RE: Exorcisor on a chip

On Mon, 23 Feb 1998, Ozdemir, Steve wrote:

> G'day Joe,
>
> Cool...I was considering this for a FPGA project, but your PLD
> implementation of the project seems much more appropriate. Have you
> tested it out to see if you can locate a fault (and fix it)? You might
> want to get some experience at this before remanufacturing this. Sorta
> work out any last kinks...

        No, I haven't actually fixed a board with it yet. The way I
determined that it works is by looking at the signatures of the Exorcisor
that Dave Fish put on his schematic of the Exorcisor. I compared each
signature to the outputs of my Exorcisor PLD, and they all matched. So,
I'm 100% sure that the PLD works fine. I also tapped the clock for the
Exorcisor right off of a Cine. CPU board and designed my own "clock
terminator" (OK, well it's just a Schmitt trigger) because Dave F. had
said that he was having problems with his clock.
 
> > If you have a shortage of broken Cinematronics motherboards, I'm sure
> some folks on this list might have some they'd be willing to let you
> practice on. Heck, they might end up with working boards after your
> experimentation, eh? My hat's off to both you and David Fish for making
> this remanufacturing of the Cinematronics Exercisor possible!

        No problems in that area -- I have PLENTY of broken Cine. CPU
boards!

> ps - If your price is cheap enough, I'd buy one just as a back up. Do
> you have an idea of what it'll cost? $50?? $100??? Is it possible to
> solder directly to a socket and forgo the PCB....I'm envisioning a hack
> job where you use long wiring harnesses and gather them up close to the
> socket with several wireties. Then encase the whole thing in electrical
> tape (maybe adding something to give structure to the bundle of wires
> and the actual chip...well, that'd be just like a PCB right? 8^) 8^)
> 8^)).
>

        The problem is that this thing is a 44-pin PLCC package. To mount
it to a PCB, it gets put into a sort of PLCC to PGA socket, and the pins
are spaced pretty close together, so it's very hard to solder individual
wires to them. In this prototype version, I bought a breadboard which has
a PLCC socket mounted to it from my local electronics store, and I was
able to breadboard a design.

Joe
Received on Mon Feb 23 09:44:07 1998