Mystery Chip on an Old Alarm System - Page 1
Forum section: electronics / general

author: amccarter1990
author_rank: Newbie
timestamp: November 21, 2016, 04:13:04 am
content: Hello all, I am new to the eevblog forum and am very excited to be a part of the community! Anyways, the reason I am on here is because I am looking for info on a chip I found on the motherboard for an old home security system. I will attempt to upload a pic from my phone, but I know it's an intel chip I just can't find any info on it using google.The chip markings say this:MHS(C)PITTWAY '96N9636(C) INTEL 80,829609 .Z04383AIt is a 40 pin DIP. Please help! I am interested because this could be a neat chip to harvest if I could learn how to use it.

author: ale500
author_rank: Frequent Contributor
timestamp: November 21, 2016, 09:05:25 am
content: Maybe the pinout can say something, like it is a mask-rom version of a 80c31 or 80c51...Why do you want to harvest it ? You can get good alternatives with documentation and tools for few cents (plus shipping)...

author: amyk
author_rank: Super Contributor
timestamp: November 21, 2016, 10:40:33 am
content: Mask ROM 8051. You may be able to use it as an 8031 by disabling internal ROM, but you will need to supply your own.

author: Kjelt
author_rank: Super Contributor
timestamp: November 21, 2016, 10:57:30 am
content: Yes indeed the "(C) INTEL 80" would suggest a 8051 family member, not very worth salvaging if you ask me, you are better of using a modern 8 bit ICP microcontroller that has 10x the RAM and ROM and performance and uses 10x less power

author: XFDDesign
author_rank: Frequent Contributor
timestamp: November 21, 2016, 02:38:32 pm
content: Quote from: Kjelt on November 21, 2016, 10:57:30 amGiven that (C) INTEL 80 is proceeded with ,82, that would tell me Manufacturing years 1980-1982, not that it's an 80x51.

author: Kjelt
author_rank: Super Contributor
timestamp: November 21, 2016, 04:37:16 pm
content: To me they are the copyright years just as that the 8048 has 78 i believe on them. The production year and week are the other numbers 9609 week 9 in 1996.

author: amccarter1990
author_rank: Newbie
timestamp: November 22, 2016, 12:00:50 am
content: Quote from: ale500 on November 21, 2016, 09:05:25 amI appreciate what you are saying, and agree, however I am just interested in seeing if I could interface with it; I mean I already have it! I've always been interested in older tech and just thought it would be cool to re-purpose it.

author: amccarter1990
author_rank: Newbie
timestamp: November 22, 2016, 12:02:20 am
content: Quote from: Kjelt on November 21, 2016, 10:57:30 amThanks! Like I said in the above reply, it's more or less just a thing I'm interested in doing specifically because I already have it and thought it would be neat.

author: amccarter1990
author_rank: Newbie
timestamp: November 22, 2016, 12:08:09 am
content: Here is the pic I promised!

author: BradC
author_rank: Super Contributor
timestamp: November 22, 2016, 03:18:09 am
content: Is that an old Ademco system?

author: amccarter1990
author_rank: Newbie
timestamp: December 08, 2016, 10:32:30 pm
content: It's from an ADT system. I'm guessing they're a USA company and don't have products outside that market but I could be wrong!

author: stj
author_rank: Super Contributor
timestamp: December 09, 2016, 09:25:58 am
content: MHS had / has a license to produce 8051/8052 core cpu's,they may be flash based - i had some free samples in my spares box a while back.

author: wraper
author_rank: Unknown
timestamp: December 09, 2016, 09:39:07 am
content: Quote from: XFDDesign on November 21, 2016, 02:38:32 pmThey are copyright dates. "(C)PITTWAY '96" suggests it cannot be older than 1996. Then 9609 should be a date code, year 96, week 9.

author: BradC
author_rank: Super Contributor
timestamp: December 09, 2016, 11:29:23 am
content: Quote from: wraper on December 09, 2016, 09:39:07 amYeah, it'll be an 8051 derivative. Pittway made a whole heap of security gear and the reason I asked about Ademco as they'd owned them (as in Pittway bought Ademco) for many years prior to 96. I still wake up screaming in terror after a lightning storm at the thought of getting into work to a shoulder high pile of Ademco panels & diallers after any sniff of lightning back 93-97. We'd get 10 faulty American made panels to 1 locally produced. They were either lightning magnets or just made of cheese. Awful stuff.That 40 pin dip with the Pittway copyright is burned into my memory to incite terror on sight.

author: technix
author_rank: Super Contributor
timestamp: December 09, 2016, 03:26:12 pm
content: The location of the resonator and the array of the resistors around pin 40 tells me it is likely a traditional 8051 microcontroller. If you want to suck it out of the board and reuse it, you can reuse it with its internal ROM disabled and supply your own program code in external code (and data) memory, at the cost of losing half of the I/O lines.