Joe's AMI S6800 System web page

Created 10/2/2003

This page was created to display the AMI S6800 computer that I recently bought in hopes that someone can provide more information about it. Based on the date codes on the ICs this computer dates from about 1976 or 1977 and I'd like to get it running again. I bought it from the son of an early member of the Home Brew Computer club. The computer is based on an AMI S6800 Prototyping card that he bought as part of a group purchase through the HBCC. The original owner built most of the computer from scratch and I'm told that the boards were bought as bare boards and the owners had to install all the ICs themselves. This system originally ran an operating system called Flex. I have searched the Flex archives and several members mentioned that they got their start with Flex using computers built from AMI Prototyping cards that they bought as part of a group purchase. Most likely they were part of the same group purchase. If anyone has more details about the purchase I would like to hear from you.

I did get an original box with the system. Here is a picture of it. One the end flap it says "EVK 100 8074863".

I was very lucky with this system. I got three CPU cards with it! Two of them (picture 1, 2) have 6800 CPUs. The third one has a 6809 CPU and has been heavy modified! The CPUs are the large IC near the upper left corner. On the first and third boards it's a gold and purple package. On the second board it's a plastic package. Note that the CPU baords have a built in EPROM burner. It's the red socket on the second) CPU card. In additon, there's also a socket for burning EPROMs on the back of the chassis. I haven't had time to study them yet but I think they're set up to burn 2708 EPROMs.

Here is a picture of the chassis and here is a picture of the back of the chassis. At first I thought the chassis was home made but after looking at it I think it is factory made. if it is home made then the builder did an excellant job! Inside the chassis is a backplane made with a printed circuit board. The backplane is obviously factory made and the fit between it and the chassis is another thing that makes me think that the chassis isn't homemade. BTW I didn't get the power supply for the system so I have to figure out what it needs and build one before I can try to power it up.

Besides the CPU boards I got two 16k memory boards (picture 1, 2). Both boards use AMD AM91L02 (1k x 1?) IC memories and were made by Davis Laboratories in Santa Clara, California. Does anyone have any information on them?

The system also has a floppy drive controller board (picture). It's hand made and based on a wire wrap board that's also made by Davis Laboratories. Does anyone have any information about this board? I'm hoping that it's based on a published design and that I can get information about it. Otherwise it's going to be a bear to reverse engineer. I was told that this system orignally had 8" floppy drives and I even got an 8" floppy disk that's supposed to have come from this system and is supposed to have Flex installed on it. But the drive and cables were thrown away long ago so I'm going to have to figure out the connections, jumper settings, drive type and other basic information before I have a hope of getting the system working again. The controller does use a 1791 controller IC so that does make things a bit easier.

Finally, the last card in the system is an unknown (picture). I suspect that it's for the slot marked "kludge" (it's written in pencil so it's hard to see in the photo) on the chassis but I have no idea what it's for and I haven't had time to study it yet. It's also hand made and also based on a wire wrap board made by Davis Laboratories. Hopefully it's also based on a published design and someone out there has information about it. It has an IC on that's marked FCM7002. I have never seen one before and NO idea what it is. It also has a XC6820 and six 6810s on it. There are also four EPROMs on it. I'll have to pull off the stickers to see what type they are but just as a guess I'd say that they're 1702s. There are also two large ICs in the center of the board. Again I'll have to pull off the sticker to id them.

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