I got an interesting 6502-based device at a university surplus sale. I think it's called a "More M7" and it's by Observational Systems Inc. from Seattle, WA. It seems it belonged to the psychology department.

Here are some photos: http://enosys.ath.cx/6502device/

On the front panel it has 24 keys, 8 toggle switches and a 4:2 digit 7 segment LCD display. The key labels and LCD make it appear that it should be running some sort of monitor with the ability to view and edit memory contents, enter breakpoints and so on.

One side of the box has 9 and 15 pin female sub-D connectors and two 1/8" mono jacks. The connectors are labelled host, keyboard, audio in and audio out. The other side had a cut off power cord which I replaced. I used that to supply +5V because that seems to be the only choice judging by the chips that are used.

I tried to figure out what to do with this, but it doesn't work reliably, and perhaps I can't figure it out. I can push reset, get it to start displaying stuff on the LCD and type in hex. It usually crashes soon and unpredictably though.

The main board has an NMOS 6502 ("MOS MPS 6502"), two Synertek "S10411 072679" 40 pin DIP chips I can't identify, a 2532 (4k*8) EPROM, and 10 NEC D444C-6514 (1k*4) SRAM, some 74LS TTL, a 565 timer and an LM311 comparator.

There is also a front panel board with 4000 series CMOS for the keys and LCD and a power board with a 5V to 12V converter, another LM311 and an LM747 dual opamp.

I'd like to get this running at some point. Has anybody dealt with one of these before? I'd like to be able to download code to it. According to the key labels this should be already possible. Otherwise I guess I'd have to map out some I/O lines and write a new EPROM. Any advice?

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Boris

> Otherwise I guess I'd have to map out some I/O lines and write a new EPROM. Any advice?

It sounds like it's old enough that the EPROM could be partially erased. I think they're guaranteed to hold their info reliably for ten years and you usually get closer to 20 out of them; but to keep something alive for a long time it's good to periodically copy the EPROM for back up and reprogram the original with the same material. No need to erase first-- just refresh the data.

In case it's not the EPROM-- does anything else seem to make it crash or change behavior? like flexing the board? Sometimes IC sockets will develop a bad connection, and simply removing the IC and putting it back in a time or two will give a self-cleaning effect on the contact points and fix it.

Thanks! I unplugged and then plugged back in all the socketed ICs and moved the RAM around. It now doesn't seem to crash anymore but I still can't figure out how to use it. I don't think it's running a monitor.

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Boris

First of all, Id like to say Hi to everyone!!!! This is my first post on the forum, though I have visited the site since 2000.


The 2 ports that im wondering about are the keyboard and the host port. One thought could be that the keyboard port is for a external keyboard or mearly to output signals sent by the onboard keyboard.

The other port is a little more interesting. I was looking at the pictures, and I believe you can follow the traces the data on the port follow. I wouldn't be suprised if they lead to RS-232 chips. That port might be a serial interface, which should connect to some dumb terminal. This may have implications on the 5 volt supply you are using(possibly meaning that the it should accept 9 but the regulator drops it to 5 for the logic, however i have no way of knowing for sure, so don't try it unless you are sure you won't fry your board). I notice the capacitors on the cpu board, where do they lead(its hard to tell with the pictures) specifically im referring to the the capacitors which or on the top edge of the board. There were chips which could fake the 9 volts required with fancy use of resistors and capicitors. Also, I believe on the Cromemco C-10(or was it the Cromix minicomputer), the serial port was called host or was referenced as such in the manual.

I don't know if it will be of any help, but if you follow those traces and see where they go on the card and use a o-scope to see the signals coming out of the ports, you will probably get your answer.

--Michael Moran