Amstrad DDI-1
| Amstrad DDI-1 | |
|---|---|
.jpg) |
|
| DDI-1 drive and disc interface (Amstrad service manual cover) | |
| Manufacturer | Amstrad Consumer Electronics plc |
| Type | 3-inch floppy disc drive and interface |
| Interface | CPC 464 expansion edge connector (marked FLOPPY DISC) |
| Compatible | Amstrad CPC 464 |
| Dimensions | Drive 75 × 105 × 280 mm; interface 75 × 165 × 35 mm |
| Weight | Drive 1.6 kg; interface 0.2 kg |
| Model | DDI-1 (first drive with interface); FD-1 (second drive) |
| Power | Own mains supply, 240 V AC 50 Hz |
| Storage | 169K (SYSTEM), 178K (DATA) or 154K (IBM) per side |
| Media | 3-inch compact floppy disc (Amsoft CF-2) |
The Amstrad DDI-1 is the 3-inch disc system Amstrad sold for the Amstrad CPC 464: a disc drive with its own mains supply, a plug-on interface unit and a ribbon cable. The interface holds the disc controller and an expansion ROM with AMSDOS and the machine-dependent parts of CP/M and LOGO. The FD-1 is the second drive. Amstrad's service manual covers both.[1] The user instructions are dated 1984.[2]
Design
[edit | edit source]The drive follows the Hitachi/Panasonic 3-inch standard. Amstrad set the software for a 12 ms step rate and 30 ms settling time, and the system controls at most two drives. Each drive has its own integral mains power supply, and the first drive's supply also powers the interface through the connecting cable.[1]
The mechanism is a Compact FDD EME-150A (part 190005) with a stepper motor, head assembly, capstan motor and drive belt listed as separate spares.[1] The interface board carries the µPD765AC disc controller (IC101), the FDC9229BT data separator (IC102) and the TMM-23128P-1951 ROM (IC104).[1]
| Format | Sectors per track | Reserved | Capacity per side |
|---|---|---|---|
| SYSTEM | 9 | 2 tracks for CP/M; 2K directory | 169K |
| DATA only | 9 | None; 2K directory | 178K |
| IBM | 8 | 1 track; 2K directory | 154K |
All three formats are single sided, double density, with 512-byte sectors, 40 tracks and a 2:1 sector interleave. The format is detected automatically when a disc is accessed. Either side of a disc can be used by turning it over.[1]
Power supply
[edit | edit source]The drive has a mains transformer with a 130 °C thermal fuse in its primary, a T1A fuse, a slide switch on the rear and a line filter. The power board produces 12 V from an L78N12 regulator and 5 V from two L78N05 regulators.[1] Amstrad's specification gives the drive's supply as 240 V AC 50 Hz; the user instructions say 220–240 V 50 Hz and ask for a 3 A fuse in a 13 A plug.[1][2] The maintenance guide has the regulator voltages and capacitor values.
Setting up and use
[edit | edit source]Amstrad's user instructions give these rules:[2]
- Plug the interface into the edge connector marked FLOPPY DISC on the rear of the CPC 464 with everything switched off. The connector at the end of the ribbon cable goes to drive A; the one part way along is for a second drive, the FD-1.
- Switch the disc drive on before the computer.
- Remove any disc before switching the system on or off, and do not press the eject button while the drive is reading or writing.
- Keep the drives at least 20 cm from the monitor, away from magnetic fields, and keep the ribbon cable away from mains leads.
- Use Amsoft CF-2 discs for best reliability.
The interface takes 1,280 bytes of the CPC 464's memory, so some cassette software fails with it fitted; Amstrad's remedy is to switch off and unplug the interface.[2] If the computer shows "Press PLAY then any key" when a disc command is expected, the drive or interface is not connected or the drive is not switched on.[2]
The red indicator lamp shows reading or writing. With two drives connected, the lamp on drive B stays lit to identify it and goes back to showing activity when that drive reads or writes.[2]
Repair
[edit | edit source]The Amstrad DDI-1 Maintenance Guide covers the power supply, the drive belt and spindle speed, the alignment checks and Amstrad's fault-finding charts. Amstrad told its service agents not to repair or adjust the mechanism or its control board (PCB 30001) during the warranty period; faulty mechanisms went back to Amstrad for exchange, and no parts were listed for PCB 30001.[1]
The Amstrad CPC 664 and Amstrad 6128 have built-in 3-inch drives, covered in their own service manuals. See also Floppy Drive Repair.
Documentation
[edit | edit source]- Amstrad DDI-1 / FD-1 Service Manual – Amstrad's service manual for the DDI-1 and FD-1
- Amstrad DDI-1 User Instructions – retyped edition of the 1984 user instructions
Related pages
[edit | edit source]- Amstrad DDI-1 Maintenance Guide
- Amstrad CPC 464 · Amstrad CPC 464 Maintenance Guide
- Amstrad MP-1 – the modulator and power supply for using a CPC 464 with a television
- Floppy Drive Repair
References
[edit | edit source]- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Amstrad Consumer Electronics plc, DDI1 / FD1 Service Manual. Hosted as File:Amstrad DDI-1 FD-1 Service Manual.pdf, described at Amstrad DDI-1 / FD-1 Service Manual. Specification and safety test p. 2; cabinet drawing and parts list p. 3; software errors p. 4; diagnostic flow chart pp. 5–8; circuit diagram pp. 12–13; electrical parts list p. 14; alignment checks pp. 16–19; mechanism p. 20.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Amstrad Consumer Electronics plc (AMSOFT), Disc Drive & Interface DDI-1 user instructions, © 1984, retyped edition. Hosted as File:Amstrad DDI-1 User Instructions.pdf, described at Amstrad DDI-1 User Instructions. Foundation course sections F1.1–F1.4 (setting up), F2 (discs, indicator lamp), F3.2 (memory usage warning), F4.11 (summary); section 2.7 (AMSDOS error messages); section 5.4 (BIOS error messages).