Re: Blank CMS SCSI Card PCBs

[r_beaudry@hotmail.com (Rich Beaudry)]

david@uow.edu.au (David Wilson) wrote in message news:<3ca81344$1@news.uow.edu.au>...

> 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.

Thanks for the link!  I will follow up with them to determine package
type, and minimum order quantities...

> 
> 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.

Let me preface this by saying that I am a *total* newbie to
programmable logic, but the way I understood PALs is that you don't
necessarily know what is an output, and what is an input.  You may
know that there's a max of, for example, 8 inputs, but you don't know
where (what pins) they are....  It may not be impossible to decipher,
but I didn't think it was that easy ... Otherwise, why have a security
bit??

Don't get me wrong, I HOPE it's that easy, but I didn't think it
was....

Also, if you are interested in a blank board or two, please email me
OFF-LIST your address, and they wil be sent to you....

Rich B.