03/30/11: 2 disk controllers in the MPI ?? by Charlie, | Category: General | 17 comments - (Comments are closed)

2 disk controllers in the MPI ??

Long story short… (I’ll try anyway)

I wanted to order a DriveWire cable and a rompak with HDB-DOS from cloud-9.

They do not have any more rompaks. So I purchased just HDB-DOS rom and I will use it in my FD502 controller.

However, I also want to use my FD501 controller hooked up to my dual floppys. I want to be able to select on the MPI ,  4 to use real floppy drives, or 3 to use HDB-DOS.

So last night I put both controllers in the MPI and was able to switch between them with no troubles and everything seemed to work great. Of course I don’t have the HDB-DOS yet in the FD502, just the RSDOS it came with.

So it seems to work fine but is there any issue with having 2 disk controllers in the MPI?

One with RSDOS on actual drives and the other with HDB-DOS.


17 comments to 2 disk controllers in the MPI ??

  • sc

    Sounds a little dubious, both of your disk controllers are operated via the same I/O addresses, as I understand it the switch on the MPI will only choose which ROM is loaded at startup… and that switch should be moved while COCO/etc is powered up.

    There is also no need to switch: use your single controller with HDB-DOS, with physical drives attached. If you want to use drivewire images, choose your drive numbers as always.

    If you then want to use your first two physical drives (for example), just enter DRIVE OFF 1, and this will tell HDB-DOS to consider drives 0 and 1 physical disks. Entering DRIVE ON will restore all drive numbers to drivewire images.

    Won’t that give you enough “switching” ability?

  • sc

    Oh, sorry, what I meant to say above is the MPI switch should *not* be moved when system powered up, unless I’m mistaken?

    • As I was discussing with Mark at C9 the other day, it is normal to move the MPI switch under certain circumstances (ex: using a SuperIDE in slot 3 w/a FDC in slot 4 – booting to 3 and moving to 4 allows use of the floppies).

      In this instance, as RG said, there’s no reason to use 2 controllers, which negates the reason for moving the switch.

  • I wouldn’t move the switch while it was on. :-)

    Well, like I said it was working just fine. I had the 501 attached to the drives in slot 4 and 502 in slot 3.

    With 4 selected, i was able to boot Nitros9, load games, format disks, everything.

    Shut down, move the switch to 3 and the coco would start up but the drives didn’t work because it the 502 was selected.

    Still, if it is as easy as typing DRIVE OFF to have it function like normal attached drives, I will probably just do that. As long as Everything works. Plus I wouldn’t even need the multipak interface. I’ll post back the results when I get the ROM.

    Thanks for the reply!

  • I should have added above that with the switch at 3, if I moved the floppy cable over to the 502 in slot 3, then the drives worked off the 502 controller.

    Is it just that both controllers are working at the same time?
    I do have a second set of drives I can hook up to see if drive 0 lights up on both controllers at the same time…..

  • wow just realized they are not working at the same time because there was no activity from the 501 when the 502 was selected. Well, the rom will be here in a couple days, I’ll know then.

  • Robert Gault

    There is no need to use two floppy controllers because HDBDOS and Drivewire can address both the 4 Drivewire and the 4 floppy drives with one controller.

    If your intent is to BACKUP or COPY under Disk Basic from a floppy to a Drivewire disk, that also can be done with a single disk controller.
    Specify if you are using a Coco3 with 512K or a different system. If you have this, a RAM disk can be used as an intermediary between hardware and Drivewire. If you don’t have that system, then on Drivewire slot 0 use drive numbers above 3 to copy from/to a floppy. Then turn off the floppies (DRIVE ON) to copy from the high Drivewire # to 0 in slot 0.
    You can then transfer from the large Drivewire image to a normal sized image with emulators.

    • Hi Robert!

      Thanks for the info. At first I wanted 2 separate disk controllers to keep the system “stock” when using floppies.
      I have no need to transfer between DW and floppies because I can do all of that work on a PC with a 360K drive. I thought I would just switch to the DW rompak when I wanted to use DW.
      Cloud-9 doesn’t sell rompaks for DW anymore is the reason I am asking if using a 502 controller in its place would cause any ill effects. (being in the MPI with a 501 also)

      If it is as simple as DRIVE OFF to get the coco to work as “stock” with my floppy drives, and there are no compatibility issues with HDB-DOS and the thing I do with my coco3 (play games, lots and lots of games) then I will just use my 502 controller with it. :-)


      • Robert Gault

        Actually if you only occasionally need to use Drivewire and use a Coco3, you could save the ROM code on disk and LOADM it as needed without requiring the HDBDOS ROM. You could probably do the same thing with a Coco1 or 2 in all RAM mode but I have not tested that.

        On my system, I’ve altered the Drivewire.ROM code so it offset loads. Once loaded I LOADM”COPY”:EXEC (a small ml routine I wrote) which moves the ROM to $C000-$DFFF and jumps to $C002.

    • Hi Robert. I got my drivewire running and it seems to work good. I have a cc3 with 512k. I did what you said for backing up an RSDOS floppy. DRIVE OFF, BACKUP 0 TO 4, DRIVE ON, BACKUP 4 TO 0. It works but the image size on the PC is over 700K. Is there another way to back up to a normal 157K DSK image?

      Also, is there a Win Imgtool.exe I have the command line IMGTOOL.exe but I thought I remember using a Windows based tool a few years ago.


      • Robert Gault

        You can probably mount that 700k disk in MESS or VCC (which will only read the first 157k) and back it up to a normal sized disk.

        You can also use a PC raw file editor and cut off the extra bytes in the large disk image.

  • Another option you can try if you have Windows
    (1) Download the lhz file
    (2) Use WinRAR to extract the 3 files in the archive (Shang3.dat, Shanghai12.doc, Shanghai.b09)
    (3) Use MESS or VCC to create a blank OS9 virtual diskette
    (4) Use MESS wimgtool.exe to drag & drop the files onto the vitrual diskette
    (5) Transfer the files via Drivewire or CoCoNet

    • Thanks Ed. Your reply went to the wrong topic!

      I had forgotten about MESS and the image tool program. I hardly ever use emulators!

      Thats what I’ll do use MESS to make a .os9 image with the files in it and then write the image to disk with dskini.

      How do I run the .b09 program? Do i need to load anything? Do I need to find my original OS9 disks with basic09 on them?

      Thanks again.

    • Hi again Ed. I downloaded MESS but there is no winimgtool.exe where can I grab that?

  • sc

    yeah not much luck here. Even though all the math works out at 32 characters per line, 192 lines, 12 lines per “row” of text = 16 rows, it doesn’t turn out that way. Doesn’t seem to make a difference which 32 byte HRES bits I choose (000 or 010), nor whether I enable/disable attributes. Awww well, just thought it would be neat to see what you take as the low res 32×16 text display, but then be able to put lower case and all attributes on it…