New here and some chips I have had from the 80's

[grimm]

Hi and hello,

I'm new here and wanted to share some chips I have kept around since the 80's. I was in collage at the time doing my electronics degree. Many companies in the area would donate their old computer equipment for us to play with. One company gave us a huge cardboard box completely filled with ic chips. The professors just said that we could take what we wanted so I pulled out a bunch of the white ceramic and gold ones because I thought they looked cool. I would love to find out what they were used for. I think that they were used in calculators but I'm not sure. They appear to all date from the 70's and were made by NCR. The ceramic is very thin maybe only 1/8 inch thick.

The collection is comprised of these chips:

nine 6-51056
185
7304A
24 - pin

seven 6-51057
185
7315A
24 - pin

three 6-51055
5310
16 73 M
24 - pin

one NCR 8241
6-55722
M454081M
USA
24 - pin

one NCR 6-51195
C 7565 10-76-H
24 - pin

one NCR 6 51375
322996 7801
40 - pin

They all have a red mark on them (except the last three), maybe they were bad? Any information would be great, google didn't help any. Thanks,

[jrmunro]

Welcome to the forum.

Pictures would be better if you can supply them.

[grimm]

Sorry about that, I should have known. Here are some really bad ones I just took, I hope they are good enough. I flipped some over so you could see how they look on the bottom. The only one with anything printed on it is the big 40-pin one, looks like it was made in Mexico.











Thanks again,

[grimm]

No ideas? I did find this page that has pictures of a NCR display board that has some of the chips in it, but no additional information.

http://ferretronix.com/stuff/vfd.html

Maybe they are driver logic for the display?

[johnorun]

[JAC]

I always thought nice mounting holes.

lol

[doccybrown]

lol holes for mounting, of course they are made
to save weight, improve heat dissipation and just cooler look

These chips are really nice but the NCR-terrain is
completely unexplored...
When I see the ROM or RAM-alike chips (probably they are)
it is certainly true some of the big NCR-chips that
appear from time to time are processors or at least
many of them work like a CPU.
Those chips can be found in very old cash registers, terminals and
computers made by NCR, looks like later systems
had mainstream chips/processors inside...
We need more detailed informations which are not available!

[grimm]

[grimm]

[gshv]

Well, "6-5xxxx" could be custom numbers, in which case it'll be almost impossible to identify them. "6-" could also be a prefix, and 5xxxx could be an NCR part number. My earliest NCR databook from 1985 shows 52xxx and 59xxx part numbers. Those are different type of memories, like NVRAM or EEPROM. The 51xxx and 55xxx could be some type of memory too.

Gennadiy

[donutty]

Looks like some of them you have multiple of. Maybe the easiest way to identify is pop the lid off and then you can tell from the structure / layout if it is a processor, RAM, ROM or other.

[grimm]

Thanks guys,

I hope it will not come to opening some of them up, I would rather not. I did run across an interesting reference book. I just bought it and I hope it has these chips in it. The photos of some of the pages from the book do mention desktop calculators, so there might be some hope. Here is the ebay page on it:

IC FUNCTION LOCATOR 1978 222 pgs
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rt=nc&nma=true&item=180574978173&si=K2l2riVdGZvMpJEZV71eMsQngsY%253D&viewitem=&sspagename=STRK%3AMEWNX%3AIT

When I get the book in a week or so I will let everyone know what's in it.

[Guest]

Well I finally got the book today and there were 0 (zero) NCR entries in it. It has a whole bunch of other chips listed though (over 40 manufacturers) so it might be a good source for chips pre 1978.

[grimm]

Oops, that last message was from me, just forgot to log in.