Ademco 685

Ademco 685 Digital Alarm Receiver

the stealth S-100 chassis

Provision for battery backup

This alarm is built on a S-100 Chassis. It comes with a California Computer Systems (CCS) 2810 2 / 4 mhz switchable Z80 CPU. It doesn't have the CMOS EPROM installed however I burnt one from a copy of my existing CCS system, changed a couple jumpers and there we go a nice auto bauding serial console with a ROM Monitor. Get a feel for the size of the enclosure for this if not rack mounted. This is the chassis after I striped it of an unnecessary wiring harness. The chassis removed from the enclosure weights in at 20 pounds where a CompuPro desktop weights 32 pounds. I measured the DC supply at 9.18, 14.22 and -15.8 I see a bunch on ePay and have seen them on Craigslist too.

I installed a set of CCS boards and successfully booted from 8" FDD at both 2 and 4 mhz. I tried a CompuPro set without success. Interesting that I haven't made the CCS board set work on the CompuPro chassis. Buss termination needs more experimentation.

I've cut away the wire harness. There is a single purple wire to leave between the aluminum supply within the main supply that goes to the PCB mounted against the outer wall of the chassis.

Leave this purple wire.

A standard rack mount plate can easily replace the front panel. Drill 4our holes to attach to chassis.