Does anybody know of a spec sheet for a NEC D553C and a NEC NEC D1771C 011

[Blanka]

Just was trying to get the working of a game PCB, and it has 2 chips.
One is a NEC D553C, a 42 pin DIP chip, probably a microcontroller,
The other is a NEC D1771 C011, a 28 pin DIP. Maybe it is a microcontroller too, but it seems to drive the speakers.
Anybody who has some info on these, or know a relevant family they belong too?

[ed12]

1 is a pia
is the processer a 8080 ? or such family ?

ed

[Blanka]

What is a Pia?
No 8080 family. The D553C must be a 4 bit microcontroller, with RAM, ROM and high-voltage (+/- 45V) output to drive a VFD display.

[ed12]

peripheral interface adpater

common front end for a micro
if the nec 553-xx is the olny 48 pin chip ? on that board
then it might be the micro with ram/flash

i suggest u dig deeper
a pic will tell a story here
as nec is very very quiet about what how where when why with there chip's

ed

[boardjunkie]

http://www.vstservice.com/p-1296-ic-nec-d553c.aspx

[Blanka]

Found that page too. But no specsheet there. Maybe I can mail them if they have any info.
Or I can go to the Tech University and dig up some fungus-books in a paper library

[ed12]

nope notta zip
nec dose not hand out there spec's
expect to state what it is
 u cannot yank it out of them
and the reason is easy
they lock into a :nda: with the board mfg
this is why u should :spec: the game
we will back track it for u

ed

[Blanka]

NEC is telling everything about their 2-year later model the 7528. Doubt there is no similar sheet for the 553