syzygy
Experienced Member
I have programmed and used lots of 'modern' serial EEPROMs, but as far as I can remember, I have never programmed an 'old school' EPROM, but I always wanted to learn about them and use them. I remember marveling at those magazine projects about building your own EPROM programmer. Alas, I never did that. But I bought myself one for xmas and I have been figuring it out over the last couple of days. Once, I figured out how to get it to recognize the old XP parallel port, things began to come together.
Many years ago, I somehow managed to receive an old and stripped down Dataerase II and actually found it and it still works. So, tonight, I erased 27C256 and a 2716. They now read as all FF and pass the blank test. I also programmed a 2732 and an old Intel 2716 (25V) after erasing them. BTW both 2716s took a *long* time to erase. I used the .hex file from this project, which I am considering undertaking because it looks like cheap fun.
The chips look like they programmed fine and they read back what they are supposed to- of course I haven't actually used them, but so far so good.
I actually managed to find 7-8 other EPROMS that I squirreled away over the years.
One of the 2716s came in this socket...
If I am reading the datasheet right, this socket, with the heat-resistant tape, connects GND to CE (so it is always on), and Vcc to Vpp, which the data sheet says is fine, except that it is rather rather inconvenient if you want to program it. I was able to remove the socket and reclaim the chip proper.
I am actually pretty impressed by this Willem programmer. You have to check/set a lot of stuff and make sure you find the right data sheet (e.g., the Intel 2716 has Vpp=25v and the Thomson 12.5V). That may be old history to some of you folks, but not to me.
Anyways, it works! Cool stuff.
Many years ago, I somehow managed to receive an old and stripped down Dataerase II and actually found it and it still works. So, tonight, I erased 27C256 and a 2716. They now read as all FF and pass the blank test. I also programmed a 2732 and an old Intel 2716 (25V) after erasing them. BTW both 2716s took a *long* time to erase. I used the .hex file from this project, which I am considering undertaking because it looks like cheap fun.
The chips look like they programmed fine and they read back what they are supposed to- of course I haven't actually used them, but so far so good.
I actually managed to find 7-8 other EPROMS that I squirreled away over the years.
One of the 2716s came in this socket...
If I am reading the datasheet right, this socket, with the heat-resistant tape, connects GND to CE (so it is always on), and Vcc to Vpp, which the data sheet says is fine, except that it is rather rather inconvenient if you want to program it. I was able to remove the socket and reclaim the chip proper.
I am actually pretty impressed by this Willem programmer. You have to check/set a lot of stuff and make sure you find the right data sheet (e.g., the Intel 2716 has Vpp=25v and the Thomson 12.5V). That may be old history to some of you folks, but not to me.
Anyways, it works! Cool stuff.