Hi Tim, the first few models were all socketed, we moved to soldered both for reliability, and because volumes went up and we switched to automated board filling and wave soldering equipment.Thanks for all the dip settings, I will give them a try.
Funny that one of your CPU cards is only 9 away from mine in its serial number. Mines 1563. Are the IC’s socketed?. The later FDC controller i have, the chps a soldered directly into the PCB.
Interesting about the IBM drives, Would a hard sector floppy work in them? Not sure of the actual differences in the drives between soft and hard sector.
Do you know what drive’s were fitted originally? There’s a good chance I might have some.
The hard sector floppies were always going to be a high hurdle to get over. Reading some of the posts from the North Star forums, there are a few solutions that I could explore. But I’m putting this off until I know the rest of the system is working.
As to what i’m going to do next.
I have come to the conclusion that I need to be able to easily plug in a logic analyser to the backplane. I therefore going to make a PCB up to facilitate that.
I need to go do a better job on the disassembly of the eproms on the FDCs and get us much info from that as possible. For example port addresses, and how it inserts boot code into the rest of the system.
I also need a better understanding of the dip switches, especially on the memory cards.
That should keep me going for a few months.
If you come across any more info i would really appreciate it. Likewise i will do the same.
Regards Tim
IBM drives I'm 99% sure would just sneer ate hard-sectored media - I don't think IBM ever went near hard sectored 5-1/4", though I think they did some early hard-sectored 8".
I may have a spare hard-sectored drive somewhere; I'll know in a week or two... The timing of all this is good. My wife has just confirmed that we have got a skip coming tomorrow to get rid of a load of junk in the garage that currently prevents me from being able to find a lot of the good stuff. I think in the early days we used Tandon then Teac.
If you try the later FDC, that is more likely support soft-sectored media on the IBM drives.
S100 extender cards used to be common. The card would often be a bit taller than a normal S100 card. The bottom had the normal S100 connector gold lands. The top would have an S100 edge socket.
Tracks ran from one to the other (often with some layout artefacts to avoid inductive coupling between tracks on opposite sides running parallel too long - though I get the impression this is an area you know a lot more about than me.,
Extending that design to include pins near the top on the board for connecting a logic analyser might be useful.
This weekend, I'll try starting to contact some old friends who may have more material than I. By the time I left Comart/Kode I'd been moved from technical to being the marketing manager, so when things kind of imploded, I didn't think to get any manuals - just did a deal with the CEO on a couple of boxes of kit from the rubbish bin.
Not to be nosy, but whereabouts are you? I'm Swindon based (Comart merged with KI and so moved from St Neots to Swindon).
As well as the kit I've mentioned, I have some FDDs, two of the old HDDs (I think) and what was at last sight a working 8086 C-DOS 86 system. Though I'm terrified to apply power to the old caps - I could be interested in trading some assistance in that area for some spare cards/drives etc., if that's of interest to you.
In the meantime if you think any of those cards would be a useful loan, just let me know and we'll work out a way of getting them to you.
Best regards
Dave.