Note that the drive also powered the DDI-1 interface when used together with it. Certain pins documented as N/C in the CPC664/CPC6128 manual in fact carry +5V from the drive to the controller.
The main reason for this was that you couldn't connect a standard drive with a more common format (5¼" in the beginning, 3½" later and today) and thus cheaper disks as drive A: without modifications, as the DDI-1 wouldn't work without the power fed from the FD-1.
Details on [[AMSDOS]], Amstrad's implementation of [[CP/M]] can be found in [[Soft158A:_DDI-1_Firmware_-_The_Complete_CPC_464_DOS_ROM_Specification|DDI-1 Firmware SOFT158A]].
== Pictures ==
Image:Amstrad Computer User8504 044.jpg|Advert (ACU Apr 1985)
Image:DDI-1_cable.jpg| DDI-1 cable pinout
Image:DDI-1.jpg|DDI-1 - complete with manual, interface, FD-1 drive & CF-2 discs
</gallery>