DIY:Floppy Drives

Preface

This document shows pinning list, wiring diagrams and signal descriptions found on a CPC6128.

Multi-Adaptor Cable for External Floppies / HxC emulator

Adaptor Cable for Internal Floppies / HxC emulator

This cable assumes that the drive has been set to DS0 / ID0 and provides a ready signal. For the HxC not a problem, just a simple jumper setting, for floppies this may involve making some mods to the drive.

I've shown the cable from several views to highlight the fact that the connectors don't face the same way on the cable.

First crimp the 26way connector as shown in the diagram. Then split the first 6 wires starting from the side of the red wire. These 6 wires need to be shifted 2 cavities further over before being crimped into the 36way connector. Wire 26 goes directly to pin 34 of the floppy connector. Make sure the keyways / orientation slots of both connectors are as shown in the diagram. The cable needs no bridges, switches or anything else. When you are finished, you should have a cable looking something like this:

Signal assignment on connectors

Standard floppy connector 34pin

Floppy connector	Signal description
1..33	GND	Ground
2	/DCD	Disk Change Detect
4	/DS3	Drive select 3 (Not always supported)
6	/INUSE	Open collector LED driver
8	/IND	Index
10	/DS0	Drive select 0
12	/DS1	Drive select 1
14	/DS2	Drive select 2
16	/MTRON	Motor enable
18	/DIR	Direction select
20	/STEP	Head step
22	/WDAT	Write data
24	/WGAT	Write gate
26	/TRK0	Track 0
28	/WPT	Write protect
30	/RDAT	Read data
32	/S1	Side select
34	/RDY	Ready/Disk change depending on drive configuration

CPC-CD201 (internal floppy 26pin connector)

CPC-CD201	Signal description (numbering from Amstrads repair manual)
1..25	GND	Ground
2	/IND	Index
4	/DRV1	Drive select 1
6	NC
8	/MED1	Motor enable drive 1
10	/DIR	Direction select
12	/STEP	Head step
14	/WDAT	Write data
16	/WGAT	Write gate
18	/TRK0	Track 0
20	/WPT	Write protect
22	/RDAT	Read data
24	/S1	Side 1 select
26	/RDY	Ready (or /DSKCHG) depending on model or drive configuration

CPC-PL-9 (external floppy 34pin centronics connector)

CPC-PL-9	Signal description external (numbering from Amstrads repair manual)
2..34	GND	Ground
33	+5V
31	+5V
29	+5V
27	/IND	Index
25	NC
23	/DRV1	Drive select 1
21	+5V
19	/MED1	Motor enable drive 1
17	/DIR	Direction select
15	/STEP	Head step
13	/WDAT	Write data
11	/WGAT	Write gate
9	/TRK0	Track 0
7	/WPT	Write protect
5	/RDAT	Read data
3	/S1	Side 1 select
1	/RDY	Ready (or /DSKCHG) depending on model or drive configuration

Pinning translation between different connectors (CPC-PL-9, Centronics 36pin, Floppy connector 34pin)

Translation from CPC-PL-9 via Centronics 36 pin connector to floppy connector 34pin
===================================================================================
(flat cable / crimp variant view)

                          +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---- GND
                          |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
Floppy connector 34pin   33  31  29  27  25  23  21  19  17  15  13  11  09  07  05  03  01  NC
Centronics 36pin         18  17  16  15  14  13  12  11  10  09  08  07  06  05  04  03  02  01 
Amstard CPC-PL-9         02  04  06  08  10  12  14  16  18  20  22  24  26  28  30  32  34  NC
                       **++**++**++**++**++**++**++**++**++**++**++**++**++**++**++**++**++**++
Amstard CPC-PL-9       01  03  05  07  09  11  13  15  17  19  21  23  25  27  29  31  33  NC 
Centronics 36pin       36  35  34  33  32  31  30  29  28  27  26  25  24  23  22  21  20  19 
Floppy connector 34pin 34  32  30  28  26  24  22  20  18  16  14  12  10  08  06  04  02  NC
                        |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
                        |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   +-- NC
                        |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   +------ +5V
                        |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   +---------- +5V
                        |   |   |   |   |   |   |   |   |   |   |   |   |   |   +-------------- +5V
                        |   |   |   |   |   |   |   |   |   |   |   |   |   +------------------ /IND
                        |   |   |   |   |   |   |   |   |   |   |   |   +---------------------- NC
                        |   |   |   |   |   |   |   |   |   |   |   +-------------------------- /DRV1
                        |   |   |   |   |   |   |   |   |   |   +------------------------------ +5V
                        |   |   |   |   |   |   |   |   |   +---------------------------------- /MED1
                        |   |   |   |   |   |   |   |   +-------------------------------------- /DIR
                        |   |   |   |   |   |   |   +------------------------------------------ /STEP
                        |   |   |   |   |   |   +---------------------------------------------- /WDAT
                        |   |   |   |   |   +-------------------------------------------------- /WGAT
                        |   |   |   |   +------------------------------------------------------ /TRK0
                        |   |   |   +---------------------------------------------------------- /WPT
                        |   |   +-------------------------------------------------------------- /RDAT
                        |   +------------------------------------------------------------------ /S1
                        +---------------------------------------------------------------------- /RDY

**/++ Flatcable signal

Wiring diagrams

External floppy connector CPC-PL-9 to standard floppy connector 34pin

(flat cable / crimp variant view)

Note: Disconnect wire 03-35-32 /S1 if you use a side selector switch which is connected to the floppy drive.

PL-9	CEN	PCF	SIGNAL
01	36	34	/RDY
02	18	33	GND
03	35	32	/S1
04	17	31	GND
05	34	30	/RDAT
06	16	29	GND
07	33	28	/WPT
08	15	27	GND
09	32	26	/TRK0
10	14	25	GND
11	31	24	/WGAT
12	13	23	GND
13	30	22	/WDAT
14	12	21	GND
15	29	20	/STEP
16	10	19	GND
17	28	18	/DIR
18	10	17	GND
19	27	16	/MED1
20	09	15	GND
21	26	14	NC
22	08	13	GND
23	25	12	/DRV1
24	07	11	GND
25	24	10	NC
26	06	09	GND
27	23	08	/IND
28	05	07	GND
29	22	06	NC
30	04	05	GND
31	21	04	NC
32	03	03	GND
33	20	02	NC
34	02	01	GND
	19		NC
	01		NC

Internal floppy connector CD201 to standard floppy connector 34pin

(flat cable / crimp variant view)

Note: Disconnect wire 24-32 /S1 if you use a side selector switch which is connected to the floppy drive.

CD201	PCF	SIGNAL
26	34	/RDY
25	33	GND
24	32	/S1
23	31	GND
22	30	/RDAT
21	29	GND
20	28	/WPT
19	27	GND
18	26	/TRK0
17	25	GND
16	24	/WGAT
15	23	GND
14	22	/WDAT
13	21	GND
12	20	/STEP
11	19	GND
10	18	/DIR
09	17	GND
08	16	/MED1
07	15	GND
06	14	NC
05	13	GND
04	12	/DRV1
	11	GND
	10	NC
03	09	GND
02	08	/IND
01	07	GND
	06	NC
	05	NC
	04	NC
	03	NC
	02	NC
	01	NC

Issues

Floppy drive

• This cables work for drive which are jumpered as drive 1/DS1. This is normally the default selection on drive delivery.
• Make sure you find a drive which has the possibility to generate a ready signal instead of a disc change signal.

Disk issues

If you think about to use a HD drive, make sure to close the HD detection hole on your disk. </pre>