Hazeltine 1500 Technical Info.

From: ajp166 <ajp166_at_bellatlantic.net>
Date: Mon Aug 13 17:53:41 2001

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_at_itt.com>
To: classiccmp_at_classiccmp.org <classiccmp_at_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
Received on Mon Aug 13 2001 - 17:53:41 BST