Thank you all for the good advice.

I constructed a prototype VGA output based on a Xilinx XC9572 CPLD, a 32kb SRAM, and three TTL buffers for bus isolation. It works rather well, the picture is stable, but I will only know whether it really displays the RAM's contents after I connected a MPU to it ...

A relatively simple technique to accelerate VM execution by -say- 20-50% is Direct Threading (see https://en.wikipedia.org/wiki/Threaded_ ... _threading). It fattens the code a bit, though.

Thank you all for the information and comments.

I ordered a TL866CS programmer from an US supplier, and will start to experiment with EEPROMs and GAL programming.

Also, I found some long lost Xilinx XC9572 CPLD's, have ordered a programmer cable, and am now trying to find adequate programming ...

Venerable folks of 6502.org,

first, let me introduce myself: My name is Oliver Ullrich, I'm a (very!) long time lurker, first time poster. I'm German, but live in Miami, Florida now. I have a bit of experience with MCS-51 and Z80 circuits, but never built anything 6502. That might change soon ...