HP 85B FPGA

[davorin]

Hello

I've seen here in a post from 2010 that Oliver had successfully implemented the HP 85B in Xilinx FPGA....on his site though only design files for the 86/87 models are implemented...

Someone seen the Verilog files for the 85B model or even got it running?

Reason for asking is that I've just ordered a HP-85B as my christmas present to extend my poor collection of HP-67/97 and 41 (o;

[Dave Frederickson]

The 85B doesn't run on an FPGA, so I don't see the connection. You might, however, be interested in a PRM-85 module which would allow you to run the service ROM.

As you probably know, the printer belts and the tape drive capstan are prone to deterioration. Should they need to be replaced I can recommend Larry Atherton's service.

Dave

[davorin]

Hmm....

https://sites.google.com/site/olivier2sm...fpga-hp85b

[Dave Frederickson]

Coincidentally I visited that webpage yesterday from a link in another post. That is an FPGA emulating the 85B. While the FPGA can emulate the 85B hardware and run the original ROM code, it doesn't contradict my statement that the 85B itself doesn't run on an FPGA.

So if you're getting a real 85B for Xmas, why the interest in the Verilog code for the emulator? I'm curious because I have a Spartan-3E board doing nothing and have never had an interest in recreating Oliver's emulator.

Dave

[davorin]

Well...I'm collecting some old hardware and from time to time I rebuild them into FPGA (o;

Okay...ZX Spectrum was a piece of cake...even have a PCB design lying around somewhere...also a PacMan board based on EP1C3T100.

And as I have some spare FPGA eval boards (never had Xilinx, only Altera and Lattice ;o) this would be a good excersize on the two weeks vacation...

Maybe there's some more time for the HP-97 as well...

It is alsways good to have a real hardware for comparison and hook it up to my logic analyzer (which is of crouse a HP as well ;o).