Re: Blank CMS SCSI Card PCBs

[david@uow.edu.au (David Wilson)]

r_beaudry@hotmail.com (Rich Beaudry) writes:
>The only problem (aside from a source of 5380 chips), will be the
>PALs.  I have been told the security bit is blown, so it may be
>impossible to decipher....

http://www.neiparts.net/atmbnkprnt/ncr.php seems to list NCR 5380 chips
at $9.69 each. Does not mention package type (DIP/PLCC etc). If they are the
right type it might be worth buying a batch for spares.

If the PALs are combinational (no feedback) they will be trivial to reverse
engineer (they have no flip flops). You just apply each possible input
to the 8 input pins and record the values on the 8 output pins. Then you
work out the simplest equation to generate each of the 8 outputs from the
8 inputs. Then you find the nearest equivalent (eg PALCE16V8 or GAL16V8)
and program it.
--
David Wilson  School of IT & CS, Uni of Wollongong, Australia