🚀 go-pugleaf

In article <5422@media-lab.MEDIA.MIT.EDU> henry@garp.mit.edu (Henry Mensch) writes:

   dhoelzer@csserv2.ic.sunysb.edu (David S Hoelzer) writes:
|> I'm looking for someone with information about the original 6 MHz AT
|> Memory.  Now on the XT's, there was a way to upgrade the board to 640..  I'm
|> looking for someone with info on the same thing for the 512k AT motherboard.
|> This is the full-sized baby...

  me too!  i need a 128k memory expansion for a PC/AT, and these seem to be
  (rightfully) a scarce item these days ... while my original AT has 1Mb in it,
  only 512k is visible to DOS (the other 512k is extended <??> memory, used as
  a ram diskette :>).  

  any clues would be welcome.


BocaRAM sells a card called the TophAT, which is a drop-in 128K memory
expansion for 512K AT's.  I don't remember the price exactly, but it
wasn't too bad..  

If memory serves me right, the original AT used some 128 kilobit
piggy-backed memorychips that might be hard to come by today. (I think
it was something like two 64 kilobit chips soldered together.  Anybody
out there have some sure knowledge on this ??)

On the other hand, an EMS 4.0 card can usually be set up to backfill
memory up tp 640K, giving you the effect you want and EMS memory
as a bonus. These cards run about USD 100-120 unpopulated.  Beware,
though if you intend to keep these cards when upgrading to a 386, that
some of them fail at higher processor- or bus-speeds.  Two cards known
to flunk this test are the BocaRAM AT (not the Plus), and an AST
Premium Advantage. Also, some of the older boards do not do EMS 4.0
in hardware, but only emulate it with software.  These boards cannot
be used for multitasking under DesqView/Windows-286. (The BocaRAM AT
fails this test, too.)

    -Terje









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thoger@solan.unit.no       |                 Institute of Physical Chemistry
THOGER AT NORUNIT.BITNET   | Div. of Computer Assisted Instrumental Analysis
                           |               Norwegian Institute of Technology