Hi Gary, I use the Version 03 16MB SRAM board with 2 x AS6C3216 for 8MB of RAM. It has been built 'Stock' without modification and I've never had an issue even with the 80386 (although I confess that board is hardly in my system)
Just a thought have you double checked the address decoding jumpers ? K3 should be position 1-2 for the AS6C3216 chips Jumper P2 should be 1-2, and P3 should be 5-6 If these are wrong you will get address decoding issues Regards David On Tuesday, July 21, 2015 at 2:35:40 PM UTC+1, Gary Kaufman wrote: > One board that's been frustrating me for a long time has been the Version > 03 16mb SRAM board with the 80386 processor board > > I built one of the earlier mezzanine based boards which worked well with > 2mbx8 SRAM (Cypress CY62167ELL-45ZXI 45ns 5v), but was never able to get > the V3 board to work properly with 4mbx8 SRAM (Alliance AS6C3216 55ns > 3.3v). The errors were unpredictable, but most commonly resulted in 55H > fill errors in the A00000-BFFFFF and E00000-FFFFFF range and almost random > 1234H fill errors anywhere in memory. The errors weren't isolated to a > single bank or SRAM and wait states / clock speed didn't seem to change > much, although it was more stable at very low clock speeds. > > After several months of intermittently trying things, I substituted 74F240 > for U9 and 74F139 for U4. The board has run two full passes of the > protected mode "J4" test without a single error. > > Hopefully this might save someone else a bit of time. > > - Gary > -- You received this message because you are subscribed to the Google Groups "N8VEM-S100" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
