Trying to boot a Kontron PSI-80 with single sided floppy drives

    Hi all,


    With a friend we are restoring a Kontron PSI-80 machine, and we got to a point where it is ready to boot. However, as this is a machine with the FD-1771 floppy controller (without a head-select signal), not the NEC 765, it seems impossible to do a successful boot using FlashFloppy with the double-sided images available at the (otherwise excellent and extremely helpful) oldcomputers.dyndns.org site.


    Any help would be greatly appreciated.


    Peter

    Nice and very interesting but please can you tell more about your problem.


    Have you some pictures and maybe dumped the roms'. Even I'm when the system was build and what floppy disk drives where included.

    Kontron used for some of the PSI80 models 100tpi disk drives where no disk images are available today.


    Are there some real floppy drives available ?

    Mit freundlichen Grüßen


    fritz

    So you have a 100tpi floppy drive. For such a system with bad diskdrives a Teac FD55 F was used to boot from an images.




    You have an older PSI-80 as in the rom is the BOS (Basis-Operating-System) and maybe it can only boot from a SSDD floppy disk.

    Sadly there is no Single Sided bootimage available as I don't know if the 'BOS' will boot with Double Sided Images.


    For the BOS Prompt you have to type 'K' and then 'ENTER'




    Some similar posts:


    Beitrag
    RE: Suche Boot Diskette für Kontron PSI 80
    MOD I oder MODII? Ich vermute aus eigener Erfahrung MOD II, und dafür brauchst Du 100 TPI Disketten (die ich auch nicht habe). Von den 96 TPI Disketten kann ich ein Image machen, es aber nicht testen, weil mein Kontron kaputt ist. Es sollte möglich sein, ein 96 TPI Laufwerk einzubauen und darüber dann zu booten und dann mit dem anderen (100 TPI) Laufwerk eine Kopie der Diskette zu machen. Das war zumindest mein Plan, bei dem mir aufgefallen ist, das mein Disk-interface massiv beschädigt ist…
    Joe_IBM


    Beitrag
    RE: Bezugsquelle für Ersatzteile (Motor)
    (Zitat von Toshi)

    Genau das habe ich gemacht. War aber nicht einfach, das Auseinanderbauen ging ja noch, aber das dann wieder zusammen zu setzen hat mich an meine feinmotorischen Grenzen gebracht. Besonders das Einsetzen der Kohlen und der Federn hat mich fast zum Wahnsinn getrieben. Wie weit so ein kleine Feder doch wegspringen kann...
    Lohn der Mühe: der Motor läuft wieder, und die Stroboskopscheibe zeigt ein schönes stehendes Muster. Disketten laden will der Kontron aber immer noch nicht.…
    Joe_IBM




    deramp.com



    Just for information only.


    The Kontron PSI-80/98 is emulated in MAME and the making of emulation will be find there:

    Kontron PSI98
    This is another Z80 luggable machine from the 1980's. Its less powerful but essentially similar sibling is the more common Kontron PSI80. Both machines are…
    forums.bannister.org


    https://archive.org/download/mame-merged/mame-merged/psi98.zip

    Mit freundlichen Grüßen


    fritz

    Thank you for your interest. Unfortunately my 486 computer I used to write images to floppy disks failed to access the drive (I tried several controllers and also tried to replace the floppy drive itself). I also tried Gotek/FlashFloppy, but it seemed that the Kontron needs a drive ready signal. And on the top of all, the keyboard started to get unresponsive, so I have to replace the foam pads :)


    But I have not given up yet, next weekend I will try to connect one of the drives directly to Greaseweazle and try to manufacture a boot floppy that way.

    Zitat von schp

    but it seemed that the Kontron needs a drive ready

    Mostly on CP/M time the Drive Ready was the default. Disk Change came with the IBM PC on the PC floppy drives.

    There where some drives with Ready/DiskChange jumpers before they only made them for IBM AT compatibility use and removed mostly all jumpers.

    You can search for using modern drives on cpc amstrad / atari / amiga and will find a lot of informations.


    Here are some Links:

    Jope's drive modification page

    Amiga - PC-Floppies umbauen

    Let HD 5,25" FDDs operate at 300 rpm instead of 360 rpm


    Even you may tell us what floppy drive you like to use.



    from the micropolis_1015_1016_maintenance_manual_dec79.pdf, but mostly all from that time use the Drive Ready signal.

    Mit freundlichen Grüßen


    fritz

    Thank you very much again for the information! I will make another attempt at this weekend to boot the machine. As for the floppy drive, it would be nice to use a Gotek (I will try to add a switch for the Drive Ready signal on the adapter board connecting the Gotek with the Kontron floppy cable), but it is a great idea to try to use a regular 3.5" drive with the Drive Ready modification!

    Hi Peter,


    since a few days/weeks I am working on a PSI 80.

    I though I can give you some good tips. But I read your first post and the usage of the WD177x floppy controller. And now I thing I can't help.


    I will tell you my experience with the 765 chip.

    For the READY signal you can set a jumper to activate it permanently. But first check the schematic and PCB, it's different.

    Also the other 2 jumpers on the floppy interface, check if the schematic and pcb are equal. In my case it is not and one connections are additional.


    Perhaps you check if only the WD177x is changed against the 765 and the rest is nearly the same. The signals on the connector should be the same, also the open collector drivers.


    The next problem I see: Which floppy images do you use?

    If you are using the images from oldcomputers.dyndns.org and this images use the 765 controller you always will have a problem.


    BTW, if you use the Gotek with flashfloppy, isn't there a config option to select the READY to pin 6? I am not shure.


    Have fun

    Florian

    ;------------------------------------
    ;----- ENABLE NMI INTERRUPTS
    (aus: IBM BIOS Source Listing)

    Hi Florian,


    Thank you very much for the information! I no longer know if I should be happy to own the older version of the PSI-80 or not :) I am surprised that your machine also does not match the schematics, it is strange that they manufactured so many variants of this machine.


    I saw some jumpers on the motherboard, I will definitely check if they are related to the READY signal or not.


    Hopefully the BIOS routines are present in one of the EPROMs (I have to disassemble them first), if not, then you might be well right, and the disk images available won't be working in their original form.


    I checked the FlashFloppy documentation, and it says that pin 6 is not connected, but I will check it again (maybe I misread the pin numbering). As I tried to use the Gotek with a small adapter board, it would not be that difficult to set an active READY signal.


    Peter

    Zitat von schp

    I am surprised that your machine also does not match the schematics, it is strange that they manufactured so many variants of this machine.

    No, no, the differences are not so important.

    2 times the A and B position of the jumpers differ to the printing on the pcb. Not dramaticaly but this is a simple reason for failures.

    And there is an additional connection from the head load driver to the floppy connector. Maybe it is made by hand on the solder side which i can't see.


    But before you configure the jumpers check if there are correct connected.

    ;------------------------------------
    ;----- ENABLE NMI INTERRUPTS
    (aus: IBM BIOS Source Listing)

    Only in German language.


    fishermansfriendtoo has just read :thumbup: a lot of SSSD floppydisks from a PSI80 with Micropolis 100tpi drives he has gotten from @nalkem .


    I believe he will tell us what he did to get the system running again when he finished the work and can relax.

    For your testing I added the KOS4 system images from fishermansfriendtoo who did a good job - I like it.