[vcf-midatlantic] Anyone know of a bulk way to test MK4027 dram chips
mike at willegal.net
Wed Aug 15 13:48:22 EDT 2018
Depends upon if you are interested in testing for speed, as well as for simple good/bad bits and good/bad addressing.
Here are some stray thoughts, if you are just interested in good/bad bits.
1) I think you might be able to take an Apple II language card and possibly run 4027s in them, perhaps without mods. Change out the sockets to ZIF sockets and modify the 6502 memory tester to test 8 chips at a time in the language card. The Apple version of the language card has space for a ROM, so you could possibly burn the test program into an PROM and have it run automatically. Probably turn out to be an involved project.
2) Might be easier to just replace one bank of DRAM sockets on an early II plus motherboard (one with the memory jumper blocks) with ZIF sockets and use the aforementioned memory test.
3) Another idea would be to enhance the SCELBI based 1101/2102 tester, to support refresh and CAS/RAS addressing. Probably turn out to be an involved project.
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