3??�?" & 5??�?" Disk Drives

Besides the "big" brands' disk drives for the Amstrad CPC, there were also user solutions and garage company made disk drives for the Amstrad CPC.

These usually came without their own DOS, or you had to replace the built-in AMSDOS with a DOS like ParaDOS or a patched AMSDOS.

But even without a special DOS taking use of the higher capacity of those drives, the use of such drives made sense, as media were much cheaper than 3" media.

Today, with supplies of 3" disks draining and company solutions no longer being produced, a self-made 3 1/2" disk drive is the perfect supplement for every CPC user.

Notes

• Whereever possible, the wire numbers from the PC standard were used!

• The universal solution connects a 3" or 3 1/2" disk drive to any CPC with disk controller
  • You can even use Part A for connecting a 3" disk drive to a CPC664/CPC6128/CPC6128plus and Part Bx for connecting a 3 1/2" disk drive to a CPC464 with DDI-1 at the same time
  • Part Bx, which is also the full cable for the CPC464 with DDI-1, can even be used to connect the PC drive as A: on the DDI-1, though this doesn't work with all drives.

• Although schematics for drives without own RDY-Signal are given, it is highly recommended to use drives with RDY to ensure maximum compatibility. The only todays drive known to be resolderable to output a RDY-signal is the Samsung SFD-321B and many drives won't work as A: on the CPC464+DDI-1 without a permanent RDY though.

• These schematics differ from most existing schematics on the web in that way, that they don't use GND to pull signals active low, but the /DRIVE SELECT line via diode. This ensures that the other drive on the bus doesn't become influenced. You can solder the wire containing the diode directly (without the diode) to a GND-wire and you will get the same as described in other tutorials but the side switch and - if applicable - the permanent RDY will also be in effect for the other disk drive then.

• Hints for fitting cut/squeeze plugs on flat-ribbon cable (Assuming you were building the cable according to the PC wire numbers with red wire = wire 1), connectors seen from back:
  • Amstrad CPC664/CPC6128: Red wire showing away from orientation nose inside the connector
  • Schneider CPC6128 (DE): Red wire showing to the right with two free pins on the right end of the connector
  • Amstrad CPC6128plus: Red wire showing to the right with three unused pins on the left end of the connector (red wire not connected/overlapping end of connector)

Schematics

Universal solution (CPC464+DDI-1, CPC664, CPC6128, CPC6128 German and CPC6128plus)

Part A: Replacement cable for original Amstrad/Schneider FD-1

Identical to the cable for the FD-1 except that it is for the CPC664, CPC6128 and CPC6128plus at the same time

Part B1: Makes a PC disk drive with RDY behave like a DDI-1

Makes a PC disk drive with RDY behave like a DDI-1

Part B2: Makes a PC disk drive without RDY behave like a DDI-1

Makes a PC disk drive without RDY behave like a DDI-1

Amstrad/Schneider CPC464 with DDI-1

See Part B1 or Part B2 as shown in sections 2.1.2 or 2.1.3 accordingly.

Amstrad/Schneider CPC664/CPC6128 (Not German CPC6128s!)

Drive has RDY-signal

Schematics for PC disk drives with own READY signal on an Amstrad/Schneider CPC664/CPC6128 (Non-German CPC6128 only)

Drive doesn't have RDY-signal

Schematics for PC disk drives without own READY signal on an Amstrad/Schneider CPC664/CPC6128 (Non-German CPC6128 only)

Schneider/Amstrad CPC6128 (German models and grey imports from Germany only!)

Drive has RDY-signal

Schematics for PC disk drives with own READY signal on a Schneider CPC6128 or a German Amstrad CPC6128

Drive doesn't have RDY-signal

Schematics for PC disk drives without own READY signal on a Schneider CPC6128 or a German Amstrad CPC6128

Amstrad CPC6128plus

Drive has RDY-signal

Schematics for PC disk drives with own READY signal on an Amstrad CPC6128plus

Drive doesn't have RDY-signal

Schematics for PC disk drives without own READY signal on an Amstrad CPC6128plus

Garage companies that sold disc drives

• Frank Straus 5 1/4" Drive
• G+L Electronic (3 1/2" and 5 1/4" disk drives)