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'''Amstrad''' made two different [[disk drives]] for the Amstrad/Schneider CPC range:
'''Amstrad''' made two different [[disk drives]] for the Amstrad/Schneider CPC range:


* DDI-1 - a set, consisting of the real DDI-1 (= Disk Drive Interface) and a FD-1 3" disk drive, as well as the CP/M 2.2 license and disk.
* DDI-1: a set consisting of the real DDI-1 (= Disk Drive Interface) and a FD-1 3" disk drive, as well as the CP/M 2.2 license and disk.


This set was for the CPC464, which doesn't have the disk controller built-in.
This set was for the CPC464 which didn't have a built-in disk controller.


* FD-1 - a 3" disk drive as secondary disk drive unit for the CPC664, CPC6128 and CPC464 with DDI-1
* FD-1: a 3" disk drive as secondary disk drive unit for the CPC664, CPC6128 and CPC464 with DDI-1


Note that there was no official external disk drive for the 6128Plus or even the 464Plus.
There was no official external disk drive for the 6128Plus or even the 464Plus. The difference between a CPC664/CPC6128 and a 6128Plus was simply a changed pin-out which can easily be solved by a new plug on the disk drive's cable.


While the difference between a CPC664/CPC6128 and a 6128Plus was simply a changed pin-out which can easily be solved by a new plug on the disk drive's cable.
The 464Plus was harder to equip with a disk drive. Although the pin-out of the expansion port was left unchanged, the DDI-1 cannot be used on the 464Plus without modifications.


The 464Plus was harder to equip with a disk drive: Although the pin-out of the expansion port was left unchanged, the DDI-1 cannot be operated on the 464Plus without modifications.
== Technical Details ==


== Technically Speaking ==
The two disk drives were identical. The only difference was that the DDI-1 shipped with controller, manual and CP/M 2.2 on one disk.


The two disk drives were identical, the only difference was that the DDI-1 shipped with controller, manual and CP/M 2.2 on one disk.
The disk drives were jumpered (more accurately, soldered) to react on both drive select lines, A: and B:.
 
The disk drives were jumpered (rather: soldered) to react on both drive selects, A: and B:.


The cable decided which drive became A: and which one became B: :
The cable decided which drive became A: and which one became B: :


* On the CPC664 and CPC6128 computers, DRIVE SELECT 0 was not wired externally, so the drive could only become drive B: on these systems.
* On the CPC664 and CPC6128 computers, DRIVE SELECT 0 was not connected on the external connector, so the drive could only become drive B: on these systems.
* For the DDI-1, DRIVE SELECT 0 was only wired to the outmost connector of the attached cable, while the inner connector was wired to DRIVE SELECT 1 only, thus the drive at the cable's end always became A: while the other one became drive B: accordingly.
* For the DDI-1, DRIVE SELECT 0 was only wired to the outermost connector of the attached cable, while the inner connector was wired to DRIVE SELECT 1 only, thus the drive at the cable's end always became A: while the other one became drive B: accordingly.


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.
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 benefit of 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 won't work without the power fed from the FD-1.
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.


== Pictures ==
== Pictures ==

Revision as of 16:51, 12 October 2009

Amstrad made two different disk drives for the Amstrad/Schneider CPC range:

  • DDI-1: a set consisting of the real DDI-1 (= Disk Drive Interface) and a FD-1 3" disk drive, as well as the CP/M 2.2 license and disk.

This set was for the CPC464 which didn't have a built-in disk controller.

  • FD-1: a 3" disk drive as secondary disk drive unit for the CPC664, CPC6128 and CPC464 with DDI-1

There was no official external disk drive for the 6128Plus or even the 464Plus. The difference between a CPC664/CPC6128 and a 6128Plus was simply a changed pin-out which can easily be solved by a new plug on the disk drive's cable.

The 464Plus was harder to equip with a disk drive. Although the pin-out of the expansion port was left unchanged, the DDI-1 cannot be used on the 464Plus without modifications.

Technical Details

The two disk drives were identical. The only difference was that the DDI-1 shipped with controller, manual and CP/M 2.2 on one disk.

The disk drives were jumpered (more accurately, soldered) to react on both drive select lines, A: and B:.

The cable decided which drive became A: and which one became B: :

  • On the CPC664 and CPC6128 computers, DRIVE SELECT 0 was not connected on the external connector, so the drive could only become drive B: on these systems.
  • For the DDI-1, DRIVE SELECT 0 was only wired to the outermost connector of the attached cable, while the inner connector was wired to DRIVE SELECT 1 only, thus the drive at the cable's end always became A: while the other one became drive B: accordingly.

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.

Pictures

Covers

Manuals

Service Manual

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