knudsen (02/22/83)
Can someone help me answer these: 1) How ffast must the RAM be in the CoCo? I put in some 400-ns cycle(?)-time chips and it mostly works. But i've seen ads for 250-ns access(?)-time chips. Are mine too slow? 2) Why does my "E"-board CoCo sometimes get the idea on power-up that I have 4K instead of 32K, when the RAMSIZE jumper is in either 32K or 16K slot? 3) Why does BASIC *not* have problem (2) above when when a cartridge (with interrupt lead cut) is inserted? Does this load the bus just right? Note--the Radio Shack Diagnostic rompack now consistently reports my RAM is OK, tho it can only check the lower 16K (it's an old pack). PS--I found that 64K rams can be very intolerant of +5 voltage variations. Mine work best on exactly 5.0 V. The Shack had set my CoCo for 4.8V, and the chips were very flaky. Also, you have to set the one jumper to HIGH, not LOW, so that the 'ls02 buffers MA7; the SAM can't drive that line well enuf by itself. thanks, mike k
wagner (03/01/83)
Radio Shack is now selling 64k upgrades (advertised as 64, not 32), said to be trivial for the E revision board, difficult but doable on the D revision board (which I, sigh, have). Does anyone know how well this allworks, whether basic can get at it all, and whether it is compatable with Frank Hogg Flex? Thanks. Michael