TTL computing

From: Ben Franchuk <>
Date: Sun Apr 14 10:00:50 2002

Richard Erlacher wrote:

> If you buy a moderately cheap CPLD, e.g. the XILINX 95108, in a PLCC84, it
> costs about $20-30 U.S. at DigiKey. Combine that with a socket, ($4 tops) and
> a few wirewrap socket pins, ($.10 each) that's another $8.40. Now find a
> cheap wirewrap board to which you can solder ... and then use the free
> software and build the ~$5 ISP adapter.
Has anybody done that?

> For the same money, you can use a
> Xilinx SPARTAN-series FPGA which you can also program using the ISP
> programmer, though you'll have to do it every time. Then you can design
> pretty much whatever small computer (only because of pin-count limitations)
> you want. These devices even allow you to put in some RAM.
I have a nice FPGA prototype kit, (altera) but I am having problems
getting A PROM for it. I may go to using smaller chips like the XC-9572
(72 macro cells) ? $12 canadian. They don't make wire wrap PLCC sockets
(or not in DigiKey) so I will end up with making a PCB. I have a new CPU
design and expect about 10 CPLD's in total.
Ben Franchuk - Dawn * 12/24 bit cpu *
Received on Sun Apr 14 2002 - 10:00:50 BST

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