Are these what i think they are?

Ok i just found a couple of chips that might be useful.

They are: UCN5812AF - BiMOS II 20-BIT SERIAL-INPUT, LATCHED SOURCE DRIVERS WITH ACTIVE-DMOS PULL-DOWNS

Data Sheet:

I kind of understand the 20 bit shift register part of it but don't understand what else it can do. The data sheet is a bit Greek to me. The chips are coming out of an old security monitoring system that has an array of LEDs on the from which are tied to these chips. So is this something i can use like a regular shift register? Is there more i can do with it? How to i interface this with the arduino?

The unit also has this CDP6805E2E - Microprocessor Unit.

Data Sheet: CDP6805E2E pdf, CDP6805E2E Description, CDP6805E2E Datasheet, CDP6805E2E view ::: ALLDATASHEET :::

So this might be interesting to figure out and play with as well. Good news is if there is something to all of this i may be able to get my hands on a few more. At the very least i'm getting 10 green LEDs, 10 orange LEDs, and 11 red/green LEDs.

Thanks everyone.

I think the 5812 was originally designed as a driver for vacuum fluorescent displays: hence the 60V maximum VBB.

They're useful for driving LEDs, too. You can also use them for driving non-logic power FETs, because they can give you a nice high gate voltage.

The 6805 series are cute little micros. There are free cross-assemblers (and maybe compilers. But i don't think there's anything as sophisticated as the gcc used for Arduinos) for them. The one you have needs an external EPROM/flash chip to store the code. There were also versions with on-chip EPROM (that was back in the days before flash was invented), that freed up the address and data bus pins for use as I/Os.

Ran

Cool, thanks for the info.

Yea the board has a pair of EPROM chips on it with the alarm system code on it. As denoted by the stickers attached to the chips. There is also an uknown chip soldered to the under side of one of the EPROMs. We'll see what that is after some desoldering. The 5812s pretty much have all the LEDs running strait to them.



Fortunatly these chips are all in sockets. There is also a 74VHC942 300 Baud Modem chip in a socket.