Reply 21540 of 22050, by scruit
Last night I built an tested a Dramarduino from these instructions. https://forum.defence-force.org/viewtopic.php?t=1699
Found the arduino code has a bug (I use the version from this post specifically https://forum.defence-force.org/viewtopic.php?p=26686#p26686) The bug is thatthe arduino code makes use of nointerrupt mode for faster processing of the memory testing cycles, but between tests it issues a "delay(1000)" (within the blink() function) while still in noninterrupt mode, so the test hangs waiting for the delay to come back, which it will never do. I fixed my copy of the code and I'm registering there to give feedback (or find out if there is a github for it these days)
This tester is stated to work with 4164 and 41256 chip for vintage computers. I have around 64 of M5M4257 memory chips that are compatible with 41256 and the first couple tested fine.
This morning I'm upgrading the protoboard with a 1602 I2c screen, ZIF socket and 3d-printed case. All this will make it more user-friendly for testing all of the chips. I'm also going to see if I can use it to test the external cache ram chips. "To the datasheets!!"