A2Pro wrote:
OK, I found one of them. But it has only 3 MB of RAM chips in it
plus a note on it that says it passes the AE memory test OK with the 3
MB but if additional banks of RAM chips are added then 1 of the 24
chips comprising the first 3 MB, that previously tested OK, shows up
as bad. VERY odd...
Not so odd. Each chip adds loads to the address lines, and one of the chips in the first 3MB has marginal speed. "Good" and "bad" are not as binary as they sound--they just describe whether a particular chip works in a particular configuration. A chip that is marginal may work fine until you "push the envelope." Replace the "bad" chip and you will probably be able to load it up with DRAM (unless there are other marginal chips). BTW, this points out the value of being able to do full margin testing on DRAMs, both for voltage and timing variations--not easy on stock systems. -michael NadaPong: Network game demo for Apple II computers! Home page: http://members.aol.com/MJMahon/ "The wastebasket is our most important design tool--and it's seriously underused."