found an old micro computer chip.......? - Page 1
Forum section: electronics / beginners

author: saipavan
author_rank: Contributor
timestamp: July 22, 2014, 02:56:24 pm
content: I found a chip,d80c42c,on an very old motherboard.from a google search i found that it is an 8 bit micro controller.it's manufacturer is nec.can any one explain how can i use it ....

author: mariush
author_rank: Super Contributor
timestamp: July 22, 2014, 03:04:45 pm
content: If it really is a uPD80C42, you can read the datasheet and learn how to program it (if it's not factory programmed).Datasheet is here:http://www.ic-on-line.cn/view_download.php?id=1513130&file=0258\d80c42c261_175969.pdfMy opinion.. throw it away, it's pointless to waste time with it. You can now get arduino or PIC chips that are way better and easier to work with compared to those old chips.

author: oPossum
author_rank: Super Contributor
timestamp: July 22, 2014, 03:15:15 pm
content: The 8042 was used as the keyboard controller in the original IBM PCs, and also in the keyboard itself. For many years it was also used by the PC clones. It has long been replaced by integrated controllers on the motherboard and a variety of microcontrollers in the keyboard. The 8042 is an Intel design that was licensed or cloned by a few other manufacturers. Came before the more popular 8051/8052.

author: DJohn
author_rank: Regular Contributor
timestamp: July 22, 2014, 03:51:22 pm
content: The datasheet doesn't say, but it's almost certainly mask programmed. It will do the job it was programmed to do, and there is no way to change it.If you want a different program, you give it to the factory before you order the next hundred thousand chips, and they'll change the mask used in the appropriate stage of manufacture. Or rather, they won't, because I can't imagine they've made these things for decades.

author: rob77
author_rank: Super Contributor
timestamp: July 22, 2014, 04:12:30 pm
content: if you're collecting vintage micros then add it to your collection , otherwise drop iteven if it has external bus it's simply not worth of messing with it (eprom or parallel flash needed).if you're interested in the '51 micros, then i would recommend the "S" variants from Atmel AT89S51 or S52, those S variants have serial in system programming similar to AVR ( avr micros are used in arduino), internal program flash and they can execute code from external memory as well and last but not least, they're fairly cheap - below 2Eur in single piece quantities.if you're interrested in micros in general - then go ahead with AVR or PIC. arduino (avr micro) is a good starting point for young players, once the young player grows up and need more application specific micro - then microchip (manufacturer of PIC) has a really wide range of micros.

author: oPossum
author_rank: Super Contributor
timestamp: July 22, 2014, 04:37:27 pm
content: The 8042 is mask ROM - so you can't change the firmware. The 8742 was the EPROM version.Wikipedia has a summary of the MCS-48 family...http://en.wikipedia.org/wiki/Intel_MCS-48

author: free_electron
author_rank: Super Contributor
timestamp: July 22, 2014, 04:55:25 pm
content: Quote from: saipavan on July 22, 2014, 02:56:24 pmlicence the core, build waferfab , write code and have rom maks made.in short : you can't this is mask programmed.