maddox@ernie.Berkeley.EDU (Carl Greenberg (guest)) (07/11/87)
I have a UNIQ 286B IBM AT clone. It's nice: SI 11.5, 40MB, a megabyte of RAM. However, I have a problem with that last item. The scanty information in the manual informs me that I can tell the system it has 512K, 640K, or 1024K of RAM on the main board (I don't have any expanded or extended memory boards). When I tell it it has 640K of RAM, the thing countsand then acts like it has 640K of RAM. When I tell it it has 1024K of RAM, it only works with 512K regular/512K extended. This allows a 512K RAMdisk, but I like having 640 for TSR stuff and Ventura Publisher. Setup has no qualms about telling it 640K/384K, but then when I boot it up the thing gritches about a memory size error. Do I get a better setup program than IBM AT Advanced Diagnostics V 1.04, do I find a different set of BIOS ROMs than the Award BIOS that came with the thing, or do I ignore the upper 384K of memory? TNX in advance Carl /----------------------------------v------------------------------------------\ | Carl Greenberg, guest here | "I have a very firm grasp on reality! I | | ARPA: maddox@ernie.berkeley.edu | can reach out and strangle it any time I | | UUCP: ...ucbvax!ucbernie!maddox | want!" - Me |
philip@amdcad.AMD.COM (Philip Freidin) (07/14/87)
< owner of UNIQ 286B reprots problems with splitting 1 meg of ram >
Because of the way memory decode is done, AT-clone motherboards differ in the
way they handle more than 640k on the mother board.
Some allow for the 1 meg to be split at the 640k boundary, and the remaining
384 k is remapped to the 1 meg boundary. The logic for this requires a few
chips, and the better motherboards do this.
Others, allow for 1 meg of ram, and either give you 640k and ignore the rest,
or split at the 512 k boundary, and remap the second 512 to the 1 meg boundary
The logic for this is much simpler, and is therefore much more common in the
at-clone cards.
If your card is the second category (and your description indicates that it
certainly is), there is nothing you can do with bios proms or setup sw
that will fix the problems.
I recomend you run 640k of main memory, ignore the missing 384k, and
buy some 2 or 4 meg ram cards for the ram disk
Hope this is of some marginal help
Philip Freidin @ AMD SUNYVALE on {favorite path!amdcad!philip)
Section Manager of Product Planning for Microprogrammable Processors
(you know.... all that 2900 stuff...)
"We Plan Products; not lunches" (a quote from a group that has been standing
around for an hour trying to decide where
to go for lunch)