[comp.sys.ibm.pc] Leading Edge Memory Expansion

thollowe@oucsace.cs.OHIOU.EDU (Tom Hollowell) (02/14/89)

I have a Leading Edge computer and it now has 512K.  What I need to know is
what type of chips do I need to upgrade it to 640 K.  What ns speed can I
use?  The manual doesn't tell, and I cannot get a hold of LE for an answer.

Any help would be appreciated.  Thanks.

silver@eniac.seas.upenn.edu (Andy Silverman) (02/15/89)

In article <450@oucsace.cs.OHIOU.EDU> thollowe@oucsace.cs.OHIOU.EDU (Tom Hollowell) writes:
>I have a Leading Edge computer and it now has 512K.  What I need to know is
>what type of chips do I need to upgrade it to 640 K.  What ns speed can I
>use?  The manual doesn't tell, and I cannot get a hold of LE for an answer.
Leading Edge's Tech support has never been particularly wonderful.  What you
need (assuming you have their Model D XT clone), is 9 41256-type chips rated
at an access time of 150 ns.  Lower ns numbers will also work but they are
more expensive than what you need.  Note that this gives you a total of
758K of memory, but Leading Edge computers give you no way at all to access
the extra 128K.  Their board should have been designed to take 128K or 64K 
chips, as the 256K chips are more expensive yet less useful on that
particular motherboard...



Andy Silverman
Internet: silver@eniac.seas.upenn.edu
CompuServe: 72261,531

cal@data.UUCP (Cal Rasmussen) (02/21/89)

You need 256k 150ns chips (9 of them).  A jumper plug on the mother board
must be changed.  Your user manual shows the location.

The extra 128k of ram can be used for a RamDisk.

silver@eniac.seas.upenn.edu (Andy Silverman) (02/21/89)

In article <376@data.UUCP> cal@data.UUCP (Cal Rasmussen) writes:
>You need 256k 150ns chips (9 of them).  A jumper plug on the mother board
>must be changed.  Your user manual shows the location.
>
>The extra 128k of ram can be used for a RamDisk.
Do you mean the extra 128K that you get from adding the chips (513-640K) or
are you talking about the 128K that is wasted by having to use 256K chips to
fill a 128K address space?  As far I can tell there is no way to access the 
128K above the 640K address space.


Andy Silverman
Internet: silver@eniac.seas.upenn.edu
CompuServe: 72261,531