Dwight Elvey wrote:
>
> Hi
> One method that has not been talked about too much is
> one that I've often used. It does take a prom programmer
> and an assembler helps. I often write small pieces of
> test code to check one part or another of a micro system
> and program an eprom with it. While I usually make an assembler
> for the processor I'm playing with, the code chunks are so
> small that one could easily hand assemble. ( Of course,
> if you just happen to have the right ICE or ROM-ICE, you
> don't need the programmer. Oh I wish!! )
> I usually try to find some output someplace to use as a
> trigger or if you are luck, a display of some kind. Once
> one has some kind of basic indicator ( it can be as simple
> as a LED light ) one can systimatically test each part
> of the system. Some processors that have a lot of registers,
> like the Z80 can run without RAM, making RAM test without
> any system RAM used by the program.
> I use this method on old computers as well as on pinball
> machines ( an other hobby ). It helps to have schematics
> but if you understand the basic layout of the machine and
> have data books for some of the LSI I/O chips, it doesn't
> take long to write useful test code.
> Dwight
I have one even better, I picked up a hardware diagnostic/emulator for the
Z80! The guy originally wanted $20 for it and I was willing to pay it.
When I told him what I was going to do with it he gave it to me for $5,
gave me a Moto 68K eval board (circa 81) and offered me a 8086 diag/emu
too (I had to turn him down on the 8086, too much to carry. He knew it was
going to a good home. Boy have I made use of it, it has 64K RAM, a serial
port for Intel Hex dump/load and does a great job of debugging assembly
code (hex level). One day I'll d/l the ROMs from the device (for backup of
course). Everything is TTl inside so it should be easy to keep working
(or rig to repair).
--
Linux Home Automation Neil Cherry ncherry_at_home.net
http://members.home.net/ncherry (Text only)
http://meltingpot.fortunecity.com/lightsey/52 (Graphics)
http://linuxha.sourceforge.net/ (SourceForge)
Received on Tue Jul 18 2000 - 20:42:01 BST