Eprom Emulator for HP-71b

[Dave Frederickson]

(09-27-2020 03:45 PM)avrkris Wrote:  Hi Dave, it's true that I focus a lot on the update process for EPROMs and the fact they have to be UV erased. The issue is not really the time it takes to erase (7 min vs 20min), its the fact that for each "update" you have to go through a "manual" process of: 1. extract your eprom from device, 2. UV erase, 3. re-install EPROM. I'm not that familiar with the HP-71b, so not sure how oftern you have to update / swap the EPROM content, but for other systems based on EPROMs, where you might be doing firmware development or frequent code changes (silly example could be game cartrige in a commodore, or ECU computer in a car, EPROM emulator saves you the entire hassle, you just plug it to a computer and you can have new version of EPROM in seconds without removing or swapping anything. I was working on a small single-board computer based on Z80 and the only way to update the firmware or write code for it, was to juggle the EPROMs but now I'm happy to use my new emulator.

Thanks
Kris (MyGeekyHobby.com)

Hi Kris,

I acknowledge that your EPROM Emulator is a nifty idea in the right application, but the 71B is not it. Most folks configure their machine once and be done with it. For experimentation the 71B software emulators do a fine job, then an EPROM can be burned. It's a similar method for the front-port EPROM's but I admit they're easier to swap.

I see your emulator on eBay in both kit and preassembled form. Nice.

Dave