Post Reply 
Found these inside a non-working 71B
03-09-2018, 08:02 PM (This post was last modified: 03-10-2018 10:40 PM by MikeSD.)
Post: #1
Found these inside a non-working 71B
I was working on a couple of prospect HP-71B that might turn out ok, if I could repair them. One has very nice LCD and bezel and keyboard. But it is one of those that has the cable and they fracture easily.

When I opened it up, I found two modules already wired inside. And the bypassed cable was already bypassed but a few wires were disconnected.

At first I thought cool, RAM. But two chips didn't make sense, unless they were high density. Who would wire a couple of 4K RAMS? I thought 32K and/or 64K?

When I tried to identify them, I couldn't make a match. One part number vaguly looks like HP 5061 7234. The only thing that comes up for that is FORTH Assembler. Could that be a FORTH module? The last digit is hard to make out. Could be '0' or '9' but the loop looks too small for a '0'.

The other one looks different from a 4K.

Any idea what these might be?


These are the only 2 internally wired devices.

[Image: comp2.jpg]

[Image: comp1.jpg]
Find all posts by this user
Quote this message in a reply
Post Reply 

Messages In This Thread
Found these inside a non-working 71B - MikeSD - 03-09-2018 08:02 PM
What's U10? - Dave Frederickson - 03-15-2018, 03:43 PM

User(s) browsing this thread: 1 Guest(s)