3.5" Floppy drive using DDI-1

[geebus]

Hi all, I've added a 3.5" floppy drive to my 6128 rather easily and i'm now looking to connect one to my newly acquired DDI-1 so that i can use my discs on the 464's too.
I've done a fair amount of googling and looking over the DIY segments on the wiki. Quite useful and i'm sure i could do it. However, Me being me I want to understand exactly what is going on and then make something for myself.

I was hoping that someone could confirm or correct the pinouts for the two different systems (PC vs DDI-1) before I make up a test board.
Here's what I have.

Code Select Expand


PC DDI-1

1 GND 1 RDY
2 Density Select (1=low/0=High) 2 GND
3 GND 3 Side select
4 NC/Drive select 4 4 GND
5 GND 5 Read data
6 NC/ LED driver 6 GND
7 GND 7 Write protect
8 0= Index 8 GND
9 GND 9 Track 00
10 0= Enable motor A 10 GND
11 GND 11 Write gate
12 Drive select B 12 GND
13 GND 13 write data
14 Drive Select A 14 GND
15 GND 15 Step
16 0= Motor Enable B 16 GND
17 GND 17 Direction
18 0= Direction (stepper motor) 18 GND
19 GND 19 motor on
20 0= Step pulse 20 GND
21 GND 21 +5v
22 Write data 22 GND
23 GND 23 Drive select 1
24 Write enable, 0= Write gate 24 GND
25 GND 25 Drive select 0
26 0= Track 0 26 GND
27 GND 27 Index
28 0= Write Protect 28 GND
29 GND 29 +5v
30 Read Data 30 GND
31 GND 31 +5v
32 0=Select Head 32 GND
33 GND 33 +5v
34 1= disk change/ 0= Ready 34 GND



As always, Any help is appreciated.

[Audronic]

@geebus


Have look here :-


www.cpcwiki.eu/index.php/DDI_Modification


Ray

[geebus]

Thanks, That is exactly where I was looking before.I'm just wanting to make sure I'm not missing any pins out/got them in the wrong order.After having a further look at it, I don't think it's going to be too difficult.Hoping that if there were any big mistakes, someone with more prior knowledge would point it out to me.

[VintageAdvantage]

Right. The most important thing is to get the 5V power supply removed from the cable. After that, the thing is "cold" and nothing can get damaged any more, even if you make mistakes in wiring it up. That's the good thing about standard floppy cables - no "hot" (power) lines. Not sure what Amstrad was thinking there. Adding power to the cable is a bad idea.

[Bryce]

As long as you don't connect a 5V rail directly to GND nothing can go wrong. All other inputs/outputs will survive both 5V and GND being connected to them, so even if you connect it wrong, you won't break anything, it just won't work.

Bryce.

[geebus]

thanks all, I've got the 5v lines going elsewhere in my drawings. so I shouldn't be accidentally sending it into the drive.
Glad no one has pointed out anything wrong with what i think the lines are for haha!