Commodore 1551

Commodore 1551
View of a European Commodore 1551 disk drive, showing the connector
CodenameSFS481[1]
ManufacturerCommodore Business Machines, Inc.
Product familyCommodore 264 series
TypeFloppy drive
Release date1984; 40 years ago (1984)[2]
Introductory priceUS$400[2] (1984) equivalent to $1,200 in 2023
Discontinued1986[2]
Media5.25" floppy disk Single Sided, Single Density[3]
Operating systemCBM DOS 2.6[3]
CPUMOS 6510T[4]: 86 
Memory
  • 2 kB RAM[4]: 86 
  • 16 kB ROM[4]: 86 
Storage170 kB[3][4]: 86 
ConnectivityTED parallel port[3]
Dimensions97 mm × 200 mm × 374 mm
3.8 in × 7.9 in × 14.7 in[4]: 86 
Mass10.5 kg
23 lb[4]: 86 
Backward
compatibility
PredecessorCommodore 1541
Successor
Rear view
Adapter interior

The Commodore 1551 (originally introduced as the SFS 481) is a floppy disk drive for the Commodore Plus/4 home computer. It resembles a charcoal-colored Commodore 1541 and plugs into the cartridge port, providing faster access than the C64/1541 combination. Commodore reportedly planned an interface to allow use of the 1551 with the C64, but it was never released.

Aside from faster access, the drive is very similar to the 1541. Like the 1541, it is a single-sided 170-kilobyte drive for 5¼" disks, with each disk split into 664 256-byte blocks available for user data plus 19 blocks for DOS data and directory; the file system makes each block its own cluster.[4]: 86 

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  3. ^ a b c d Cite error: The named reference Commodore_1551 was invoked but never defined (see the help page).
  4. ^ a b c d e f g Cite error: The named reference 198410_1551_UsersGuide was invoked but never defined (see the help page).