I had a horrible time getting this otherwise really simply board working and I'm still not entirely sure what fixed it. It got to the point where I reproduced the board in prototype form on a breadboard and I could communicate with the IO device but for whatever reason I couldn't do the same on the board. I tried cleaning the board, swapping chips, checking power, checking signals, checking for shorts - everything seemed fine but it just wouldn't work. I then took out the chip select signal from the board by soldering a wire to appropriate GAL pin and used it to select the prototype version (rather than using the prototype GAL) and it still didn't work ... I was just about to give up and so desoldered the chip select wire ... and then it started to work - I have no idea why
Anyway, the first prototype of the IDE interface appears to be running with RomWBW and the Z80 board (it is based on the RC2014 equivalent). I tested it with a compact FLASH to IDE adapter, the FLASH card has the RomWBW "combo" disk image. I tested booting CP/M 3 off it and that seemed to work OK. I wanted to have a right-angle IDE header so that I could plug the FLASH adapter on top (so it doesn't interfere with other cards when it is in the upright position) but it turns out that I had the connector the wrong way around - it didn't really matter as the IDE adapter doesn't have a guide on top (like the right-angle header has) - but it does have a "key" i.e. blocked pin in the socket to ensure the adapter is plugged in the right way around. I think the PCB-mount LEDs I purchased may also be the wrong way around compared to what I expected so the activity light on the board isn't lighting up (though activity is still shown on the FLASH card adapter). I haven't tested the standard 40-pin IDE yet. I may need another adapter to test that as I don't have any IDE drives.
The one bit I haven't tested yet is the 40-pin IDE interface. It "should" be identical to the 44-pin interface apart from missing the power lines (those are supplied via a separate power cable).
OK, managed to check the 40-pin interface as well (I had a Compact FLASH interface on an old 486 PC that had the 40-pin adapter ... I just had to make an appropriate power cable for it). I had never previously noticed that this cable also had pin 20 blocked (to act as a key - despite having the guide on the connector) - so I had to break it off on the PCB mounted connector. I've slightly modified the PCB to add a label to point this out and have also mentioned it on the GitHub readme. I've forgotten exactly how the IDE interfaces work but I suspect that only one of the connectors should be used at any time and then the master/slave set-up needs to be used to select which drive is which (but I could be wrong).
Not the most beautiful set up ... but finally managed to test two IDE drives connected to the same card. In this instance I had a Compact FLASH to 44-pin IDE adapter board (set up as a slave) and a Compact FLASH to 40 pin IDE drive adapter (set up as a master). I can't imagine ever needing so many drives but at least it can be demonstrated to work.
