atn@cory.Berkeley.EDU (Alan Nishioka) (05/20/91)
I need help identifying some Motorola chips. They all have the Motorola M insignia, but I can't find them in the usual places. I have looked in IC Master, the Motorola Master Selection Guide, various Motorola Databooks, and Motorola Specs in Secs (data on disk). Are they special chips made just for spcific companies? Are they regular chips with special part numbers (like HP chips)? Found in a Radio Shack Color Computer 2: SC77527P 16 pin 8423 date code seems to be a voltage regulator SC77526P 20 pin 8329 date code SJ5812 3 pin 8326 date code seems to be a transistor Found in a General Telecomputer Telephone Extension device: SC94023P 28 pin 8531 date code PCS9002 (other lines found on same chip) A61A8531 ----------------------------------------------------------------------------- Alan Nishioka KC6KHV atn@cory.berkeley.edu ...!ucbvax!cory!atn 974 Tulare Avenue, Albany CA 94707-2540 37'52N/122'15W +1 415 526 1818
whit@milton.u.washington.edu (John Whitmore) (05/25/91)
In article <13711@pasteur.Berkeley.EDU> atn@cory.Berkeley.EDU (Alan Nishioka) writes: >I need help identifying some Motorola chips. >Found in a Radio Shack Color Computer 2: > >SC77527P 16 pin 8423 date code seems to be a voltage regulator >SC77526P 20 pin 8329 date code These are special-purpose ICs, which only Radio Shack can help you with. Fortunately, they are field-replaceable units (socketed), and Radio Shack offers service (i.e. you can buy spares). One is "U3", and is a DAC of sorts. Inputs are pins 13-16, connected to the joystick connector, and addressed by the PIA chip via two analog select lines, pins 11 and 12. The cassette output and sound drivers are also on this chip. It includes a comparator, so that the DAC output can be compared with an input (so you can measure input voltages this way). This is a 20-pin chip. The other, "U1" is called the SALT chip (supply and level translator) and includes voltage regulation and the cassette READ circuitry. This is a 16-pin chip. If you want full information, contact Radio Shack and ask about the Color Computer II Service Manual. John Whitmore