28 Feb
2008
28 Feb
'08
11:02 p.m.
Date: Thu, 28 Feb 2008 19:51:10 +0000 (GMT)
From: ard at p850ug1.demon.co.uk (Tony Duell)
Subject: Integral RAM upgrade
To: cctalk at classiccmp.org
Message-ID: <m1JUomf-000J3kC at p850ug1>
Content-Type: text/plain
I recently bought another HP Integral on E-bay, and after the normal
cleanup on the floppy drive it works fine. The expansion slots both
cotnained boards, one was a 512K RAM board, the other an RS232 oard
(which is the main reason I watned this machine!).
Anyway, the RAM board was clearly identical to the 1M board,
just with
only have the RAM chips fitted and the links set differently.
Having got
a lot of 41256 chips on old PC memory boards, I spent the afternoon
upgrading it to 1M.
[snip]
In my machine, wioth no RAM boards fitted. there's 264K free.
With the
512K board, it reports 764K free. And with the 1M board, 1264K free.
My question is what's happening to the other 12K of each half-meg? Or
deos 'status' have an odd definition of a kilobyte?
-tony
Don't know where the 12K is going to - maybe address space reserved for
I/O - but I have to say I was extremely impressed by the upgrade -
almost exciting reading!