Re: PLA equations for the 1551 drive's cart

From: Francesco Messineo <*francesco.messineo_at_gmail.com*> Date: Fri, 21 Feb 2025 11:30:44 +0100 Message-ID: <CAESs-_w6TOa-_R_EohwFYPoswreTKZi6EXymOv=fe1D5rG0b-w_at_mail.gmail.com> · francesco.messineo_at_gmail.com

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