29 Oct
2012
29 Oct
'12
10:51 a.m.
Did you/can you test your RAM?
No. The P2142 is one of that RAMs that I haven't even heard of. It seems
to be a 2114 with 4 bits. Of course, I can get some SRAM and put in its
place, or create a small tester for a quick test on protoboard.
Do you have access to a system tester like a Fluke
9010A (with an 8086
pod, as well)? Not many folks have them, but if you do or can borrow
one, they are nice for RAM tests, ROM test, bus tests, etc.
I have a 16500c with 16505a and the 8086/8088 pod. Just need to find the
software on the net and learn to use it :o) But for me it is the last
measure. The setup time is huge and I'm busy finishing a project I gotta
show this week :oP I'd like to find a faster answer :)
I don't know anything about the D3625A PROMs, but
one thing that might
be handy is to make a pin-swabber socket. It's easy for JEDEC or
near-JEDEC parts, a bit more work for oddball parts. The idea is to
provide a socket for a 2K or 4K EPROM and stuff in a 2716 or 2732
which should work fine with your Beeprog. Of course if you have a ROM
emulator, that's even easier to work with. Reading odd EPROMs is a
lot easier than writing them, so the trick here is to fit in standard
EPROMs to make it easy to put your own code on the machine.
This is the first thing I thougth. But as I said, I was looking for a
quickie. It will take some time I cannot invest today :(
The idea is to be able to write some very simple
"blink the LED"-type
programs with a small handful of instructions and watch for success
and make the programs incrementally more sophisticated so you can
first be certain that the bus and ROM work, then RAM, then I/O chips,
etc. In the early stages, you can use/make a simple logic probe or
just use an oscilloscope to watch for the "output" of your program.
Later, you would be able to spit out text via your UART, once you know
more things are working.
I have an eprom emulator, but not a 16 bit one :o(
Thanks anyway for the tips...I think I'll shelf the board, and come back
later :o)