So on bootup, I now have the hardware do a memory check. I basically take and write out a bunch of values to the memory, and then read them back and make sure they read back properly. The values written are based on the 16-bit memory address…….If it succeeds it writes, “MEM-OK” to the serial port, a “MEM-FAIL” is a pretty bad error and the program refuses to run. No sense in continuing on if the memory is bad.
Quick dirty code, but it does the trick. I can’t really cause a failure without screwing w/ the hardware…. I guess I could momentarily touch the data pin to ground or something that should cause it to read/write a misplaced 0…..
The more I test hardware for a living, the more test cases I can come up with to put this thing through its paces.
Last night, until 2:30am, I had my Amiga 500 hooked up to my logic analyzer. Can’t figure out when Paula is dma’ing the 16-bit words to memory, I’ve got to look at clocks etc. I think the DMAL pin should be pulsing at some point. When I get more time to work on it, I’m going to take a look. I’ve got to order more of those xgrabbers or whatever the heck they are called. Mini probes basically….
More later………..
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Thanks for sharing this grat article with us!
the amiga 500 make me louco!