An essential piece of kit for creating your own ROMs
I needed an EPROM programmer to create (called “burning”) my own ROM efforts in silicon, but I could not afford to buy any that were available. They are still very expensive pieces of equipment!
I then found a serial EPROM programmer project in an electronics magazine called ETI. This EPROM programmer was different from all the others I had looked at because it was a dumb device that could be linked to any host computer via an RS232 serial port. All the work and cleverness of the programmer was actually done in the software running on the host computer.
I thought I could build this EPROM programmer and write suitable software for the CPC... So I did!
I ordered a ready-made PCB from the magazine and all the bits from Maplins. I then set to work with my soldering iron, and after a couple of nights I had all the components on the PCB. After another few nights I had it in a nice plastic box with labels I drew with Micro-Design.
From start to finish I followed the instructions in the article, with one exception. I decided to add a 500mA fuse in line with the 9v power input socket - I knew from experience that faulty EPROMs often go short-circuit across the power rails. This modification has saved me many times!
I needed some software to drive the Programmer with the CPC, so I wrote my own. It is a BASIC and Z80 machine code combination - essentially the Menu interface is written in BASIC, with all the clever stuff in Machine Code. It relies upon the CommStar RS232 interface and suppoprt ROMs too.
After doing a quick google search I actually found that this Serial EPROM Programmer project is now on-line!
Now for some bad news. All my work for this project is still on 3” CPC disks.
1. Scan the original ETI article and put it here.
2. Post screen shots of my software.
3. Dig out all my CPC disks and put them here.
4. Finish off development of the software I wrote...
5. Remove the need for the Commstar ROMs...
My Serial EPROM Programmer:
Ian Neill, 08/07/04, re-edited 15/10/06.