Hi!

I want to build a universal programmer which programs E(E)PROMs, PLDs,
Microcontrollers, etc... and the sort of devices the commercial ones
program. I couldn't figure out the base idea yet. I want to build at
least a 40 pin (48) device. I think it would be great to build it
maximally flexible programmer, so on all the 40 (48) pins it could
 switch the Programming voltage (which is adjustable from software), the
Vcc (also adjustable), a bidirectional digital I/O, and GND if neccesary.
This leads to a quite complicated hardware. But with special ICs these
functions could be accomplished with very few parts. I have 5-7 ideas
on the pin circuit (ie. the circuit which connects to all the pins), but
all have drawbacks (generally 4 or 5 functions go well, but adding an
extra switching option requires much more resources. I was considering
analog multiplexers, but there's a problem with the maximum current. I
have though of using AllegroMicro devices. How could I switch the GND
without the need of Relays?
Any help would be appreciated.
Thanks: cotan