24:
244:
They are notable for the disk drive having twice the processing power than the connected computer in having two 1MHz 6502 processors sharing operation of communication and disk operation, though only supporting 4k of main memory. The disk operating system is actually contained within the disk drive
346:, so they cannot read or write 5¼-inch disks formatted by lower-capacity 48-tpi models, such as the Commodore 1541 or 4040. They also cannot read or write 5¼-inch disks formatted by 96-tpi drives, such as the 640 kilobyte IBM PC disk or 880 kilobyte Commodore
291:
are double-sided drives. Double-sided drives can fully read and write to disks formatted by single-sided drives, but single-sided drives can only read and write to the bottom side of disks formatted by double-sided drives.
245:
unit with commands being sent via the 8 bit GPIB interface where the system decodes the message and carries out the requested operation such as formatting a disk without further involvement from the connected computer.
436:
The BAM (block availability map) begins on 38/0 (track 38, sector 0), and continues on 38/3. On the 8250, the BAM extends further to 38/6 and 38/9. The remaining sectors on track 38 are available for general use.
350:
disk, due to the minor difference in track spacing. Lastly, they cannot read or write high-density 5¼-inch disks due to both the difference in track spacing and the difference in write head coercivity
443:$ 00–01 T/S reference to the next BAM sector, or 00/FF if last. 02 DOS version ('C') 04 Lowest BAM track in this block 05 Highest+1 BAM track in this block 06-FF BAM for 50 tracks
433:$ 00–01 T/S reference to the first BAM (block availability map) sector 02 DOS version ('C') 06-16 Disk label, $ A0 padded 18-19 Disk ID 1B-1C DOS type('2C')
605:
727:
627:
733:
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276:
across the entire disk. Formatted capacity is approximately 0.5 megabyte per side, or 1 megabyte (1,066,496 bytes) in 4166 blocks total.
260:
with a track spacing of 100 tracks-per-inch, for a total of 77 logical tracks per side. Data is encoded using
Commodore's proprietary
581:
452:
693:
672:
759:
504:
481:
5¼-inch double-density drives with a track spacing of 96 or 100 tpi are commonly referred to as "quad-density" drives.
427:
The disk header is on 39/0 (track 39, sector 0), with the directory residing on the remaining 28 sectors of track 39.
538:
273:
1014:
752:
631:
241:
series of computers. The drives offered improved storage capacities over previous
Commodore drive models.
162:
6.5 in × 15.0 in × 14.35 in (165 mm × 381 mm × 364 mm)
261:
776:
230:
99:
120:
175:
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is used for track alignment. Like most other
Commodore disk drives, these drives utilize
8:
802:
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105:
457:
269:
226:
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87:
628:"Manuals | Technical Comparison of Commodore 1541 2040 4040 8050 8250 Drives"
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323:, is housed in a shorter dual-drive case that is stylistically similar to the
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include latch sensors that can detect when a disk is inserted or removed.
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Commodore Disk
Reference Manual for D9090 D9060 8250 8050 4040 2031
328:
144:
352:
774:
194:
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978:
673:"Restoration & Repair A Commodore Dual Disk 8250 LP"
546:. Commodore Business Machines, Inc. 1985. pp. 1, 5.
589:. Commodore Business Machines, Inc. 1980. pp. 5–6.
613:. Commodore Business Machines, Inc. pp. 5–6, 8–9.
327:. All models include an internal power supply and an
719:
TOOLS specifically for the SFD1001 & 8250 Drives.
583:
User's Manual for CBM 5¼-inch Dual Floppy Disk Drives
355:for double-density, 600-oersted for high-density).
1006:
311:is housed in a single-drive case similar to the
728:Technical comparison of Commodore floppy drives
303:are housed in a dual-drive case similar to the
659:"Secret Weapons of Commodore: The Disk Drives"
600:
598:
596:
576:
574:
572:
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331:data connector on the rear of the case. The
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540:Service Manual 8050 • 8250 Dual Disk Drives
767:
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652:
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648:
555:
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22:
533:
531:
529:
527:
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424:Total Sectors: 2083 (4166 for the 8250)
645:
550:
28:Commodore 8050 floppy-disk drive, with
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622:
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499:
497:
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522:
283:is a single-sided drive, whereas the
665:
82:2 × 5¼" double-sided, double-density
74: (equivalent to $ 6,300 in 2023)
739:Daves Old Computers - Commodore PET
694:"Commodore 8250 LP Dual Disk Drive"
686:
617:
494:
13:
14:
1026:
710:
253:All three models utilize 5¼-inch
248:
40:Commodore Business Machines, Inc.
319:, a low-profile revision of the
741:(floppy drive images and info)
717:optusnet.com.au/../SFD1001.htm
475:
358:
1:
488:
630:. 2011-03-30. Archived from
414:
403:
392:
381:
185:, 4000-series, 8000-series,
7:
453:List of floppy disk formats
446:
440:BAM Layout 38/0, 3, (6, 9)
10:
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734:Commodore Dual Disk Drives
233:, primarily for its 8-bit
154:110-117 V, 220-24 0V, 50 W
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818:
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561:"PET index - Disk drives"
201:
174:
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135:521 KB/side, 1042 KB/disk
131:
115:
98:
86:
78:
67:
52:
44:
36:
21:
723:Commodore Knowledge Base
468:
730:(with drive capacities)
231:Commodore International
170:28 lb (13 kg)
123:), 16 KB ROM (2 ×
1015:CBM floppy disk drives
463:Group coded recording
342:These drives are not
262:group coded recording
197:with IEEE-488 adapter
775:Storage devices for
505:"Commodore SuperPET"
379: 1-39, 78-116
119:4 KB SRAM (8 ×
430:Header Layout 39/0
274:average bit density
18:
458:Zone bit recording
270:zone bit recording
227:floppy disk drives
223:Commodore SFD-1001
68:Introductory price
16:
1002:
1001:
998:
997:
422:
421:
369:Sectors Per Track
211:
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657:Cameron Kaiser.
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507:. Archived from
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229:manufactured by
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88:Operating system
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63:
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31:
26:
19:
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412:65-77, 142-154
401:54-64, 131-141
390:40-53, 117-130
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272:to maintain an
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93:CBM DOS 2.5/2.7
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711:External links
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313:Commodore 1541
305:Commodore 4040
266:Soft sectoring
255:double-density
250:
249:Specifications
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219:Commodore 8250
215:Commodore 8050
209:
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206:Commodore 4040
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17:Commodore 8050
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820:Parallel IEEE
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634:on 2008-10-11
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511:on 2010-06-20
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178:compatibility
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698:. Retrieved
688:
677:. Retrieved
675:. 2013-12-17
667:
636:. Retrieved
632:the original
606:
582:
539:
513:. Retrieved
509:the original
477:
439:
435:
429:
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343:
341:
336:
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324:
320:
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308:
307:drive. The
300:
296:
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288:
284:
280:
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258:floppy disks
252:
243:
225:are 5¼-inch
222:
218:
214:
212:
191:Commodore 64
140:Connectivity
53:Release date
48:Floppy drive
37:Manufacturer
371:(256 bytes)
359:Disk Layout
202:Predecessor
30:CBM 2001 PC
990:Lt. Kernal
986:Hard drive
912:Serial CBM
893:Hard drive
700:2016-04-02
679:2016-04-02
638:2016-04-02
515:2016-04-02
489:References
159:Dimensions
794:Datasette
777:Commodore
344:dual-mode
295:Both the
264:scheme.
143:Parallel
72:US$ 1,695
1009:Category
953:Indus GT
889:SFD-1001
788:Cassette
447:See also
374:Sectors
329:IEEE-488
325:SFD-1001
309:SFD-1001
289:SFD-1001
176:Backward
145:IEEE-488
106:MOS 6502
960:3½-inch
919:5¼-inch
850:5¼-inch
782:systems
353:oersted
315:. The
132:Storage
58: (
969:CMD FD
948:MSD SD
827:8-inch
696:. 2010
317:8250LP
221:, and
195:VIC-20
116:Memory
780:8-bit
611:(PDF)
587:(PDF)
544:(PDF)
469:Notes
385:1131
366:Track
351:(300-
348:Amiga
151:Power
110:1 MHz
79:Media
979:SCSI
964:1581
943:1571
938:1570
933:1551
928:1541
923:1540
902:9090
897:9060
884:8250
879:8050
874:4040
869:4031
864:3040
859:2040
854:2031
846:8280
841:8062
836:8061
831:8060
812:Disk
803:1531
798:1530
418:299
407:275
396:378
337:8250
335:and
333:8050
321:8250
301:8250
299:and
297:8050
287:and
285:8250
281:8050
279:The
237:and
213:The
187:B128
167:Mass
125:2364
121:2114
104:2 ×
60:1980
56:1980
45:Type
239:PET
235:CBM
183:PET
100:CPU
1011::
647:^
619:^
595:^
569:^
552:^
524:^
496:^
415:23
404:25
393:27
382:29
217:,
193:,
189:;
127:)
108:@
768:e
761:t
754:v
703:.
682:.
661:.
641:.
563:.
518:.
62:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
