Do look at the power supplies. I didn't mean to say that the unit had a switch to select 240/120, I meant that the transformers, usually, had 4 primary connections. These would be wired in parallel or series for 2 different voltages. They did use a lot of different power supply manufactures so your machine may be different.
Well. This a 8 year old thread, but it isn't much discussed on the Intellec 8 systems so I just continue here. I just started to get my little Intellec 8 working. I bought it three decades ago at a flea market for around 10 euros.
I have dumped the firmware and taken photos of all the cards. The firmware and photos: https://drive.google.com/drive/folders/1NOUxgHN0HNzZujf-OtU8pmPDZS40e1zJ?usp=share_link
Apart from the 8080 CPU card and the front panel controller It has two 4k RAM boards, one 4k PROM board and two I/O boards. One interesting thing is that someone upgraded the EPROM programmer to handle 2704 and 2708 instead of 1702. The old PROM programmer card is still sitting in the machine but not used.
This machine is not switchable to 230VAC so there is an external step-down transformer. It has s/n 178. Most of the ICs in it has date codes form 1973 or 1974. Except for the CPU which is dated 1979 so I wonder if that got replaced at some point in time?
My next step is to check out the PSUs. Rather difficult to get them out of the chassis actually. Then we'll see if it does something when the power is applied.
Years ago when I worked for Intel, My room mate had purchase a bunch of pieces from Intel's scrap sale ( something they don't do now days ). He put together enough pieces to make a working series II machine. We had a problem to solve, the disk drive we got for it, was 50 hz and 220V ( 8 inch drive ). I found a transformer used for one on the SDK setups and it had a three tap primary transformer. I used that as an auto transformer to get 220V from 110V. For the frequency difference I used a file and modified the motor pulley to the right speed for 60 Hz. It required also elongating the mounts for the motor. As I recall, the motor pulley and fly wheel were a set to 50/60. Anyway, we got a working series II computer running with all scrap parts ( most all the boards required some repair parts ). I'm trying to but a date on that but it was in the 1980's sometime. For the scrap stuff,we had to sign an agreement to never sell any of the stuff.I checked the PSUs. They are quite "hard coded" for 115 VAC. One single winding on the primary side. No big deal. I have the step down transformer so it solves it.
While starting to check the PSU I discovered that the crowbar for 5V triggered at 8.5V. I tuned it to trigger at 5.7V instead.
I checked the dumped firmware and could find a string "8080 v4.0" in there and then also some assembly mnemonic strings.
I think I will just run standalone software on this machine. Not any OS. I was thinking I can load the micro-chess or the Altair 4k BASIC. After all it only have 8 k memory. Not much. Would CP/M even run in 8k?
Hi Jon,The controller has a 100-pin interface which may - or may not - correspond to the arrangement of the Intellec 8 backplane. The same document includes schematic drawings.
It took me a while to find the right link for the rom dump, but eventually I got it. Here's my quick disassembly, and yes that stuff is clearly for a disassembler.Turns out Mattis has version 4.0 of the MON-80 monitor, plus some kind of disassembler. I'm not aware V4.0 is available elsewhere. If anyone follows up on understanding the disassembled disassembler, or further disassembling the V4.0 monitor, please contact me so I can add that information to my Web page.
Thanks Bruce, good to hear from you. I sent Mattis a disassembly some days ago, of the disassembler and what seems to be a "V4.0" of Intel's MON-80. (It's possible someone modified a 3.0 or earlier and called it "V4.0".) And that disassembly is on my MON-80 Web page with other versions of MON-80. The disassembler part is not part of the MON-80 code but calls to it (presumably for I/O). I also sent Roland, privately, some quick disassembly of his monitor code., which is V2.0 of MON-80; his ROMs have yet other code not disassembled.It took me a while to find the right link for the rom dump, but eventually I got it. Here's my quick disassembly, and yes that stuff is clearly for a disassembler.
Yes, like mine that I used, which is a manually controlled tracing disassembler (links in sig). Except that when I tried to get it to generate Intel mnemonics, I realized that I had never actually made it (or its predecessors) generate Intel mnemonics! I still have testing on my to-do list for some edge cases, but it took me a couple of hours to add a new opcode table.In due course Bill Beech and also I, will release versions of Bill's disassembler. No big hurry, there's lots of 8080 disassemblers around. It's a good exercise to write one or modify one. - regards Herb