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Need help identifying VERY OLD Intel chips

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Breadfan

Inactive Moderator
Joined
Jan 4, 2001
Location
Northern VA
Ok, well, I have this jar 'o chips as I call it, which has been filled with various chips pulled off of circuit boards. A few of the chips were cool, becuase they had the glass windows in the middle. Well, I was using my jar 'o chips in a webgraphic, and started looking through the various chips.

I found the ones iwth the windows, 2 of them atleast, and they are intel chips. (the big "i" gave it away).

I can't quite remember where these came from, so I have no idea what type of chips they are. It would be VERY cool to find some info about them. I'm not sure if maybe there is a way to cross reference numbers on Intel's site...

Anyway, here is the info off the chips and a picture of their info for reference. They are long DIP (dual inline package) chips, that remind me alot of how the original 4044's looked (though I doubt these are 4044's). The copyright dates are '82 and '84.

Here's the info:

LEFT CHIP
D27256-2
U72188MZS
PGM @ 12.5v ( :eek: ...12.5 volts!)
(c) '82, '84

RIGHT CHIP
D27256-2
U72076MZS
PGM @ 12.5v
(c) '82, '84

And here's a pic (note the cool windows! heheh, I'm gonna mod my northbridge w/ a window like this. J/K!!, :) )

chipss.jpg


So, any info you might have is definitely welcome!

Mike
 

eh?

Member
Joined
Sep 2, 2001
Location
Elkhart, Indiana
I think its a memory chip. An EPROM (Erasable Programmable Read-Only Memory) Its a re-usable memory chip that can be programmed electrically and erased by exposure to ultraviolet light. Once it is programmed , it acts just like a ROM (Read only Memory), but once ultraviolet is shined through the crystal window it will erase the chip and then you can add another program to is. BTW when the chip is running that little window is covered to prevent you from accidently erasing it:D
 
Last edited:

zoopa_man

Member
Joined
May 24, 2001
Location
NY where the cows out number the people
Look like EPROM eraseable programable read only memory Use to use a infared light to erase the chip and then reprogram it with a new bios or what ever went on the chip......They usualy have a sticker over the flash hole though....so don't hold me to this either...but that's what my guess would be.
 

eh?

Member
Joined
Sep 2, 2001
Location
Elkhart, Indiana
looktall said:
yep.
it's a UVEPROM. (as opposed to an EEPROM.)

it uses UV light instead of electricity.
you guys both posted before i edited mine. Its a EPROM its a given that UV is used...

BTW once the chip is powered on it will cover the windo automaticly
 
OP
Breadfan

Breadfan

Inactive Moderator
Joined
Jan 4, 2001
Location
Northern VA
Cool, you jogged my memory there...I had totally forgotten the purpose of the window, but remmeber as a kid hearing something about that...

Anyway, thanks for help...I googled the number, and found a few for sale at EPROM sites (one for HAM radio).

So here's what they're selling and the link:

" 1 Intel D27256-2 32K 200ns."

http://hamradio.cmcorp.com/inventory/LOGIC/EPROM.html

So each is a 32k chip. Hmmm, these are for sale at places, wonder how much :) Would be funny if they are hard to find so replacement chips sell for 10 or 20 bucks, lol.

Thanks for the help, I get a kick outta finding out about some of the older stuff lying around...

Mike
 
OP
Breadfan

Breadfan

Inactive Moderator
Joined
Jan 4, 2001
Location
Northern VA
OMG!

WOAH! Go Here: http://www.mistersprockets.com/ics.html

And scroll down looking for Part Number = D27256-2

They are my chips, and they seem to be selling them for $50 a piece!!!! Man I should see if these guys want two more at $25 a piece and buy an XP1600 or something, LOL

Thats CRAZY!
Mike