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SOL-20 memory map
- Thread starter guibrush
- Start date
Hugo Holden
Veteran Member
The old one way vs 2 way serial communications trap.
I drew up a diagram once of how to correctly set up the SOL serial interface, to a computer serial interface at least...I just have to find it !
I drew up a diagram once of how to correctly set up the SOL serial interface, to a computer serial interface at least...I just have to find it !
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Hugo Holden
Veteran Member
@all Many, many thanks for all your efforts helping me!
In the meantime, I've found the source of the problem: it's a chair-keyboard interface problem: me. You're going to laugh.
I was using the SERIAL to USB adaptor I pictured above, but it turns out to be a serial.... RS422 SERIAL ADAPTER. However, RS422 is only compatible with RS232 on the transmit side, not on the receive side. So I bought an RS232 adapter, and it works as it should. I'm sorry I've wasted your time :-(
So I was able to start the Xmodem transfer, the first part (around 45 KB) was transferred, then when I started writing for the first time, I got an error message (Write failure on track 0, sector 2) and the writing stopped. Has anyone come across the instructions for the Micro complex Phase Lock II floppy card, to find out if the dip switches are configured correctly? My floppy drive is a TEC FB-504, so 720K, I'm going to try another drive this evening.
It's encouraging, progress is being made
In the meantime, I've found the source of the problem: it's a chair-keyboard interface problem: me. You're going to laugh.
I was using the SERIAL to USB adaptor I pictured above, but it turns out to be a serial.... RS422 SERIAL ADAPTER. However, RS422 is only compatible with RS232 on the transmit side, not on the receive side. So I bought an RS232 adapter, and it works as it should. I'm sorry I've wasted your time :-(
So I was able to start the Xmodem transfer, the first part (around 45 KB) was transferred, then when I started writing for the first time, I got an error message (Write failure on track 0, sector 2) and the writing stopped. Has anyone come across the instructions for the Micro complex Phase Lock II floppy card, to find out if the dip switches are configured correctly? My floppy drive is a TEC FB-504, so 720K, I'm going to try another drive this evening.
It's encouraging, progress is being made
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Hugo Holden
Veteran Member
Possibly, your latest problem could be explained by bad media. When I first started out I got similar messages until I got some late manufacture 3M disks, these ones have the Olympic logo on the box. Maybe changing the drive will help.
When I set my system up I was so worried about getting it working the very first time, I used NOS drives, which were still sealed up in their box since 1984. Oddly though, one of about 6 drives turned out to be defective, with a failed Hitachi 74LS series IC, which was very unusual.
Of course, once you have established that a system works, if it fails later, it is fairly easy to find the cause, but, if it never worked in the first place, it is a whole other ball of wax. I got duplicate N* drive cards and IBM drives tested and ready, so if my system fails I can quickly substitute them in and find the basic location of the failure; controller card, drive unit, computer, which is a huge help in fault finding a broken system because it allows you to concentrate on the part of the circuit where the fault is.
All the S-100 disk driver cards like this have a phase lock servo system I would expect. Although the Microcomplex card is supposed or said to be a N* copy, it doesn't appear to have the same IC's or layout. It would be really helpful to have the manual, schematic & operating theory for this card. Fortunately the N* card was fairly well documented.
When I set my system up I was so worried about getting it working the very first time, I used NOS drives, which were still sealed up in their box since 1984. Oddly though, one of about 6 drives turned out to be defective, with a failed Hitachi 74LS series IC, which was very unusual.
Of course, once you have established that a system works, if it fails later, it is fairly easy to find the cause, but, if it never worked in the first place, it is a whole other ball of wax. I got duplicate N* drive cards and IBM drives tested and ready, so if my system fails I can quickly substitute them in and find the basic location of the failure; controller card, drive unit, computer, which is a huge help in fault finding a broken system because it allows you to concentrate on the part of the circuit where the fault is.
All the S-100 disk driver cards like this have a phase lock servo system I would expect. Although the Microcomplex card is supposed or said to be a N* copy, it doesn't appear to have the same IC's or layout. It would be really helpful to have the manual, schematic & operating theory for this card. Fortunately the N* card was fairly well documented.
Yes, you’re totally right. I’m not even sure that the controller board is working. I do have a chip that is a little to hot to my taste. But first I will check with another drive. I saw that the drive have to be terminated and that I have to put it in DS1. It can even be that I tested in DS0, I’m not sure anymore.
Attachments
Hugo Holden
Veteran Member
Gulp ! it looks like the fuse programmable 18S22 boot ROM might be installed backwards in the socket, unless they configured it that way from new. Check the actual pcb tracks and see where the + & - power supply pins go.
I think that part is the same as the DM or SN 74S470. Vcc pin 20, GND pin 10
And MMI 6309 as it says on the pcb:
www.electronicsurplus.com
When I bought spare PROMs for my N* card, to program them for my spare parts box, I was disappointed to find that some had already been programmed with other data (its a one way ticket) but the sellers did not know. Though one clue was, often programmed ones have a dot of paint on them.
I think that part is the same as the DM or SN 74S470. Vcc pin 20, GND pin 10
And MMI 6309 as it says on the pcb:
MMI - 6309-1J - MMI6309-1 - IC, memory. TTL 256 x 8 PROM Memory, 70nS Access. 20 Pin CDIP.
MMI Monolithic Memories - 6309-1J - MMI6309-1 - IC, Memory. Microcircuit Memory. TTL 256 x 8 PROM. Fuse-Programmable PROM. Access time: 70NS. 3 State. Supply Voltage: 5V. Package: 20 CDIP, DIL-20/IC Genuine MMI - New Old Stock -Never Used - Vintage MMI6309-1 Memory ICs. (Rare and Difficult IC to...
www.electronicsurplus.com
When I bought spare PROMs for my N* card, to program them for my spare parts box, I was disappointed to find that some had already been programmed with other data (its a one way ticket) but the sellers did not know. Though one clue was, often programmed ones have a dot of paint on them.
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Hugo Holden
Veteran Member
Actually, looking at the previous board image, there are other IC's that are turned around like that (in the area where the Crystal is) and the board white ink screen printing seems to agree they should be like that. So the IC probably is in the correct way around. Most manufacturers have them pointing the same way , but sometimes for pcb design convenience, they turn some around.
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the IC is in the right position, confirmed. but the IC is very hot. Fun fact : I removed it, and pctofloppy is still able to see the floppy drive when I select it. I assume that this is the boot rom and it's not needed at this time?
I have big stability problems when the Phase Lock II controller is installed into the SOL-20, the computer hang very often, sometimes I can't even launch a simple .ent file. Without the board the SOL-20 is much more stable. I assume then that the floppy controller is somehow defective. Because all chips are soldered I don't think that I will be able to repair it. Now the question is, if I want to buy another floppy controller board, does this one
work in the SOL-20? If not, does something else exist on the market nowadays, or do I need to buy a used one?
Thanks
I have big stability problems when the Phase Lock II controller is installed into the SOL-20, the computer hang very often, sometimes I can't even launch a simple .ent file. Without the board the SOL-20 is much more stable. I assume then that the floppy controller is somehow defective. Because all chips are soldered I don't think that I will be able to repair it. Now the question is, if I want to buy another floppy controller board, does this one
Thanks
deramp5113
Veteran Member
The FDC+ is not a good controller to use with the Sol-20. Any software that works with the FDC+ expects to be in an Altair with its typical console, printer, and serial I/O ports. These, in turn, are quite different than what’s in a Sol-20.
deramp5113
Veteran Member
Single density works just fine in the Sol, but the small capacity (<88K) can be very limiting.
deramp5113
Veteran Member
Hugo Holden
Veteran Member
I just went through my collection of S-100 cards and found that I have two spares of the N* double density board. Both have had all of their IC pins & sockets cleaned and checked and work well in my SOL-20.
These boards must be getting rarer these days as the single density ones appear a lot easier to get, probably because everyone wants the double density ones for SOLs.
I could be persuaded possibly to part with one, for the right price I guess, it would leave me with just the one spare card, which should probably be enough for fault finding. The single density cards on ebay seem to be priced around $200, but I doubt if any of the sellers know for sure that they are working, it takes a working SOL, a good disk drive, Mike's VSG and good soft sector disk media to find out!
In my search I also found that I have in my stocks the Matrox ALT-2480 S-100 board, which I think is probably pretty rare. It was the companion Text card to the ALT-256 graphics card.
These boards must be getting rarer these days as the single density ones appear a lot easier to get, probably because everyone wants the double density ones for SOLs.
I could be persuaded possibly to part with one, for the right price I guess, it would leave me with just the one spare card, which should probably be enough for fault finding. The single density cards on ebay seem to be priced around $200, but I doubt if any of the sellers know for sure that they are working, it takes a working SOL, a good disk drive, Mike's VSG and good soft sector disk media to find out!
In my search I also found that I have in my stocks the Matrox ALT-2480 S-100 board, which I think is probably pretty rare. It was the companion Text card to the ALT-256 graphics card.
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Many thanks Hugo for your offer. It’s very kind of you. I just want to investigate a little further to make sure that the controller board is the problem, and not the SOL-20 itself.
This morning I managed to make a complete transfer from a CP/M disk to my floppy drive. Obviously, it doesn't boot (logical, given how hot the ROM is, there's little chance of it still working), but the disk has been created correctly. However, I've noticed a curious behaviour: the xmodem transfer works fine on a cold machine, but after a few minutes, the transfer slows down considerably, until it stops at a few percent after about 10/15 minutes of use. I think my controller card must be interfering with the SOL-20 quite seriously, or the SOL- has a stability problem…. I don’t knowl When the computer is in this state, then loaded softwares in .ent format crash very often when launched, I have to power off the SOL-20 for some time, then it’s stable again (to test this, I launched some games in .ent format directly after the transfert failed, with a power off an on to empty the memory each time, and almost 3 games on 4 crash when executed, then I waited in power off mode about 15 min. and I launched all games that I have, about 20, without any single crash).
just to be sure: I can use the same 720k floppy drive on the DD controller and the SD controller, it’s the VSG that do the work, or the SD controller will require a specific drive? It can be that a friend of mine has a SD controller in his S100 machine, it could be a good test for me.
This morning I managed to make a complete transfer from a CP/M disk to my floppy drive. Obviously, it doesn't boot (logical, given how hot the ROM is, there's little chance of it still working), but the disk has been created correctly. However, I've noticed a curious behaviour: the xmodem transfer works fine on a cold machine, but after a few minutes, the transfer slows down considerably, until it stops at a few percent after about 10/15 minutes of use. I think my controller card must be interfering with the SOL-20 quite seriously, or the SOL- has a stability problem…. I don’t knowl When the computer is in this state, then loaded softwares in .ent format crash very often when launched, I have to power off the SOL-20 for some time, then it’s stable again (to test this, I launched some games in .ent format directly after the transfert failed, with a power off an on to empty the memory each time, and almost 3 games on 4 crash when executed, then I waited in power off mode about 15 min. and I launched all games that I have, about 20, without any single crash).
just to be sure: I can use the same 720k floppy drive on the DD controller and the SD controller, it’s the VSG that do the work, or the SD controller will require a specific drive? It can be that a friend of mine has a SD controller in his S100 machine, it could be a good test for me.
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Hugo Holden
Veteran Member
Sounds like a good plan. I have not played around with the SD controller, likely though, it would be simpler and a better bet than the DD controller, especially if the programs you use are not too large.