14 Jan
2004
14 Jan
'04
5:46 p.m.
At 03:31 PM 1/14/2004 -0800, you wrote:
OK, using a 1 million gate FPGA to replace a 7400 is
overkill, but it would work
--
Not if the FPGA isn't 5v tolerant.
It isn't very likely that a device produced in five years
will be useful as a replacement for 7400 series logic, much
less in 50.
We've left the days of logic level compatibility behind us
unfortunately. 3.3v logic is even disappearing pretty quickly
now, and that didn't last a decade.
I am having problems getting enough information to make my Emulex
SC70 masbus disk controller work. If I have to repair it, I'm will
be in serious trouble. I doubt that I will be able to locate a
schematic given that I am having so much difficulty locating just
a manual. The SC70 uses a 16bit 290x bitslice processor, so after
those parts are no longer available, even though it would trivially
fit into a small FPGA of the time, and even if the logic levels are
compatible, reprogramming an FPGA to do what the 290x does will not
be a trivial task.
Just imagine trying to repair all of the proprietary components
in a PC or even the CAD program dongle 50 years from now.