Re: PLA equations for the 1551 drive's cart

I have the JED files for this which I got from Ian Gledhill some years 
back. I had just acquired a TopMAX programmer and some blank 82S100's, 
but never got round to testing them. (Another unfinished project !)

Ian also told me that some of the terms need to be swapped for the 
TopMAX, but never really figured out what that meant. I'll mail you the 
files and if they help, great! Would love to know how you get on.

Rob

On 21/02/2025 11:30, Francesco Messineo wrote:
> nevermind, I figured out they just used the standard 82S100
> input/output names so I could get the correct pin numbers for the CUPL
> source file.
> I'll post the resulting files once verified.
>
> On Fri, Feb 21, 2025 at 10:17 AM Francesco Messineo
> <francesco.messineo_at_gmail.com> wrote:
>> Hi all,
>> I need to program a replacement PLA for a 1551 drive, of course I have
>> blank ICs. Now, the only equations I've found are these:
>> https://www.zimmers.net/anonftp/pub/cbm/firmware/drives/new/1551/1551.251641-3.c
>> Pin numbers are not present and it references a mapping but I haven't
>> really found that one.
>> It seems to me the code uses the address and bus bits of a 27512 but
>> I'm not really sure.
>> PLS100 ICs can be programmed only once, before I try wasting a lot of
>> them, does anyone have the equations in form of pin number or pin
>> names according to the schematic? Or does have a reliable mapping for
>> that C file to actual 82S100 pin numbers?
>> Of course i'll post the working jedec file once verified.
>> Thanks in advance
>> Frank IZ8DWF