Commodore D9060
The Commodore D9060 hard drive was the only family of hard drives that Commodore made for the home and business market. The electronics of the CBM D9090 and the CBM D9060 are identical. The only difference is the size of the installed hard disk, which is set with a jumper to differentiate between 4 or 6 hard disk heads. Originally intended for the PET series, they could also be used with the Commodore 64 and later models with an adapter.
Technical specifications
| model | Type | rpm | cylinder | Heads | Raw capacity | Formatted size | Free blocks | Free space |
|---|---|---|---|---|---|---|---|---|
| D9060 | TANDON TM602S | 3600 ± 1% | 153 | 4th | 6.4 MB | 4.98 MB | 19,442 | 4860.5 kB |
| D9090 | TANDON TM603S | 3600 ± 1% | 153 | 6th | 9.6 MB | 7.47 MB | 29,162 | 7290.5 kB |
- On the D9090, 25% of the hard drive is never used
Internally, the system was composed of four parts:
- CBM DOS 3.0 PCB
- SCSI controller
- Hard disk drive
- power adapter
Input voltages: 100, 117, 220, 240 V AC
CBM DOS 3.0 PCB
The DOS PCB (circuit board) consists of the following electronic components:
- 3 × ROMs (two for CBM-DOS communication with computer, one for SASI communication for hard disk formatting, track & sector layout, 4 or 6 heads)
- 4 or 6 read / write heads can only be selected by a hardware jumper located on the front of the DOS board
- 2 × 6502 microprocessors
- 2 × 6532 RIOT (RAM-I / O-Timer) chip
- 1 × 6522 I / O chip
Use for the Commodore 64/128
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The D9090 and D9060 hard drive models were a luxury for users of a Commodore 64 or Commodore 128 in the early 1980s to have all of their programs and games in one place. The system was 7 times faster than the standard Commodore 1541 drive with only "664 BLOCKS FREE" (166 kB), whereas the D9090 hard disk scored with an unbelievable "29,162 BLOCKS FREE" (7290 kB).
By the late 1980s, the Commodore 64 had overtaken all other Commodore 8-bit machines largely because of the large number of users around the world and also the market support from so many third party software and hardware companies. As a result, the older IEEE-488 floppy disk drives and hard disk drives were purchased by a large number of C64 owners in order to establish a connection to their computers with an IEEE-488 interface. This put pressure on the supply of these devices, which was requested by Commodore 64/128 users.
Hard disk on the C64 versus 1541 with floppy speeder
The data comes from the article Original Commodore hard drive on the C64 of the 64'er magazine 11/1988, page 150.
Web links
Individual evidence
- ↑ a b Tandon OEM operating and service manual (1982)
- ↑ a b c d Hard Drive Specifications
- ↑ Article in the 64'er magazine 11/1988, original Commodore hard drive on the C64, page 148-150
