[comp.sys.zenith] SupersPort 286 memory.

danielce@uluru5.ecr.mu.oz (Daniel Ake CAROSONE) (05/04/90)

I am puzzled about the memory configuration in the SupersPort 286.
Looking at the chipset on the motherboard, I can clearly see 1Mb
of memory chips, all connected.

In the SETUP facility of the MFM-200 monitor, the item referrring to 
addidtional memory says "the amount of memory above 1Mb"

However, when the MFM-200 boots, it says "Total Memory: 640Kb"

All attempts to find this memory by all sorts of means has failed, I
cannot get anything to use it, either as expanded or extended. The single
exception is using PC-Tools Deluxe Rev 4.24, which reports that I have
an EGA card with 256K of memory - blatantly untrue, but at least it found
*something*. Attempts to directly read locations in that memory space yield
mixed (usually bad) results.

I called Honeywell-Bull, who repair the machines here, and the tech was very
helpful, saying that, as he understood it, the extra memory was being used
to map video memory, but this could be configured out. How?

I currently run DOS 3.21, from Zenith. BIOS 3.37.

I am considering changing to run Xenix, mainly for novelty value. Has 
anybody else tried this? I do know that the laptop won't run Microsoft
MS-DOS, from experience it just won't boot it. It needs a modified DOS
from Zenith. Will it run Xenix, or do I have to use my desktop instead?

Does anyone, particularly at Zenith, have any info, the more technical the 
better? Another poster mentioned success at getting EMM to use that memory.

Thanks in advance
danielce@ecr.mu.OZ.AU

huntley@silver.ucs.indiana.edu (Haydn Huntley) (05/05/90)

In article <3909@munnari.oz.au> danielce@uluru5.ecr.mu.oz (Daniel Ake CAROSONE) writes:
| I am puzzled about the memory configuration in the SupersPort 286.
| Looking at the chipset on the motherboard, I can clearly see 1Mb
| of memory chips, all connected.
| 
| In the SETUP facility of the MFM-200 monitor, the item referrring to 
| addidtional memory says "the amount of memory above 1Mb"
| 
| However, when the MFM-200 boots, it says "Total Memory: 640Kb"
| 
| All attempts to find this memory by all sorts of means has failed, I
| cannot get anything to use it, either as expanded or extended. The single
| exception is using PC-Tools Deluxe Rev 4.24, which reports that I have
| an EGA card with 256K of memory - blatantly untrue, but at least it found
| *something*. Attempts to directly read locations in that memory space yield
| mixed (usually bad) results.
| 
| I called Honeywell-Bull, who repair the machines here, and the tech was very
| helpful, saying that, as he understood it, the extra memory was being used
| to map video memory, but this could be configured out. How?
| 
| I currently run DOS 3.21, from Zenith. BIOS 3.37.
| 
| I am considering changing to run Xenix, mainly for novelty value. Has 
| anybody else tried this? I do know that the laptop won't run Microsoft
| MS-DOS, from experience it just won't boot it. It needs a modified DOS
| from Zenith. Will it run Xenix, or do I have to use my desktop instead?
| 
| Does anyone, particularly at Zenith, have any info, the more technical the 
| better? Another poster mentioned success at getting EMM to use that memory.
| 
| Thanks in advance
| danielce@ecr.mu.OZ.AU

Your Zenith may use a little bit of that extra 384K for video, but not
most of it.  If one puts a line containing "DEVICE=C:\DOS\EMM.SYS" in
CONFIG.SYS, then one can use 256K of that otherwise unused memory as
EMS memory.  You may need to ask a friend or dealer to give you the
latest version of Zenith's MS-DOS to get this to work.  I'm using the
EMS 4.0 Driver, Version 3.30.14 and MS-DOS Version 3.30.

I am still hoping someone will post the correct command for getting
ZCACHE.SYS to use that 256K of EMS memory as a hard disk cache.

--Haydn
*****************************************************
*  Haydn Huntley    huntley@silver.ucs.indiana.edu  *
*****************************************************

querubin@uhccux.uhcc.hawaii.edu (Antonio Querubin) (05/05/90)

The extra 384K of memory in a Supersport 286 is useable only as expanded
memory.  Press Ctrl-Alt-Ins and enter 'setup'.  Then seleect the memory 
configuration as expanded memory even though you don't have memory beyond the
1 Mbyte limit.  This will let emm.sys see 256k of this extra memory as
expanded memory and all your software that knows how to use expanded memory
can now access it.  128K of memory is used to hold a copy of the BIOS as 
'shadow RAM'.  The BIOS code runs faster when executed from RAM than from ROM.

I complained to Zenith about this 'deceptive advertising'.  If they were gonna
steal 128K for 'shadow RAM' then they should have said the Supersport 286 comes
with only 916K of useable RAM.  Or provided 1132K of RAN in the first place.

bjstaff@zds-ux.UUCP (Brad Staff) (05/07/90)

Daniel:

One of the software engineers here has been using a SupersPort 286 to run
Xenix 286, so it is known to work on that machine.  Regarding the inability
of your machine to run vanilla MS-DOS:  I checked with our TRC (Technical
Response Center), and there are no reported problems of that sort.  We could
think of no reasons why it shouldn't work, but I asked them to check it out
anyway.  I think your other questions have been answered accurately by others,
so I won't repeat that information here.

Happy computing,

-- 
Brad Staff
Zenith Data Systems
616-982-5791
bjstaff@zds-ux.zds.com