13 Aug
2001
13 Aug
'01
5:53 p.m.
Hi used to know that beast like the back of my hand.
Try this, pull the keyboard encoder (ay3-3500, 25 year memory test!)
and see of the problem goes away. Those encoders somtimes get
static blasted. I may even have an encoder (still!) for that one.
Also try removing and banging the board to shake out loose junk on it.
Allison
-----Original Message-----
From: Messick, Gary <Gary.Messick(a)itt.com>
To: classiccmp(a)classiccmp.org <classiccmp(a)classiccmp.org>
Date: Monday, August 13, 2001 2:40 PM
Subject: Hazeltine 1500 Technical Info.
Does anyone have any technical documentation for a
Hazeltine 1500? I
just
plugged mine in, and it seems that I have some
problems. I'm getting
cap.
O's in the top half of the display, and overtyping
does not always
produce
the proper character. Everything's fine on the
bottom half of the
screen.
I'm thinking I have a bad RAM chip. Looking at the
board, it's an 8080
with
IIRC 21L02's for RAM. I don't own a logic
analyzer, and haven't
correlated
the ASCII codes to see what bit's are stuck.
Any help would be appreciated.
Gary