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View Full Version : The Incoterm SPD 10/20



jqsmith
August 16th, 2015, 09:44 AM
I am attempting to get my first computer running again and will post some videos along the way. It has been in storage and after I pulled out two IBMs, I thought I would try to get this system running. A little info on this computer can be found here:

http://www.datormuseum.se/peripherals/terminals/incoterm-spd-20-20

jqsmith
August 16th, 2015, 12:00 PM
First video showing the storage and circuit boards.

https://www.youtube.com/watch?v=CDijWQ91JWQ&feature=youtu.be

MattisLind
August 16th, 2015, 01:45 PM
I see that you found my page! I haven't done much on this machine yet. Last time I ran it was probably in the early 80ies.

It would be nice if there were some technical manuals around. What kind of documentation do you have?

I am looking forward to to view part 2!

jqsmith
August 16th, 2015, 04:02 PM
I'm sorry to say I do not have any documentation for it. It was available back when I bought it but back then I had no way to copy it. I wrote quite a bit of code for it and assuming I can get it running will give some demonstrations of it's power. In the mean time.... Enjoy part 2

https://www.youtube.com/watch?v=EDvkmwdu0Jo
(https://www.youtube.com/watch?v=EDvkmwdu0Johttp://)

jqsmith
August 16th, 2015, 04:07 PM
There was a trick I am trying to remember. If you turn on the computer and it does not boot, you can press the boot switch on the drive. Some times this did not work. In that case, there is a red push button switch on the left side of the computer. Pushing this causes a reset and you can then enter code into the code from the keyboard. I think it took the lower nibble of each ASCII character. There was a CIO (???) call that forced a reboot. Maybe CIO 7,7? I can't remember the key strokes for it. Does any of the documentation you have mention this?

MattisLind
August 16th, 2015, 11:02 PM
I need to check what documentation I have. It has been a long time so I am not sure where everything has been stored. Until now I have only found some documents on SPD/DOS and documents for some IBM terminal emulator. I remember that there were floppy disks with this machine, but I haven't found them yet, unfortunately. But there are two disks sitting in the floppy drives.

Can you check if your board setup matches the setup of my machine?

jqsmith
August 17th, 2015, 04:48 AM
I need to check what documentation I have. It has been a long time so I am not sure where everything has been stored. Until now I have only found some documents on SPD/DOS and documents for some IBM terminal emulator. I remember that there were floppy disks with this machine, but I haven't found them yet, unfortunately. But there are two disks sitting in the floppy drives.

Can you check if your board setup matches the setup of my machine?

There are some differences. The 10/20 has 4K (I think) of core memory. This was shared with the video, maybe 50/50. Very hazy on the amount of memory but you could use the video area to store your programs in. Then a lot of disk swapping. It was a nightmare, all in assembler. However, there was BASIC for it. To run it, you needed more memory than what the 10/20 had. There was a new model that had this added memory. I am not sure that this was not your system. Other boards, like the keyboard and disk controllers are a lot different. Your system is appears to be newer than mine.

Went to buy the new transistor for the power supply and it was over $20 (US). I suspect this is because of it's age and package style. Ended up with what should be a better part for $0.70/ea. The part I have in it to test is not rated to the voltage it needs so I have not yet ran it from the line voltage. It's close.

MattisLind
August 17th, 2015, 02:24 PM
I thought that this board was the video board. The memory chips are AFAIK 2k x 1 SRAM chips which would give a 80 x25 character display. Then there is something that looks like a MOSTEK chargen ROM. Do you have such a board in your machine?

Most boards in my machine has chips manufactured in 1976. But the core memory has chips marked 72. Maybe they moved the display memory to a separate board later? It is really pity that the field engineering bible seems to be lost. It would be a nightmare to trace all those boards to sort out how it works.

http://i.imgur.com/RaGrGXD.jpg

jqsmith
August 17th, 2015, 04:03 PM
On my system, the video board is one of the large ones. It is in the furthest back slot. There are two large PROMs on it for the character generator. There were two boards available. One was text only and the other had graphics support. Your system may be different. Check the wiring where this card it plugged in. On mine, all of the side boards are peripherals and have connectors on the bottom of the machine. There is a keyboard, disk, printer and serial communication board in mine.

I had a friend who had all of the documents for it. They were attempting to make a memory board for it at one time but I am not sure what ever happened.

25920

jqsmith
August 19th, 2015, 05:10 PM
Transistors made it in today and I have gone ahead and replaced it. The rest of the supply looks good but I need to get it on an auto transformer and really check it out before I install it.

MattisLind
August 21st, 2015, 12:45 AM
Comparing the RMTU (that is what the board is called by the Incoterm Alumni people) is interesting. Mine has five MOSTEK chips which is what I believe RAM chips. Then two MMI ROM chips. So if this is in fact is the display board, what use is the other board with Intersil memory chips? A secondary display?

Do you have high res photos of the boards in your machine? Would be interesting to compare.

jqsmith
August 22nd, 2015, 03:10 PM
I can take a few. I would have guessed the board in your picture was the added RAM to support BASIC.

Does your system still boot?

jqsmith
August 22nd, 2015, 04:19 PM
https://www.youtube.com/watch?v=zP9gHaeIVzc&feature=youtu.be
(https://www.youtube.com/watch?v=zP9gHaeIVzc&feature=youtu.be)

MattisLind
August 23rd, 2015, 04:11 AM
Does your system still boot?

No, haven't tried. Need to go through the same procedure you are doing testing the PSU etc.

MattisLind
August 25th, 2015, 11:23 AM
I had a mail conversation with, John, an ex Incoterm employee. He think my machine in fact is a 10/25 because of the board with Intersil memory chips. The 10/25 used RAM for display where the 10/20 used the core memory for display as you mentioned earlier.

Unfortunately he has no documentation for it, but some spare parts.