Ok, so if I am right that only pins 13 to 18 need to be checked to find out if they are output or input, then this is what I have:
Pin
13 - Goes to the base of a BC238B Transistor (so is an Output).
14 - Goes to the EXTINT connection on the expansion slot connector (so is an Output).
15 - Goes to pin 18 of a 74LS244, which is an output on the 74LS244 (so is an Input).
16 - Goes to pin 19 of the same 74LS244, which is 'enable' (so is an Output).
17 - Goes to pin 9 of a 74HCT164, which is 'clear' (so is an Output).
18 - Goes to pin 20 of the 27128 EPROM, which is 'enable' (so is an Output).
Does that all look correct?
Sandy Keyboard Interface, appeal
- Chr$
- QL Wafer Drive
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Re: Sandy Keyboard Interface, appeal
https://QXL.WIN
Collector of QL related computers, accessories and QL games/software.
Ask me about felt pads - I can cut them to size and they have proved excellent for mdv data recovery.
Collector of QL related computers, accessories and QL games/software.
Ask me about felt pads - I can cut them to size and they have proved excellent for mdv data recovery.
Re: Sandy Keyboard Interface, appeal
I don't know if that is correct. Sorry ![Sad :(](./images/smilies/icon_e_sad.gif)
Instead of a text description, maybe you need to create a schematic?
![Sad :(](./images/smilies/icon_e_sad.gif)
Instead of a text description, maybe you need to create a schematic?
- Chr$
- QL Wafer Drive
- Posts: 1316
- Joined: Mon May 27, 2019 10:03 am
- Location: Sachsen, Germany
- Contact:
Re: Sandy Keyboard Interface, appeal
I think it was :S
So I generated a .PDS file, following the instructions here (p210 onwards):
https://8bit-museum.de/download/chiptes ... ro_1.2.pdf
Then using PALASM I eventually generated a .JED file.
I had issues generating as PALASM presented an error: Signal IO19 cannot have more than 8 product term(s). I modified the .PDS, burnt the result to a GAL16V8, but it didn't work (QL boots with black screen, doesn't get any further).
I've attached a zip that contains the unmodified .PDS (that failed in PALASM due to more than 8 product terms for IO19), the .PDS that I modified (probably incorrectly - I shortened io19 as it was very similar to io13!) and the .JED file generated from the modified .PDS.
I'll leave that here in case anyone ever stumbles upon it or in case it's useful in the right hands, and will give up for now!
So I generated a .PDS file, following the instructions here (p210 onwards):
https://8bit-museum.de/download/chiptes ... ro_1.2.pdf
Then using PALASM I eventually generated a .JED file.
I had issues generating as PALASM presented an error: Signal IO19 cannot have more than 8 product term(s). I modified the .PDS, burnt the result to a GAL16V8, but it didn't work (QL boots with black screen, doesn't get any further).
I've attached a zip that contains the unmodified .PDS (that failed in PALASM due to more than 8 product terms for IO19), the .PDS that I modified (probably incorrectly - I shortened io19 as it was very similar to io13!) and the .JED file generated from the modified .PDS.
I'll leave that here in case anyone ever stumbles upon it or in case it's useful in the right hands, and will give up for now!
- Attachments
-
- PALGAL.zip
- (1.76 KiB) Downloaded 87 times
https://QXL.WIN
Collector of QL related computers, accessories and QL games/software.
Ask me about felt pads - I can cut them to size and they have proved excellent for mdv data recovery.
Collector of QL related computers, accessories and QL games/software.
Ask me about felt pads - I can cut them to size and they have proved excellent for mdv data recovery.