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  • RX02 with QBus at a 11/93 System - Booting "BOOTBLOCK ERROR"

    From Mikesch@mikeschpdp@gmail.com to alt.sys.pdp11 on Tue Feb 7 10:58:54 2023
    From Newsgroup: alt.sys.pdp11

    Hello,

    I run a RX02 drive system on a 11/93

    Floppies with RT11 V5.7 created on a 11/94 with RX02 drive.
    Floppies are bootable at he 11/94 system without errors.

    cleaned the drives and heads
    checked the belts
    checked the motors stepper and drive
    lubricant to the steppers spindle
    checked the power supply

    11/93 bootable from RL02
    can't the floppies
    booting from DY0 oder DY1 --- result bootblock error
    - but the floppies are OK (checked on another RX02 at a 11/94 and a DILOG floppy system (Shugart) at a 11/73)

    drive reset, step to track zero working, head load working - but the floppy is not readable

    checked with 2 another pairs of controller and read/write boards at the RX02 drive - same results

    any ideas what's the reason for the problem.
    How can I check mechanical adjustment of the drives

    I hope anybody knows more about this problem

    regards

    Michael
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  • From Johnny Billquist@bqt@softjar.se to alt.sys.pdp11 on Wed Feb 8 18:34:38 2023
    From Newsgroup: alt.sys.pdp11

    On 2023-02-07 19:58, Mikesch wrote:
    Hello,

    I run a RX02 drive system on a 11/93

    Floppies with RT11 V5.7 created on a 11/94 with RX02 drive.
    Floppies are bootable at he 11/94 system without errors.

    cleaned the drives and heads
    checked the belts
    checked the motors stepper and drive
    lubricant to the steppers spindle
    checked the power supply

    11/93 bootable from RL02
    can't the floppies
    booting from DY0 oder DY1 --- result bootblock error
    - but the floppies are OK (checked on another RX02 at a 11/94 and a DILOG floppy system (Shugart) at a 11/73)

    drive reset, step to track zero working, head load working - but the floppy is not readable

    checked with 2 another pairs of controller and read/write boards at the RX02 drive - same results

    any ideas what's the reason for the problem.
    How can I check mechanical adjustment of the drives

    I hope anybody knows more about this problem

    If the floppies are readable by one drive, I would try using that drive
    on the system you want to boot from. That should eliminate any problems
    with the drives themselves.

    Johnny
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  • From Mikesch@mikeschpdp@gmail.com to alt.sys.pdp11 on Thu Feb 9 02:42:33 2023
    From Newsgroup: alt.sys.pdp11

    Johnny Billquist schrieb am Mittwoch, 8. Februar 2023 um 18:34:41 UTC+1:
    On 2023-02-07 19:58, Mikesch wrote:
    Hello,

    I run a RX02 drive system on a 11/93

    Floppies with RT11 V5.7 created on a 11/94 with RX02 drive.
    Floppies are bootable at he 11/94 system without errors.

    cleaned the drives and heads
    checked the belts
    checked the motors stepper and drive
    lubricant to the steppers spindle
    checked the power supply

    11/93 bootable from RL02
    can't the floppies
    booting from DY0 oder DY1 --- result bootblock error
    - but the floppies are OK (checked on another RX02 at a 11/94 and a DILOG floppy system (Shugart) at a 11/73)

    drive reset, step to track zero working, head load working - but the floppy is not readable

    checked with 2 another pairs of controller and read/write boards at the RX02 drive - same results

    any ideas what's the reason for the problem.
    How can I check mechanical adjustment of the drives

    I hope anybody knows more about this problem
    If the floppies are readable by one drive, I would try using that drive
    on the system you want to boot from. That should eliminate any problems
    with the drives themselves.

    Johnny

    Hello Johnny

    Drives are all working - because checking them attached to the second RX02 system.


    Seems I've found a reason:

    With the QBus RX Controller the systems seems to be very critical with the cable lenght between Controller and RX02 unit.

    Tested with a modern 3 ft ( aprox. 1 m) cable and got read errors and bootblock error on booting.

    Yesterday used a original 15 ft (aprox. 4,6 m) DEC cable and now it works!

    Doing a cross check with the 3 ft cable with the unibus RX controller inside my 11/94 - and it works with original 15 ft and short 3 ft cable.

    This evening I'll try with a modern 15 ft cable - I've to press it first.

    There is a difference in cable problems one the the RX contr. at unibus and the RX contr. at QBus.

    I'll will post the test results - I have 4 QBus RX-Controller's - I'll check all and 3 Unibus RX-controllers - also check this.

    regards

    Michael
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