EMS on Zenith SuperSport 286

[paul.brett]

My Zenith SuperSport comes with 1024Kb of EMS. BIOS version 3.39, DOS version 3.21. The EMS driver is loaded via config.sys with emm.sys and reports:

"The Expanded Memory Driver is Installed"

However, if I try to use smartdrv.sys (with 1024 /a options) the boot process hangs, or says "invalid command interpreter".

I have tried a 3rd party disk caching program called dcache (c) 1988 Douglas Boling. This works if I use /M128, but any higher values tend to bring up all sorts of weirdness.

Does it sound like maybe some of the memory on the EMS board is shagged? What testing programs can you recommend that will test EMS memory?

Thank-you.

 

[paul.brett]

I used Checkit PC Diagnostic Software 3.0 by Touchstone Software Corporation.

The EMS test always fails with parity after testing from block 40000h.

ERROR at Addr EMS:0040000h, Bits .......8........ Parity
ERROR at Addr EMS:0040002h, Bits .......8........ Parity
ERROR at Addr EMS:0040004h, Bits .......8........ Parity
ERROR at Addr EMS:0040005h, Bits .......8........ Parity
ERROR at Addr EMS:0040008h, Bits .......8........ Parity
ERROR at Addr EMS:004000Ah, Bits .......8........ Parity
ERROR at Addr EMS:004000Eh, Bits .......8........ Parity
...

So, it seems I have one (or more) duff chips.

Do you think re-seating them might be possible / help in any way?

Thank-you.