 2044: 2033: 1815: 1811: 1799: 1788: 1784: 1780: 1776: 1772: 1769:17 performed an 1768: 1764: 1760: 1640: 1388:fixed-switchable 1371:core rope memory 1349: 1345: 1341: 1337: 1318: 1304: 1294: 1282: 1276: 1269: 1262:double precision 1258:single precision 1255: 1251: 1247: 1243: 1239: 1235: 1231: 1222: 1215: 1206: 1200: 1192: 1186: 1182: 1176: 1170: 1162: 1156: 1147: 1142: 1138: 1134: 1130: 1126: 1118: 1114: 1110: 1106: 1102: 1098: 1094: 1090: 1086: 1064:ones' complement 1058: 1052: 1045: 1035: 1031: 1019: 1015: 1011: 1007: 1003: 999: 995: 991: 987: 983: 979: 972:used 3 bits for 909:ones' complement 790: 780: 772: 707:master frequency 567:ones' complement 543:core rope memory 440:J. H. Laning Jr. 280:core rope memory 276:read-only memory 226:digital computer 165:core rope memory 88: 86: 81: 70: 68: 63: 60:August 1966 29: 22: 18: 6020: 6019: 6015: 6014: 6013: 6011: 6010: 6009: 5960: 5959: 5958: 5953: 5939:Tick–tock model 5897: 5853: 5842: 5782: 5766:Address decoder 5720: 5674: 5670:Program counter 5645:Status register 5626: 5581: 5541:Load–store unit 5508: 5501: 5428: 5397: 5298: 5255:Image processor 5230: 5223: 5193: 5187: 5163:Microcontroller 5153:Embedded system 5141: 5041: 4974: 4963: 4901: 4851: 4749: 4726: 4710:Re-order buffer 4681: 4662:Data dependency 4648: 4607: 4437: 4431: 4330: 4329:Instruction set 4323: 4309:Multiprocessing 4277:Cache hierarchy 4270:Register/memory 4194: 4094:Queue automaton 4050: 4045: 4015: 4010: 3996: 3972:ATHENA computer 3960: 3924: 3921: 3891: 3886: 3872: 3844: 3811: 3787:Mobile Launcher 3775: 3664: 3658: 3630: 3573: 3567: 3516: 3507:Instrument unit 3489: 3483: 3457:Launch vehicles 3452: 3447: 3380:Feature Stories 3367:Eagle Lander 3D 3200: 3190: 3172: 3167: 3158: 3156: 3147: 3146: 3142: 3133: 3131: 3123: 3122: 3118: 3109: 3107: 3099: 3098: 3094: 3085: 3083: 3075: 3074: 3070: 3048: 3044: 3034: 3032: 3022: 3018: 2996: 2995: 2991: 2981: 2979: 2969: 2965: 2957: 2955: 2947: 2941: 2937: 2927: 2925: 2914: 2910: 2895: 2888: 2880: 2878: 2867: 2863: 2855: 2853: 2842: 2838: 2830: 2828: 2817: 2813: 2804: 2802: 2794: 2793: 2789: 2781: 2779: 2777: 2759: 2755: 2748: 2732: 2728: 2709: 2705: 2690: 2686: 2677: 2676: 2672: 2663: 2661: 2651: 2644: 2635: 2634: 2630: 2621: 2620: 2616: 2608: 2606: 2597: 2596: 2592: 2583: 2582: 2578: 2570: 2563: 2555: 2549: 2540: 2532: 2528: 2519: 2517: 2507: 2503: 2498:. 27 July 2021. 2488: 2487: 2483: 2459: 2455: 2445: 2443: 2439: 2431: 2418: 2408: 2406: 2391: 2390: 2386: 2379: 2364: 2356: 2352: 2342: 2340: 2331: 2330: 2326: 2317: 2316: 2312: 2302: 2300: 2292: 2286: 2282: 2274: 2272: 2263: 2262: 2258: 2250: 2248: 2239: 2238: 2234: 2221: 2220: 2216: 2208: 2206: 2197: 2196: 2192: 2183: 2181: 2179:Air & Space 2171: 2167: 2148: 2144: 2135: 2134: 2130: 2122: 2116: 2112: 2106: 2098:, p. 196, 2085: 2078: 2070: 2068: 2062: 2061: 2057: 2053: 2048: 2047: 2034: 2030: 2025: 1993: 1960: 1931: 1830: 1813: 1809: 1797: 1786: 1782: 1778: 1774: 1770: 1766: 1762: 1758: 1738: 1730:Michael Collins 1685:, testing, and 1638: 1631:virtual machine 1561: 1513: 1496:standby allowed 1492: 1451:real-time clock 1418: 1363: 1347: 1343: 1339: 1335: 1316: 1302: 1292: 1280: 1274: 1267: 1253: 1249: 1245: 1244:is followed by 1241: 1237: 1233: 1229: 1220: 1213: 1204: 1198: 1190: 1184: 1180: 1174: 1168: 1160: 1154: 1145: 1140: 1136: 1132: 1128: 1124: 1116: 1112: 1108: 1104: 1100: 1096: 1092: 1088: 1084: 1056: 1050: 1043: 1033: 1029: 1017: 1013: 1009: 1005: 1001: 997: 993: 989: 985: 981: 977: 966: 964:Instruction set 806: 804:Other registers 788: 778: 770: 761:program counter 732: 720:real-time clock 692: 601:, standing for 575: 532: 463: 387: 304: 170: 107: 84: 82: 79: 66: 64: 61: 32: 17: 12: 11: 5: 6018: 6008: 6007: 6002: 5997: 5992: 5987: 5982: 5977: 5972: 5955: 5954: 5952: 5951: 5946: 5944:Pin grid array 5941: 5936: 5931: 5926: 5921: 5916: 5911: 5905: 5903: 5899: 5898: 5896: 5895: 5889: 5884: 5879: 5874: 5869: 5864: 5858: 5856: 5848: 5847: 5844: 5843: 5841: 5840: 5835: 5830: 5825: 5820: 5815: 5814: 5813: 5808: 5803: 5792: 5790: 5784: 5783: 5781: 5780: 5778:Barrel shifter 5775: 5774: 5773: 5768: 5761:Binary decoder 5758: 5757: 5756: 5746: 5741: 5736: 5730: 5728: 5722: 5721: 5719: 5718: 5713: 5705: 5700: 5695: 5690: 5684: 5682: 5676: 5675: 5673: 5672: 5667: 5662: 5657: 5652: 5650:Stack register 5647: 5642: 5636: 5634: 5628: 5627: 5625: 5624: 5623: 5622: 5617: 5607: 5602: 5597: 5591: 5589: 5583: 5582: 5580: 5579: 5574: 5573: 5572: 5561: 5556: 5551: 5550: 5549: 5543: 5532: 5526: 5520: 5513: 5511: 5500: 5499: 5494: 5489: 5484: 5479: 5478: 5477: 5472: 5467: 5462: 5457: 5452: 5442: 5436: 5434: 5430: 5429: 5427: 5426: 5421: 5416: 5411: 5405: 5403: 5399: 5398: 5396: 5395: 5394: 5393: 5383: 5378: 5373: 5368: 5363: 5358: 5353: 5348: 5343: 5338: 5333: 5328: 5323: 5318: 5312: 5310: 5304: 5303: 5300: 5299: 5297: 5296: 5291: 5286: 5281: 5275: 5269: 5263: 5257: 5252: 5246: 5244:AI accelerator 5241: 5235: 5233: 5225: 5224: 5222: 5221: 5215: 5210: 5207:Multiprocessor 5204: 5197: 5195: 5189: 5188: 5186: 5185: 5180: 5175: 5170: 5165: 5160: 5158:Microprocessor 5155: 5149: 5147: 5146:By application 5140: 5139: 5133: 5127: 5121: 5116: 5111: 5106: 5101: 5096: 5091: 5089:Tile processor 5086: 5081: 5076: 5071: 5070: 5069: 5058: 5051: 5049: 5043: 5042: 5040: 5039: 5034: 5029: 5023: 5017: 5011: 5005: 4999: 4998: 4997: 4985: 4979: 4977: 4969: 4968: 4965: 4964: 4962: 4961: 4960: 4959: 4949: 4944: 4943: 4942: 4937: 4932: 4927: 4917: 4911: 4909: 4903: 4902: 4900: 4899: 4894: 4889: 4884: 4883: 4882: 4877: 4875:Hyperthreading 4867: 4861: 4859: 4857:Multithreading 4853: 4852: 4850: 4849: 4844: 4839: 4838: 4837: 4827: 4826: 4825: 4820: 4810: 4809: 4808: 4803: 4793: 4788: 4787: 4786: 4781: 4770: 4768: 4761: 4755: 4754: 4751: 4750: 4748: 4747: 4742: 4736: 4734: 4728: 4727: 4725: 4724: 4719: 4714: 4713: 4712: 4707: 4697: 4691: 4689: 4683: 4682: 4680: 4679: 4674: 4669: 4664: 4658: 4656: 4650: 4649: 4647: 4646: 4641: 4636: 4634:Pipeline stall 4630: 4628: 4619: 4613: 4612: 4609: 4608: 4606: 4605: 4600: 4595: 4590: 4587: 4586: 4585: 4583:z/Architecture 4580: 4575: 4570: 4562: 4557: 4552: 4547: 4542: 4537: 4532: 4527: 4522: 4517: 4512: 4507: 4502: 4501: 4500: 4495: 4490: 4482: 4477: 4472: 4467: 4462: 4457: 4452: 4447: 4441: 4439: 4433: 4432: 4430: 4429: 4428: 4427: 4417: 4412: 4407: 4402: 4397: 4392: 4387: 4386: 4385: 4375: 4374: 4373: 4363: 4358: 4353: 4348: 4342: 4340: 4333: 4325: 4324: 4322: 4321: 4316: 4311: 4306: 4301: 4296: 4295: 4294: 4289: 4287:Virtual memory 4279: 4274: 4273: 4272: 4267: 4262: 4257: 4247: 4242: 4237: 4232: 4227: 4226: 4225: 4215: 4210: 4204: 4202: 4196: 4195: 4193: 4192: 4191: 4190: 4185: 4180: 4175: 4165: 4160: 4155: 4154: 4153: 4148: 4143: 4138: 4133: 4128: 4123: 4118: 4111:Turing machine 4108: 4107: 4106: 4101: 4096: 4091: 4086: 4081: 4071: 4066: 4060: 4058: 4052: 4051: 4044: 4043: 4036: 4029: 4021: 4012: 4011: 4001: 3998: 3997: 3995: 3994: 3989: 3984: 3979: 3974: 3968: 3966: 3962: 3961: 3959: 3958: 3953: 3948: 3943: 3938: 3932: 3930: 3926: 3925: 3920: 3919: 3912: 3905: 3897: 3888: 3887: 3877: 3874: 3873: 3871: 3870: 3863: 3858: 3852: 3850: 3846: 3845: 3843: 3842: 3837: 3830: 3825: 3819: 3817: 3813: 3812: 3810: 3809: 3804: 3799: 3794: 3789: 3783: 3781: 3780:Ground support 3777: 3776: 3774: 3773: 3768: 3763: 3758: 3753: 3748: 3743: 3738: 3733: 3732: 3731: 3726: 3721: 3716: 3711: 3706: 3696: 3691: 3690: 3689: 3679: 3674: 3668: 3666: 3660: 3659: 3657: 3656: 3655: 3654: 3649: 3638: 3636: 3632: 3631: 3629: 3628: 3623: 3618: 3613: 3608: 3603: 3598: 3593: 3588: 3583: 3577: 3575: 3569: 3568: 3566: 3565: 3564: 3563: 3562: 3561: 3549: 3544: 3543: 3542: 3524: 3522: 3518: 3517: 3515: 3514: 3509: 3504: 3499: 3493: 3491: 3488:Launch vehicle 3485: 3484: 3482: 3481: 3476: 3471: 3466: 3460: 3458: 3454: 3453: 3446: 3445: 3438: 3431: 3423: 3417: 3416: 3407: 3401: 3395: 3377: 3376: 3370: 3364: 3358: 3352: 3341: 3340: 3336: 3335: 3329: 3323: 3316: 3315: 3311: 3310: 3305: 3299: 3298: 3294: 3293: 3287: 3278: 3277: 3276: 3270: 3258: 3246: 3234: 3226: 3214: 3205: 3204: 3199: 3198:External links 3196: 3195: 3194: 3188: 3171: 3168: 3166: 3165: 3155:. 10 July 2016 3140: 3116: 3092: 3068: 3050:Garry, Chris. 3042: 3016: 3010:on 7 May 2021. 2989: 2963: 2935: 2908: 2886: 2861: 2836: 2811: 2787: 2776:978-0486471754 2775: 2753: 2746: 2726: 2703: 2684: 2670: 2642: 2628: 2614: 2590: 2576: 2574:, p. 149. 2561: 2538: 2526: 2501: 2481: 2453: 2416: 2384: 2377: 2350: 2324: 2310: 2280: 2256: 2232: 2214: 2190: 2165: 2142: 2128: 2110: 2104: 2088:Hall, Eldon C. 2076: 2054: 2052: 2049: 2046: 2045: 2027: 2026: 2024: 2021: 2020: 2019: 2014: 2009: 2000: 1992: 1989: 1959: 1956: 1930: 1927: 1829: 1826: 1802:Ed's Interrupt 1737: 1734: 1722:Neil Armstrong 1692:Richard Battin 1671:Charles Draper 1582:and stored on 1572:Apollo Project 1560: 1557: 1512: 1509: 1491: 1488: 1474:), decrement ( 1461: 1460: 1454: 1444: 1438: 1432: 1417: 1414: 1362: 1359: 1355:control pulses 1324: 1323: 1320: 1314: 1306: 1300: 1296: 1290: 1283: 1278: 1271: 1265: 1217: 1211: 1208: 1202: 1194: 1188: 1177: 1172: 1157: 1152: 1060: 1054: 1047: 965: 962: 961: 960: 954: 948: 938: 920: 902: 896: 889:1's complement 878: 872: 866: 860: 854: 844: 805: 802: 793: 792: 782: 775:return address 764: 754: 731: 728: 691: 688: 595:user interface 574: 573:DSKY interface 571: 531: 528: 462: 461:Logic hardware 459: 448:Richard Battin 444:Albert Hopkins 386: 383: 382: 381: 370: 365:(LVDC) on the 316:command module 312:control sticks 308:Project Gemini 303: 300: 290:is available. 284:magnetic cores 249:home computers 230:Apollo program 212: 211: 208: 204: 203: 200: 196: 195: 192: 188: 187: 184: 180: 179: 176: 172: 171: 169: 168: 157: 146: 142: 140: 136: 135: 132: 128: 127: 113: 109: 108: 106: 105: 102: 96: 94: 90: 89: 78:July 1975 76: 72: 71: 58: 54: 53: 48: 44: 43: 38: 34: 33: 30: 15: 9: 6: 4: 3: 2: 6017: 6006: 6003: 6001: 5998: 5996: 5993: 5991: 5988: 5986: 5983: 5981: 5978: 5976: 5973: 5971: 5968: 5967: 5965: 5950: 5947: 5945: 5942: 5940: 5937: 5935: 5932: 5930: 5927: 5925: 5922: 5920: 5917: 5915: 5912: 5910: 5907: 5906: 5904: 5900: 5893: 5890: 5888: 5885: 5883: 5880: 5878: 5875: 5873: 5870: 5868: 5865: 5863: 5860: 5859: 5857: 5855: 5849: 5839: 5836: 5834: 5831: 5829: 5826: 5824: 5821: 5819: 5816: 5812: 5809: 5807: 5804: 5802: 5799: 5798: 5797: 5794: 5793: 5791: 5789: 5785: 5779: 5776: 5772: 5769: 5767: 5764: 5763: 5762: 5759: 5755: 5752: 5751: 5750: 5747: 5745: 5742: 5740: 5739:Demultiplexer 5737: 5735: 5732: 5731: 5729: 5727: 5723: 5717: 5714: 5712: 5709: 5706: 5704: 5701: 5699: 5696: 5694: 5691: 5689: 5686: 5685: 5683: 5681: 5677: 5671: 5668: 5666: 5663: 5661: 5660:Memory buffer 5658: 5656: 5655:Register file 5653: 5651: 5648: 5646: 5643: 5641: 5638: 5637: 5635: 5633: 5629: 5621: 5618: 5616: 5613: 5612: 5611: 5608: 5606: 5603: 5601: 5598: 5596: 5595:Combinational 5593: 5592: 5590: 5588: 5584: 5578: 5575: 5571: 5568: 5567: 5565: 5562: 5560: 5557: 5555: 5552: 5547: 5544: 5542: 5539: 5538: 5536: 5533: 5530: 5527: 5524: 5521: 5518: 5515: 5514: 5512: 5510: 5504: 5498: 5495: 5493: 5490: 5488: 5485: 5483: 5480: 5476: 5473: 5471: 5468: 5466: 5463: 5461: 5458: 5456: 5453: 5451: 5448: 5447: 5446: 5443: 5441: 5438: 5437: 5435: 5431: 5425: 5422: 5420: 5417: 5415: 5412: 5410: 5407: 5406: 5404: 5400: 5392: 5389: 5388: 5387: 5384: 5382: 5379: 5377: 5374: 5372: 5369: 5367: 5364: 5362: 5359: 5357: 5354: 5352: 5349: 5347: 5344: 5342: 5339: 5337: 5334: 5332: 5329: 5327: 5324: 5322: 5319: 5317: 5314: 5313: 5311: 5309: 5305: 5295: 5292: 5290: 5287: 5285: 5282: 5279: 5276: 5273: 5270: 5267: 5264: 5261: 5258: 5256: 5253: 5250: 5247: 5245: 5242: 5240: 5237: 5236: 5234: 5232: 5226: 5219: 5216: 5214: 5211: 5208: 5205: 5202: 5199: 5198: 5196: 5190: 5184: 5181: 5179: 5176: 5174: 5171: 5169: 5166: 5164: 5161: 5159: 5156: 5154: 5151: 5150: 5148: 5144: 5137: 5134: 5131: 5128: 5125: 5122: 5120: 5117: 5115: 5112: 5110: 5107: 5105: 5102: 5100: 5097: 5095: 5092: 5090: 5087: 5085: 5082: 5080: 5077: 5075: 5072: 5068: 5065: 5064: 5062: 5059: 5056: 5053: 5052: 5050: 5048: 5044: 5038: 5035: 5033: 5030: 5027: 5024: 5021: 5018: 5015: 5012: 5009: 5006: 5003: 5000: 4995: 4992: 4991: 4989: 4986: 4984: 4981: 4980: 4978: 4976: 4970: 4958: 4955: 4954: 4953: 4950: 4948: 4945: 4941: 4938: 4936: 4933: 4931: 4928: 4926: 4923: 4922: 4921: 4918: 4916: 4913: 4912: 4910: 4908: 4904: 4898: 4895: 4893: 4890: 4888: 4885: 4881: 4878: 4876: 4873: 4872: 4871: 4868: 4866: 4863: 4862: 4860: 4858: 4854: 4848: 4845: 4843: 4840: 4836: 4833: 4832: 4831: 4828: 4824: 4821: 4819: 4816: 4815: 4814: 4811: 4807: 4804: 4802: 4799: 4798: 4797: 4794: 4792: 4789: 4785: 4782: 4780: 4777: 4776: 4775: 4772: 4771: 4769: 4765: 4762: 4760: 4756: 4746: 4743: 4741: 4738: 4737: 4735: 4733: 4729: 4723: 4720: 4718: 4715: 4711: 4708: 4706: 4703: 4702: 4701: 4698: 4696: 4695:Scoreboarding 4693: 4692: 4690: 4688: 4684: 4678: 4677:False sharing 4675: 4673: 4670: 4668: 4665: 4663: 4660: 4659: 4657: 4655: 4651: 4645: 4642: 4640: 4637: 4635: 4632: 4631: 4629: 4627: 4623: 4620: 4618: 4614: 4604: 4601: 4599: 4596: 4594: 4591: 4588: 4584: 4581: 4579: 4576: 4574: 4571: 4569: 4566: 4565: 4563: 4561: 4558: 4556: 4553: 4551: 4548: 4546: 4543: 4541: 4538: 4536: 4533: 4531: 4528: 4526: 4523: 4521: 4518: 4516: 4513: 4511: 4508: 4506: 4503: 4499: 4496: 4494: 4491: 4489: 4486: 4485: 4483: 4481: 4478: 4476: 4473: 4471: 4470:Stanford MIPS 4468: 4466: 4463: 4461: 4458: 4456: 4453: 4451: 4448: 4446: 4443: 4442: 4440: 4434: 4426: 4423: 4422: 4421: 4418: 4416: 4413: 4411: 4408: 4406: 4403: 4401: 4398: 4396: 4393: 4391: 4388: 4384: 4381: 4380: 4379: 4376: 4372: 4369: 4368: 4367: 4364: 4362: 4359: 4357: 4354: 4352: 4349: 4347: 4344: 4343: 4341: 4337: 4334: 4332: 4331:architectures 4326: 4320: 4317: 4315: 4312: 4310: 4307: 4305: 4302: 4300: 4299:Heterogeneous 4297: 4293: 4290: 4288: 4285: 4284: 4283: 4280: 4278: 4275: 4271: 4268: 4266: 4263: 4261: 4258: 4256: 4253: 4252: 4251: 4250:Memory access 4248: 4246: 4243: 4241: 4238: 4236: 4233: 4231: 4228: 4224: 4221: 4220: 4219: 4216: 4214: 4211: 4209: 4206: 4205: 4203: 4201: 4197: 4189: 4186: 4184: 4183:Random-access 4181: 4179: 4176: 4174: 4171: 4170: 4169: 4166: 4164: 4163:Stack machine 4161: 4159: 4156: 4152: 4149: 4147: 4144: 4142: 4139: 4137: 4134: 4132: 4129: 4127: 4124: 4122: 4119: 4117: 4114: 4113: 4112: 4109: 4105: 4102: 4100: 4097: 4095: 4092: 4090: 4087: 4085: 4082: 4080: 4079:with datapath 4077: 4076: 4075: 4072: 4070: 4067: 4065: 4062: 4061: 4059: 4057: 4053: 4049: 4042: 4037: 4035: 4030: 4028: 4023: 4022: 4019: 4009: 3999: 3993: 3990: 3988: 3985: 3983: 3980: 3978: 3975: 3973: 3970: 3969: 3967: 3963: 3957: 3954: 3952: 3949: 3947: 3944: 3942: 3939: 3937: 3934: 3933: 3931: 3927: 3918: 3913: 3911: 3906: 3904: 3899: 3898: 3895: 3885: 3875: 3869: 3868: 3864: 3862: 3859: 3857: 3854: 3853: 3851: 3847: 3841: 3838: 3836: 3835: 3831: 3829: 3826: 3824: 3821: 3820: 3818: 3814: 3808: 3805: 3803: 3800: 3798: 3795: 3793: 3790: 3788: 3785: 3784: 3782: 3778: 3772: 3769: 3767: 3764: 3762: 3759: 3757: 3754: 3752: 3749: 3747: 3744: 3742: 3739: 3737: 3734: 3730: 3727: 3725: 3722: 3720: 3717: 3715: 3712: 3710: 3707: 3705: 3702: 3701: 3700: 3697: 3695: 3692: 3688: 3685: 3684: 3683: 3680: 3678: 3675: 3673: 3670: 3669: 3667: 3663:Lunar surface 3661: 3653: 3650: 3648: 3645: 3644: 3643: 3640: 3639: 3637: 3633: 3627: 3624: 3622: 3619: 3617: 3614: 3612: 3609: 3607: 3604: 3602: 3599: 3597: 3594: 3592: 3589: 3587: 3584: 3582: 3579: 3578: 3576: 3570: 3560: 3559: 3555: 3554: 3553: 3550: 3548: 3545: 3541: 3540: 3536: 3535: 3534: 3531: 3530: 3529: 3526: 3525: 3523: 3519: 3513: 3510: 3508: 3505: 3503: 3500: 3498: 3495: 3494: 3492: 3486: 3480: 3477: 3475: 3472: 3470: 3467: 3465: 3464:Little Joe II 3462: 3461: 3459: 3455: 3451: 3444: 3439: 3437: 3432: 3430: 3425: 3424: 3421: 3414: 3412: 3408: 3405: 3402: 3399: 3396: 3393: 3389: 3388: 3384: 3383: 3382: 3381: 3374: 3371: 3368: 3365: 3362: 3359: 3356: 3353: 3350: 3346: 3343: 3342: 3338: 3337: 3333: 3330: 3327: 3324: 3321: 3318: 3317: 3313: 3312: 3309: 3306: 3304: 3301: 3300: 3296: 3295: 3291: 3288: 3286: 3282: 3279: 3274: 3271: 3268: 3265: 3264: 3262: 3259: 3256: 3252: 3251: 3247: 3244: 3240: 3239: 3235: 3232: 3231: 3227: 3224: 3220: 3219: 3215: 3212: 3211: 3207: 3206: 3202: 3201: 3191: 3185: 3181: 3180: 3174: 3173: 3154: 3150: 3144: 3130: 3126: 3120: 3106: 3102: 3096: 3082: 3078: 3072: 3066: 3061: 3057: 3053: 3046: 3031: 3027: 3020: 3014: 3009: 3005: 3004: 2999: 2993: 2978: 2974: 2971:Burkey, Ron. 2967: 2953: 2946: 2939: 2928:September 18, 2923: 2919: 2912: 2904: 2900: 2893: 2891: 2876: 2872: 2865: 2851: 2847: 2840: 2826: 2822: 2815: 2801: 2797: 2791: 2778: 2772: 2768: 2764: 2757: 2749: 2743: 2739: 2738: 2730: 2722: 2718: 2714: 2707: 2699: 2695: 2692:A.J.S. Rayl. 2688: 2680: 2674: 2660: 2656: 2649: 2647: 2638: 2632: 2624: 2618: 2604: 2600: 2594: 2586: 2580: 2573: 2568: 2566: 2554: 2547: 2545: 2543: 2535: 2530: 2516: 2512: 2505: 2497: 2496: 2491: 2485: 2478: 2474: 2471: 2470: 2465: 2464: 2457: 2438: 2437: 2429: 2427: 2425: 2423: 2421: 2404: 2400: 2399: 2394: 2388: 2380: 2374: 2370: 2363: 2362: 2354: 2338: 2334: 2328: 2320: 2314: 2298: 2291: 2284: 2270: 2266: 2260: 2246: 2242: 2236: 2228: 2224: 2218: 2204: 2200: 2194: 2180: 2176: 2169: 2161: 2157: 2153: 2146: 2138: 2132: 2121: 2114: 2107: 2105:1-56347-185-X 2101: 2097: 2093: 2089: 2083: 2081: 2067: 2066: 2059: 2055: 2042: 2038: 2032: 2028: 2018: 2015: 2013: 2010: 2008: 2007:Space Shuttle 2004: 2001: 1998: 1995: 1994: 1988: 1986: 1982: 1978: 1974: 1970: 1966: 1955: 1953: 1952:Space Shuttle 1948: 1944: 1935: 1926: 1924: 1920: 1917: 1911: 1909: 1905: 1901: 1897: 1893: 1889: 1885: 1881: 1877: 1871: 1869: 1865: 1861: 1857: 1853: 1846: 1845: 1842:Lunar Module 1839: 1834: 1825: 1823: 1819: 1807: 1803: 1794: 1792: 1754: 1752: 1748: 1744: 1733: 1731: 1727: 1723: 1718: 1716: 1715:Space Shuttle 1712: 1707: 1705: 1701: 1697: 1693: 1688: 1684: 1680: 1676: 1672: 1668: 1663: 1660: 1654: 1652: 1648: 1644: 1636: 1635:trigonometric 1632: 1628: 1623: 1621: 1620:metric system 1616: 1612: 1608: 1604: 1600: 1595: 1593: 1589: 1585: 1581: 1573: 1569: 1565: 1556: 1554: 1550: 1546: 1542: 1538: 1534: 1530: 1526: 1521: 1517: 1508: 1504: 1500: 1497: 1487: 1483: 1481: 1478:), or shift ( 1477: 1473: 1469: 1464: 1458: 1455: 1452: 1448: 1445: 1442: 1439: 1436: 1433: 1430: 1427: 1426: 1425: 1423: 1413: 1411: 1405: 1401: 1399: 1394: 1391: 1389: 1385: 1381: 1372: 1367: 1358: 1356: 1351: 1333: 1329: 1328:timing pulses 1321: 1315: 1311: 1307: 1301: 1297: 1291: 1288: 1284: 1279: 1272: 1266: 1263: 1259: 1226: 1218: 1212: 1209: 1203: 1195: 1189: 1178: 1173: 1166: 1158: 1153: 1149: 1122: 1081: 1077: 1073: 1069: 1065: 1061: 1055: 1048: 1042: 1041: 1040: 1037: 1027: 1023: 1008:(basic), and 975: 971: 958: 955: 952: 949: 946: 942: 939: 936: 932: 928: 924: 921: 918: 914: 910: 906: 903: 900: 897: 894: 890: 886: 882: 879: 876: 873: 870: 867: 864: 861: 858: 855: 852: 848: 845: 842: 839: 838: 837: 830: 822: 815: 810: 801: 798: 786: 783: 776: 768: 765: 762: 758: 755: 752: 748: 745: 744: 743: 741: 737: 727: 725: 721: 717: 716: 710: 708: 704: 700: 697: 687: 685: 681: 677: 672: 670: 666: 662: 658: 654: 650: 646: 642: 638: 635: 630: 628: 624: 620: 616: 612: 608: 604: 600: 596: 587: 579: 570: 568: 564: 561:bit, and one 560: 556: 552: 548: 544: 541: 537: 527: 525: 521: 517: 513: 510: 505: 503: 499: 495: 491: 487: 483: 478: 476: 472: 468: 458: 455: 453: 449: 445: 441: 437: 433: 432:Eldon C. Hall 429: 425: 417: 414: 411: 407: 399: 391: 379: 375: 371: 368: 364: 360: 359: 358: 351: 343: 339: 337: 333: 329: 325: 321: 317: 313: 309: 299: 297: 291: 289: 285: 281: 277: 273: 269: 264: 262: 261:Commodore PET 258: 254: 250: 246: 243: 239: 235: 231: 227: 223: 219: 209: 205: 201: 197: 193: 189: 185: 181: 177: 173: 166: 162: 159:36,864 words 158: 155: 151: 147: 144: 143: 141: 137: 133: 129: 125: 121: 118: 114: 110: 103: 101: 98: 97: 95: 91: 77: 73: 59: 55: 52: 49: 45: 42: 39: 35: 28: 23: 5949:Chip carrier 5887:Clock gating 5806:Mixed-signal 5703:Write buffer 5680:Control unit 5492:Clock signal 5335: 5231:accelerators 5213:Cypress PSoC 4870:Simultaneous 4687:Out-of-order 4319:Neuromorphic 4200:Architecture 4158:Belt machine 4151:Zeno machine 4084:Hierarchical 3940: 3865: 3832: 3823:Lunar plaque 3590: 3556: 3537: 3410: 3386: 3379: 3378: 3249: 3237: 3229: 3222: 3217: 3209: 3178: 3157:. Retrieved 3152: 3143: 3132:. Retrieved 3128: 3119: 3108:. Retrieved 3104: 3095: 3084:. Retrieved 3080: 3071: 3060:the original 3055: 3045: 3033:. Retrieved 3029: 3019: 3008:the original 3001: 2992: 2980:. Retrieved 2976: 2973:"VirtualAGC" 2966: 2956:, retrieved 2951: 2938: 2926:. Retrieved 2921: 2911: 2902: 2879:, retrieved 2874: 2864: 2854:, retrieved 2849: 2839: 2829:, retrieved 2824: 2814: 2803:. Retrieved 2799: 2790: 2780:, retrieved 2766: 2756: 2736: 2729: 2716: 2706: 2698:the original 2687: 2673: 2662:. Retrieved 2658: 2631: 2617: 2607:, retrieved 2602: 2593: 2579: 2572:Mindell 2008 2534:Mindell 2008 2529: 2518:. Retrieved 2514: 2504: 2493: 2484: 2476: 2467: 2461: 2456: 2444:. Retrieved 2435: 2407:. Retrieved 2396: 2387: 2360: 2353: 2341:. Retrieved 2336: 2327: 2313: 2301:. Retrieved 2296: 2283: 2273:, retrieved 2268: 2259: 2249:, retrieved 2244: 2235: 2226: 2217: 2207:, retrieved 2202: 2193: 2182:. Retrieved 2178: 2168: 2160:the original 2155: 2145: 2131: 2113: 2091: 2069:, retrieved 2064: 2058: 2040: 2036: 2031: 1997:Apollo PGNCS 1961: 1947:F-8 Crusader 1940: 1921: 1912: 1899: 1895: 1891: 1887: 1883: 1879: 1875: 1872: 1868:cycle steals 1863: 1859: 1850: 1843: 1818:lunar module 1801: 1795: 1791:far pointers 1755: 1739: 1719: 1708: 1700:person-years 1664: 1655: 1650: 1646: 1624: 1601:designed by 1596: 1577: 1552: 1548: 1540: 1536: 1532: 1528: 1524: 1522: 1518: 1514: 1505: 1501: 1495: 1493: 1490:Standby mode 1484: 1479: 1475: 1471: 1465: 1462: 1456: 1446: 1440: 1434: 1428: 1419: 1410:parity alarm 1409: 1406: 1402: 1398:memory cycle 1397: 1395: 1392: 1387: 1383: 1379: 1376: 1354: 1352: 1331: 1327: 1325: 1286: 1165:base address 1144: 1079: 1075: 1071: 1067: 1038: 1025: 1021: 967: 956: 950: 944: 940: 934: 930: 926: 922: 916: 912: 904: 898: 892: 884: 880: 874: 868: 862: 856: 846: 840: 835: 796: 794: 791:instructions 784: 781:instructions 766: 756: 746: 739: 733: 723: 713: 711: 706: 693: 673: 665:metric units 631: 626: 622: 606: 602: 598: 592: 533: 509:Minuteman II 506: 479: 464: 456: 421: 377: 356: 335: 332:Apollo PGNCS 305: 292: 265: 221: 217: 215: 122:(IC) chips ( 75:Discontinued 47:Manufacturer 5734:Multiplexer 5698:Data buffer 5409:Single-core 5381:bit slicing 5239:Coprocessor 5094:Coprocessor 4975:performance 4897:Cooperative 4887:Speculative 4847:Distributed 4806:Superscalar 4791:Instruction 4759:Parallelism 4732:Speculative 4564:System/3x0 4436:Instruction 4213:Von Neumann 4126:Post–Turing 3867:Moon Museum 3635:Space suits 3349:AGC Replica 3345:AGC Replica 3326:Source code 3105:ibiblio.org 2409:1 September 2343:19 February 2337:Archive.org 2299:. p. 9 1908:Jack Garman 1904:Steve Bales 1838:Buzz Aldrin 1726:Buzz Aldrin 1584:rope memory 1384:fixed-fixed 1332:subsequence 751:accumulator 520:diode logic 492:(RTL) in a 288:core memory 148:2048 words 37:Invented by 5964:Categories 5854:management 5749:Multiplier 5610:Logic gate 5600:Sequential 5507:Functional 5487:Clock rate 5460:Data cache 5433:Components 5414:Multi-core 5402:Core count 4892:Preemptive 4796:Pipelining 4779:Bit-serial 4722:Wide-issue 4667:Structural 4589:Tilera ISA 4555:MicroBlaze 4525:ETRAX CRIS 4420:Comparison 4265:Load–store 4245:Endianness 3956:IBM AP-101 3816:Ceremonial 3647:Beta cloth 3574:components 3572:Spacecraft 3521:Spacecraft 3502:J-2 engine 3497:F-1 engine 3490:components 3400:(BBC News) 3159:2021-09-09 3134:2021-09-09 3110:2021-09-09 3086:2021-09-09 2958:2009-09-01 2881:2010-02-04 2856:2009-09-01 2831:2009-09-01 2805:2016-07-17 2782:2009-08-30 2664:2018-11-25 2609:2010-03-21 2520:2016-08-17 2275:2009-08-30 2251:2009-08-30 2209:2009-08-30 2184:2018-12-15 2071:2018-08-27 2051:References 1977:MIT Museum 1967:intern to 1864:1201 alarm 1860:1202 alarm 1511:Data buses 1422:interrupts 1319:(subtract) 1295:(multiply) 1193:(exchange) 1080:Diminished 1072:minus zero 847:Bank/Fbank 611:calculator 607:"DIS-kee". 553:-internal 547:parity bit 477:IC chips. 438:came from 272:parity bit 207:Dimensions 57:Introduced 5788:Circuitry 5708:Microcode 5632:Registers 5475:coherence 5450:CPU cache 5308:Word size 4973:Processor 4617:Execution 4520:DEC Alpha 4498:Power ISA 4314:Cognitive 4121:Universal 3665:equipment 3474:Saturn IB 3415:– youtube 3375:– youtube 3035:19 August 2717:bbc.co.uk 2479:, p. 131. 2303:29 August 1836:DSKY and 1806:Ed Smally 1643:the 1960s 1611:interrupt 1609:, and an 1597:A simple 1592:Apollo 14 1225:overflows 1068:plus zero 895:register) 736:registers 540:read-only 504:plastic. 498:wire wrap 494:flat-pack 302:Operation 278:known as 236:(CM) and 134:2.048 MHz 131:Frequency 115:Discrete 112:Processor 5726:Datapath 5419:Manycore 5391:variable 5229:Hardware 4865:Temporal 4545:OpenRISC 4240:Cellular 4230:Dataflow 4223:modified 3951:IBM TC-1 3539:Columbia 3479:Saturn V 3469:Saturn I 3153:Engadget 2982:10 April 2515:MIT News 2090:(1996), 1991:See also 1916:synchros 1874:command 1804:, after 1751:Apollo 1 1743:Apollo 4 1736:Block II 1613:-driven 1559:Software 1468:counters 1305:(divide) 947:register 851:kiloword 657:attitude 563:sign bit 559:overflow 482:NOR gate 452:Raytheon 434:. Early 410:Flatpack 367:Saturn V 328:Apollo 8 324:Apollo 7 318:and the 253:Apple II 224:) was a 191:Language 100:Avionics 51:Raytheon 5902:Related 5833:Quantum 5823:Digital 5818:Boolean 5716:Counter 5615:Quantum 5376:512-bit 5371:256-bit 5366:128-bit 5209:(MPSoC) 5194:on chip 5192:Systems 5010:(FLOPS) 4823:Process 4672:Control 4654:Hazards 4540:Itanium 4535:Unicore 4493:PowerPC 4218:Harvard 4178:Pointer 4173:Counter 4131:Quantum 3849:Related 3528:Apollo 3390:(1965) 3170:Sources 3065:Alt URL 3013:Alt URL 2977:iBiblio 2495:YouTube 2446:15 June 1785:called 1447:T3Rrupt 1441:Keyrupt 1121:IBM 360 1074:.) The 724:standby 696:crystal 676:sextant 661:delta-V 653:vectors 649:decimal 475:silicon 413:silicon 242:silicon 117:silicon 85:1975-07 83: ( 67:1966-08 65: ( 5838:Switch 5828:Analog 5566:(IMC) 5537:(MMU) 5386:others 5361:64-bit 5356:48-bit 5351:32-bit 5346:24-bit 5341:16-bit 5336:15-bit 5331:12-bit 5168:Mobile 5084:Stream 5079:Barrel 5074:Vector 5063:(GPU) 5022:(SUPS) 4990:(IPC) 4842:Memory 4835:Vector 4818:Thread 4801:Scalar 4603:Others 4550:RISC-V 4515:SuperH 4484:Power 4480:MIPS-X 4455:PDP-11 4304:Fabric 4056:Models 3977:ASC-15 3361:Moonjs 3186: 3129:GitHub 3056:GitHub 3030:Quartz 3003:GitHub 2877:, NASA 2852:, NASA 2827:, NASA 2800:GitHub 2773: 2744: 2375: 2102: 2003:AP-101 1985:GitHub 1969:GitHub 1810:RESUME 1798:EDRUPT 1787:EXTEND 1779:RELINT 1771:INHINT 1763:RESUME 1711:Skylab 1457:Uprupt 1429:Dsrupt 1361:Memory 1248:ZERO ( 1175:RESUME 1151:holes. 1148:-holes 1115:and a 1034:EXTEND 1016:, and 1004:, and 974:opcode 777:after 759:: The 749:: The 726:mode. 715:scaler 690:Timing 641:relays 617:, and 555:16-bit 549:. The 530:Memory 426:under 385:Design 259:, and 257:TRS-80 199:Weight 139:Memory 126:based) 5894:(PPW) 5852:Power 5744:Adder 5620:Array 5587:Logic 5548:(TLB) 5531:(FPU) 5525:(AGU) 5519:(ALU) 5509:units 5445:Cache 5326:8-bit 5321:4-bit 5316:1-bit 5280:(TPU) 5274:(DSP) 5268:(PPU) 5262:(VPU) 5251:(GPU) 5220:(NoC) 5203:(SoC) 5138:(PoP) 5132:(SiP) 5126:(MCM) 5067:GPGPU 5057:(CPU) 5047:Types 5028:(PPW) 5016:(TPS) 5004:(IPS) 4996:(CPI) 4767:Level 4578:S/390 4573:S/370 4568:S/360 4510:SPARC 4488:POWER 4371:TRIPS 4339:Types 3558:Eagle 3413:video 2948:(PDF) 2922:Wired 2659:WIRED 2556:(PDF) 2440:(PDF) 2365:(PDF) 2293:(PDF) 2123:(PDF) 2023:Notes 1852:PGNCS 1844:Eagle 1814:ZRUPT 1775:INDEX 1767:INDEX 1759:INDEX 1659:octal 1480:Shinc 1435:Erupt 1373:(ROM) 1299:sign. 1270:(add) 1185:INDEX 1181:INDEX 1169:INDEX 1161:INDEX 1155:INDEX 1139:*+2, 1135:*+2, 986:INDEX 885:adder 863:Sbank 857:Ebank 699:clock 645:octal 502:epoxy 336:pings 310:with 175:Ports 5872:ACPI 5605:Glue 5497:FIFO 5440:Core 5178:ASIP 5119:CPLD 5114:FPOA 5109:FPGA 5104:ASIC 4957:SPMD 4952:MIMD 4947:MISD 4940:SWAR 4920:SIMD 4915:SISD 4830:Data 4813:Task 4784:Word 4530:M32R 4475:MIPS 4438:sets 4405:ZISC 4400:NISC 4395:OISC 4390:MISC 4383:EPIC 4378:VLIW 4366:EDGE 4356:RISC 4351:CISC 4260:HUMA 4255:NUMA 3982:D-17 3285:Dsky 3283:and 3184:ISBN 3037:2016 2984:2021 2930:2019 2771:ISBN 2742:ISBN 2448:2021 2411:2019 2373:ISBN 2369:NASA 2345:2024 2305:2023 2100:ISBN 2096:AIAA 2041:0668 2037:noun 1981:NASA 1975:and 1965:NASA 1900:1668 1896:1668 1892:1202 1888:1668 1884:1202 1880:1668 1876:1668 1745:and 1728:and 1618:the 1476:Minc 1472:Pinc 1380:Bank 1369:AGC 1281:MASK 1131:was 1006:MASK 968:The 915:and 627:Noun 623:Verb 619:Noun 615:Verb 599:DSKY 593:The 518:and 372:the 361:The 268:word 216:The 186:55 W 93:Type 5867:APM 5862:PMU 5754:CPU 5711:ROM 5482:Bus 5099:PAL 4774:Bit 4560:LMC 4465:ARM 4460:x86 4450:VAX 3392:MIT 3255:PDF 3243:PDF 1647:YUL 1639:MXV 1549:AND 1537:AND 1533:AND 1348:MP3 1344:MP1 1340:MP0 1287:and 1254:XCH 1250:CAF 1246:CAF 1191:XCH 1146:CCS 1129:CCS 1125:BCT 1123:'s 1113:CCS 1109:CCS 1105:CCS 1101:CCS 1097:CCS 1093:CCS 1089:CCS 1085:CCS 1057:CCS 990:XCH 982:CCS 957:OUT 647:or 551:CPU 378:ags 222:AGC 161:ROM 150:RAM 124:RTL 5966:: 5801:3D 3151:. 3127:. 3103:. 3079:. 3054:. 3028:. 3000:. 2975:. 2950:, 2920:. 2901:, 2889:^ 2873:, 2848:, 2823:, 2798:. 2765:, 2719:. 2715:. 2657:. 2645:^ 2601:, 2564:^ 2541:^ 2513:. 2492:. 2419:^ 2401:. 2395:. 2367:. 2335:. 2295:. 2267:, 2243:, 2225:, 2201:, 2177:. 2154:. 2079:^ 1987:. 1824:. 1793:. 1783:TC 1753:. 1732:. 1724:, 1713:, 1681:, 1594:. 1553:OR 1541:OR 1529:OR 1525:OR 1424:: 1336:MP 1317:SU 1303:DV 1293:MP 1275:AD 1268:AD 1252:= 1242:TS 1238:TC 1234:TS 1230:TS 1221:TS 1214:TS 1205:CS 1199:TS 1141:AD 1137:TC 1133:TC 1117:TC 1051:TC 1044:TC 1030:TC 1018:DV 1014:MP 1012:, 1010:SU 1002:AD 1000:, 998:TS 996:, 994:CS 992:, 988:, 984:, 980:, 978:TC 951:IN 931:SQ 869:SQ 789:MP 785:LP 779:TC 771:DV 742:: 621:. 446:, 442:, 338:. 263:. 255:, 4040:e 4033:t 4026:v 3916:e 3909:t 3902:v 3442:e 3435:t 3428:v 3351:. 3253:( 3241:( 3225:) 3192:. 3162:. 3137:. 3113:. 3089:. 3039:. 2986:. 2932:. 2808:. 2750:. 2723:. 2667:. 2639:. 2523:. 2450:. 2413:. 2381:. 2347:. 2307:. 2187:. 2125:. 1747:6 1574:. 1453:. 1201:. 1183:( 945:B 941:C 937:. 935:S 927:B 923:B 919:) 917:Y 913:X 905:U 899:Y 893:Z 881:X 875:G 841:S 767:Q 757:Z 747:A 565:( 220:( 167:) 163:( 156:) 152:( 87:) 69:)

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Apollo Guidance Computer

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