Joe's Intel MDS-800 Microcomputer Development System web page

Created 6/20/2003

This page still under construction

Here is my first Intel MDS-800. This system was used for many years to develop software and hardware for a medical system and included dual 8 inch double density disk drives, a whopping 32k of RAM, a (non-Intel) EPROM programmer and an In-Circuit Emulator for the 8080 CPU. Here is what it looked like when it arrived. After unpacking everything and examining it, here's what I got: First I spotted a really odd looking card. (Yes I know it looks like it's upside down in the photo. But that's the way that it mounts in the computer so that's the way that it's shown as it is.) It turned out to be a Zendex model 908 EPROM programmer card. It's a Multibus card but it's taller than normal and is designed to stick out of the top of the chassis (that probably explains why I didn't get a top cover with this machine). Along the top of the card it has 8 ZIF sockets for EPROMs. It can program 8 EPROMs (2716, 2732 or 2732A) at one time. BUT The really interesting feature is that you can also use it as a standalone programmer! You can take it out of the chassis and connect it to the computer via RS-232, connect a 5V power supply and operate it that way. I did get the software and manuals for it too :-)

Next I checked the chassis. Here's a picture of it with the top cover removed. The left most circuit board is the Front Panel Controller board. This is the card that controls the front panel controls located on the front of the CPU. Note the early white ceramic 1702 EPROM on it. The die isn't even straight inside the package. That's because the first EPROMs were hand assembled.

The second card from the left was a standard CPU card with a nice early white ceramic 8080 CPU

The third and forth cards are standard 16k RAM cards The next card is a Monitor board with a ceramic 1702 EPROM containing version 2.0 of the monitor program and also two ceramic 8251s. This card also handles the communications with the standard ports. The ports are as follows; (top) Prom Programmer, CRT (terminal), Paper tape reader and (bottom) disk drive, LPT (line printer), TTY (terminal) and Paper Tape Punch. Here is a picture of the back of the CPU chassis showing the various ports.

The next six slots are empty. The next pair of cars are In-Circuit Emulator board and the 8080 Trace board for the 8080 Emulator pod. The ICE board has another one of those white ceramic 8080s on it.

Next there is one more empty slot. The next two cards are the iSBC 202 Double Density floppy drive controller cards. The left one is the Floppy Drive Controller and the Floppy Drive Channel board for the 8 inch floppy drives. Note that this system uses CDC (Control Data Corporation) drives. These are unusual, most on the Intel MDSs used Shugart 800 or 801 floppy drives. The CDC drives don't use the standard floppy drive controller but use one designed specifically for the CDC drives, note the name CDC on the controller card. Here is peek inside the drive enclosure at the floppy drives.

That's it for the circuit boards but for those that are interested here is a picture of the empty chassis. You can clearly see the Multibus sockets along the back. The smaller sockets in the front are Auxiliary connectors are used to connect circuit cards together for specific purposes. In this case they couple the two disk controller card together and the two In-Circuit Emulator cards together.

Ok enough of the foreplay. Here's a picture of the MDS in action.

The previous owner told me how much he enjoyed playing StarTrek on this machine and how much he missed it. I did some searching on the net and found a copy of the source code for an EARLY version of StarTrek that was written for the Intel MDS. I'm going to list here for anyone that's interested. If anyone compiles it and uses it, let me know what you think of it.

BTW I didn't get this with this MDS but it is for a Multibus system. It appears to be a relay controller card. It's made by Analog Devices and is model number LTS-1201. Can anyone provide more information about it?

I've enjoyed this system immensely and I'd like to do more with it. If anyone has any parts, peripherals, manuals or any other 800 or other MDS that they'd be willing to part with I'm be interested in hearing from you. I'm especially in need of manuals, the set that I got with this system are incomplete and are in rough shape. You can contact me at brigdonj@cbfl.rbr.comb but remove the Bees first! Sorry but I have to bugger the address to deal with the spammers.

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