Qume or Shugart - CP/M

This is a discussion on Qume or Shugart - CP/M ; I have both drives and there is a big difference in usable space.. I was wondering which is the better drive to use on a daily bases. I like the Qume dt/8 with dual heads but the z80 4mhz may ...

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Thread: Qume or Shugart

  1. Qume or Shugart

    I have both drives and there is a big difference in usable space.. I was
    wondering which is the better drive to use on a daily bases. I like the Qume
    dt/8 with dual heads but the z80 4mhz may be under powered. The Shugart 800-2
    with double density seem to work better with the z80. I have a 8086 but would
    need to make a few small changes on the bios on the disk controller to see if it
    would be a better CPU card. Thanks again

  2. Re: Qume or Shugart

    On Feb 2, 8:28 am, Keith wrote:
    > I have both drives and there is a big difference in usable space.. I was
    > wondering which is the better drive to use on a daily bases. I like the Qume
    > dt/8 with dual heads but the z80 4mhz may be under powered. The Shugart 800-2
    > with double density seem to work better with the z80. I have a 8086 but would
    > need to make a few small changes on the bios on the disk controller to see if it
    > would be a better CPU card. Thanks again


    Hi Keith,

    Not sure what yuu mean when you say the Z80 is "under powered". What
    problem are you having? I am running double sided Qume's, Shugart
    860's, and Shugart 850's with no problem using the same controller. It
    sounds like you may have a controller or drive set up problem, not a
    CPU problem. There are a couple mods to the CCS controller board that
    help with noise and timing issues that are not documented by CCS. Do
    you know if your board has those mods (some cuts and jumps not
    normally on the board)?


  3. Re: Qume or Shugart

    On Fri, 02 Feb 2007 11:28:23 -0500, Keith
    wrote:

    >I have both drives and there is a big difference in usable space.. I was
    >wondering which is the better drive to use on a daily bases. I like the Qume
    >dt/8 with dual heads but the z80 4mhz may be under powered. The Shugart 800-2
    >with double density seem to work better with the z80. I have a 8086 but would
    >need to make a few small changes on the bios on the disk controller to see if it
    >would be a better CPU card. Thanks again



    Sounds like your CPU is fast enough but the timing for drive ready or
    step rate is causing problems and that is not a CPU speed issue. A
    4mhz Z80 will do DD regardless of the drive used.

    For example if te step rate is too fast for the drive it's possible to
    have the head land at the wrong track and you get a read error (or
    hang). If the head load wait is too short the head can be or the load
    mechanism can be still in motion and result in problems. Those
    were some of the subtle problems going from one drive to another
    especially with 8" and some of the 5.25" drives. To give and idea
    of the problem some of the 5.25" drives needed 40mS step rate
    (SA400 series) and some of the CDC 8" drives were 3mS track to track
    step rate. I forget if the Qumes were faster than the Shugarts (6ms)
    or slower.

    I posted earlier that I use a pair of SA860s with a CCS2200 (CCS CPU,
    64kram, disk controller, serial IO and all in their s100 box) and it's
    solid running DD though I've since set it up with 3.5" floppies
    running as if they were 80 track two sided 5.25 (same format, 780k)
    as they make less acoustic noise.

    Going to an 8086 is a huge leap as it's not software compatable with
    any of the CCS firmware or software. Again it's still a CPU speed
    issue and the 8086 would have to run at something faster than 4mhz to
    work with the CCS FDC. The most common system that allowed for other
    than 8080/z80 was the Compupro as they had boot proms that were
    jumperable for z80 or 8088-8086.


    Allison


  4. Re: Qume or Shugart


    >Hi Keith,
    >
    >Not sure what yuu mean when you say the Z80 is "under powered". What
    >problem are you having? I am running double sided Qume's, Shugart
    >860's, and Shugart 850's with no problem using the same controller. It
    >sounds like you may have a controller or drive set up problem, not a
    >CPU problem. There are a couple mods to the CCS controller board that
    >help with noise and timing issues that are not documented by CCS. Do
    >you know if your board has those mods (some cuts and jumps not
    >normally on the board)?


    The CCS board is a Rev B board that does not have any cuts or mods. I do have
    what maybe a noise problem sometime so if you have any info on what the rev B
    boards needs I would apprecate it.
    I maybe going down the wrong path as I assumed from some discussions that the
    z80 speed maybe a problem with high density drives. I forgot that CCS code is
    written for a Z80.

    I can try some changes on step and head settling time if possible.

  5. Re: Qume or Shugart

    On Feb 2, 11:58 am, Keith wrote:
    > >Hi Keith,

    >
    > >Not sure what yuu mean when you say the Z80 is "under powered". What
    > >problem are you having? I am running double sided Qume's, Shugart
    > >860's, and Shugart 850's with no problem using the same controller. It
    > >sounds like you may have a controller or drive set up problem, not a
    > >CPU problem. There are a couple mods to the CCS controller board that
    > >help with noise and timing issues that are not documented by CCS. Do
    > >you know if your board has those mods (some cuts and jumps not
    > >normally on the board)?

    >
    > The CCS board is a Rev B board that does not have any cuts or mods. I do have
    > what maybe a noise problem sometime so if you have any info on what the rev B
    > boards needs I would apprecate it.
    > I maybe going down the wrong path as I assumed from some discussions that the
    > z80 speed maybe a problem with high density drives. I forgot that CCS code is
    > written for a Z80.
    >
    > I can try some changes on step and head settling time if possible.


    I will try and find the info soon for the two mods. FYI, the CCS BIOS
    is wriiten in 8080 code. Only the Firmware and CCBOOT portions are Z80
    code.

    You can try playing with the headload and seek time, but if you have
    not modified the original code form CCS it was already pretty generous
    and I do not know if that's the problem. In fact I changed the seek
    time to 3ms for the Shugart 850's and 860's, and they run with no
    problem. There is no headload for the 860's (normal config is have the
    DC motor come on when selected). The Qume's I have also run fine with
    the standard settings in the CCS code.

    Also, as a comment to the Compupro sytems. I have systems running with
    the 8085/8088 and the Macrotech Z80/80286. These are geat machines for
    running CP/M 2.2, CP/M 86, and Concurrent CP/M all on the same
    hardware without changing jumpers, etc. Just a matter of what boot
    disk you put in. I also have put Seagate ST225 hard disks on them and
    they work great! Good systems for assembling and compiling.

    Rich



  6. Re: Qume or Shugart

    > > The CCS board is a Rev B board that does not have any cuts or mods. I do have
    > > what maybe a noise problem sometime so if you have any info on what the rev B
    > > boards needs I would apprecate it.
    > > I maybe going down the wrong path as I assumed from some discussions that the
    > > z80 speed maybe a problem with high density drives. I forgot that CCS code is
    > > written for a Z80.

    >
    > > I can try some changes on step and head settling time if possible.


    Keith,

    Looks like I was able to duplicate the problem on one of my Qume
    drives. It only happens once in awhile but as you atated 99% of the
    time you do not get the "DRIVE "A" NOT READY" error. Looking at the
    BIOS changingthe hedlod time or the seek time will not fix this. The
    problem is in the following part of the CCS BIOS;

    EOJ1: IN DSTAT ;GET THE DISK STATUS
    STA STATUS
    ANI 0FCH
    IF MAXI
    RP ;DONE IF DRIVE IS READY

    Simply put the headload delay routine and the disk retry routine is
    done after the drive is selected and a seek, read or write operation
    is peformed. However in the BIOS when using an 8" drive it first
    checks the READY status when re-selecting the drive. Unfortunately it
    is a very short dealy in checking for "READY" which some drives may
    not meet all the time, as with the QUME's. This routine shoud really
    be re-written to at least do one or two retry's, or have a delay
    BEFORE going to the error message. I do have an easy fix that should
    work fine if you elect to try it, and should be easy to check out. Of
    course you can also rewrite the routine, and re-assemble, to do this
    better at some point, which I may do later.

    First to see if this fixes your problem run DDT and then subsitute
    location F5C9 (this assumes a 64k system load). Using the "S" command
    do the following;

    -SF5C9

    -F5C9 F0
    -F5CA 3A -"Ctrl C"

    A>

    This has he changed the instruction "RP" a conditional return, to
    "RET" and unconditional return. Do NOT do a cold boot, and try running
    your copy routines etc. You should not see anymore DRIVE NOT READY
    errors. This should cause no other problems and will treat the 8"
    drives like the 5 1/4" drives as far as drive re-selecting goes. If
    for some reason you access a drive that has the door open, or is not
    READY for some reason you will get the BDOS error and as soon as you
    put a disk in, or close the door it will read the disk just fine. So,
    there should be no functional or operational problems. If this works
    for you then you must change it in RLOCBIOS.COM by running "DDT
    RLOCBIOS.COM" and changing the same byte which will now be at location
    0599. After exiting DDT type "SAVE 10 RLOCBIOS.COM" and you are set.

    Rich



  7. Re: Qume or Shugart


    >
    >This has he changed the instruction "RP" a conditional return, to
    >"RET" and unconditional return. Do NOT do a cold boot, and try running
    >your copy routines etc. You should not see anymore DRIVE NOT READY
    >errors. This should cause no other problems and will treat the 8"
    >drives like the 5 1/4" drives as far as drive re-selecting goes. If
    >for some reason you access a drive that has the door open, or is not
    >READY for some reason you will get the BDOS error and as soon as you
    >put a disk in, or close the door it will read the disk just fine. So,
    >there should be no functional or operational problems. If this works
    >for you then you must change it in RLOCBIOS.COM by running "DDT
    >RLOCBIOS.COM" and changing the same byte which will now be at location
    >0599. After exiting DDT type "SAVE 10 RLOCBIOS.COM" and you are set.
    >
    >Rich
    >



    That does seem to fix it. Thanks
    I noticed that you may keep the loading of rlocbios on your boot disk. I was
    able to get all the cccbios on the boot sectors but changing anything is a real
    pain now compared to keeping the rlocbios which is easier to compile and change
    or to use ddt. I may have to change that and enable the rlocbios loading at boot
    time. I assume that is what you do on you boot disks.
    How many drives do you have running on the ccs controller. I would like to add
    another one but I have had trouble finding the cable parts for the pcb edge
    connectors on the shugart/qume drives.

    Thanks again.

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