View Full Version : Action Computer Enterprise, Inc. Discovery 500

March 20th, 2009, 08:27 PM
Here are some pictures of an ACE Discovery 500 Multiprocessor. It's a Z80 system (with multiple z80 chips on 2 processor/RAM cards.)



It's a later S-100 system with a non S-100 drive controller. The hard drive appears fried (unless screaming platter scratching sounds = great!). It was so bad my 2 year old daughter started to cry and my wife made me turn the thing off!


Anyway...The system will boot up and search for OS on the drive and then the hard drive. Anyone have the boot disk or installation software for one of these? Assuming that there is no software available, I am hoping that because it's an OEM-type system it'll be possible to build a working BIOS for it. Maybe it'll boot Xerox 820-II disks, wouldn't that be a hoot.

Action Computer Enterprise, Inc. did a lot of business in China, so there may be parts/software in Asia. There are additional links on my web site here:


March 20th, 2009, 09:34 PM
I just found some ads, confirming that the system was first available in Oct/November 1983, through the first months in 1984. After that, there are no ads, but that does not mean the system did not continue to be produced, especially for sale in China.



March 20th, 2009, 10:33 PM
Bill, I'll look around--I still may have a disk to an ACE Alloy 66. 8", SS MFM, 16x512 byte sectors per track according to my notes. Don't know if it'd work in your system, though.

March 21st, 2009, 05:15 AM
According to the ads (link above) the 500 is in some form compatible with CP/M, PC DOS, and Concurrent DOS. I *hope* the PROM does the BIOS work before reading disks, and loads some sort of universal bootstrap into memory so that it can read any kind of disk from this period. And I'd like mayo on that too. I am not holding my breath, but I do plan to try some random boot disks once I have determined that the system has a clean disk drive.

March 21st, 2009, 12:31 PM
Looking at the Alloy files, it seems that ACE mostly made their boxes out of commodity components and did very little other than the CPU cards themselves. For example, the Alloy66 uses a Tarbell disk controller. Your Discovery uses a DTC 520A ST412/floppy to SASI bridge. That should make your job much easier.

March 21st, 2009, 06:49 PM
Anyone have a CP/M Plus disk? I wonder if a Televideo CP/M boot disk will work..hmmm.

March 21st, 2009, 08:14 PM
Anyone have a CP/M Plus disk? I wonder if a Televideo CP/M boot disk will work..hmmm.

You'll still need a CBIOS that works with that system--the chances that any of the usual suspects will work is pretty close to nil.

However, the boot ROM has everything you need to know to write your own BIOS. It does console I/O and it obviously can do disk I/O. Dump it, disassemble, and go from there.

July 16th, 2010, 04:46 PM

I was just wondering what something like this is worth!?! I've been holding onto my Discovery 500 since about 1987. I got it at a garage sale from a retired electronics engineer. I have two Wyse-50 terminals for it. It boots up and runs great. I even compiled some simple programs with the CP/M C compiler on one of the Z-80 slave processors. I have extra cables and the original manuals and floppies, and even a spare hard drive for it that doesn't look like it's been used. It came with an original Centronix serial printer, with cables, extra ribbons, and manual.

Over all, the system seems to be in great condition. I just don't know what to do with it, since I know I'll never make the time to play around with it ever again. I've always kept it in my closet, protected by other boxes full of Commodore 8-bit stuff.

I sold an IMSAI 8080 w/8" floppy drives a few years back for $500, so that started the gears spinning in my head about what this system might be worth. Any ideas? Would eBay be a good place to list it, or do other vintage computer classifieds exist?


August 28th, 2010, 04:15 PM
haha what a blast from the past... i used to work at ace... it was a GREAT place to work until the chinese bought it... not that the chinese were bad... but nobody listened to us "kids" in the R&D department and the ibm pc network card pretty much matched the benefits of our much more expensive machines... i was the guy who built the final o/s and utility disk configurations that got sent out with our computers... wrote bios drivers and utils in c and asm... good times ;o)

http:// (http://www.freedomnetwork.com)

October 6th, 2010, 06:28 AM
I am still looking for a copy of an ACE Discovery 500 boot/util disk. I can supply the disks, a return mailer, etc. All you have to do is make the copy and mail it back...please?????

September 28th, 2016, 09:01 AM
I am still looking for a copy of an ACE Discovery 500 boot/util disk. I can supply the disks, a return mailer, etc. All you have to do is make the copy and mail it back...please?????

Did you ever find boot and utility disks? Check out the Discovery 500 page (http://retrowagon.org/wiki/index.php/Discovery_500) on my wiki. I recently came across a functional Discovery 500 with documentation and floppy masters. The HD was toast.

- Jeff

September 28th, 2016, 11:30 AM
sold a long time ago. nope.

October 10th, 2016, 11:21 AM
jhalbrecht - I have some ACE CPU slave boards. Please contact me c/o retrotechnology.com. There's no contact-you reference on your Wiki.

Herb Johnson