Eprom incompatibility?
Posted: Mon Nov 16, 2020 8:04 pm
Hello everyone!
I'm trying to write some eproms with the Dragon 200E data, and as I cannot rewrite for whatever reason the original 27128 eproms that came with my Dragon 200, I decided to write a couple of 27256 chips, duplicating the content just in case.
Thing is, I managed to burn them properly (at least reading them back yields the same data that was written) but they don't work at all on any Dragon board I've tried.
The original 27128 chips are one 250ns and one 300ns access time, while the 27256 are 170ns access time, which should be no problem.
So, does anyone has an idea what could be happening?
I'm trying to write some eproms with the Dragon 200E data, and as I cannot rewrite for whatever reason the original 27128 eproms that came with my Dragon 200, I decided to write a couple of 27256 chips, duplicating the content just in case.
Thing is, I managed to burn them properly (at least reading them back yields the same data that was written) but they don't work at all on any Dragon board I've tried.
The original 27128 chips are one 250ns and one 300ns access time, while the 27256 are 170ns access time, which should be no problem.
So, does anyone has an idea what could be happening?