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Kaypro II won't boot dsk files #76225 01/17/12 10:27 AM
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Barry Nelson Offline OP
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The CPM disk files that used to boot on the Kaypro II now just result in the system sitting at an insert disk prompt...

Re: Kaypro II won't boot dsk files [Re: Barry Nelson] #76229 01/17/12 11:36 AM
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Robbbert Offline
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Been like that for months, since "someone" modified the disk controller...

Re: Kaypro II won't boot dsk files [Re: Barry Nelson] #76234 01/17/12 01:32 PM
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Curt Coder Offline
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It misses the first data byte:

'maincpu' (FF23): wd17xx_command_w $80 READ_SEC (cmd=C0, trk=00, sec=00, dat=00)
wd179x: Read Sector callback.
sector found! C:$00 H:$00 R:$00 N:$02
wd17xx_data_callback: $18 (data_count 512)
wd17xx_data_callback: $FE (data_count 511)
'maincpu' (FF29): wd17xx_data_r: fe

Re: Kaypro II won't boot dsk files [Re: Barry Nelson] #76235 01/17/12 02:29 PM
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For the ti99 systems, the standard TI disk controller and the BwG controller, both using the wd17xx controller, seem to work correctly (just tested).

Michael
(didn't touch the controller for a long time, so it wasn't me)

Re: Kaypro II won't boot dsk files [Re: Barry Nelson] #76236 01/17/12 03:32 PM
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Barry Nelson Offline OP
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Interesting. If I am reading what Curt wrote correctly, those are 512 byte sectors that the Kaypro is trying to read and it only got 511 bytes for one of them. I am not as familiar with the Kaypro system at the lower levels as I am with some other systems, but I am pretty sure although the TI may use a 17xx disk controller, it uses 256 bytes sectors. The other system that I am familiar with is the TRS80 Color Computer. It uses a 1773 (or 1793) disk controller, and is currently working ok, but also uses 256 byte sectors. So...

Maybe the problem only shows up when you have a 17xx disk controller using a 512 byte/sector format and not a 256 byte/sector format?

Re: Kaypro II won't boot dsk files [Re: Barry Nelson] #76241 01/17/12 03:50 PM
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R. Belmont Offline
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Looks more like a timing issue. The trace Curt shows indicates that the 17xx finds all 512 bytes fine but the Z80 doesn't bother with the first one off the disk.

Re: Kaypro II won't boot dsk files [Re: Barry Nelson] #76244 01/17/12 05:06 PM
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Curt Coder Offline
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Yes, it's a timing issue. The INTRQ/DRQ callbacks in the driver have a 25 Ás delay on them, and that is too long. I set it to 10 and the data gets loaded but after that the Kaypro just sits in HALT waiting for something to happen... wonder what is missing?

Maybe using OG's new WD1772.c would solve this and other timing issues in old computers?

Last edited by Curt Coder; 01/17/12 06:27 PM.
Re: Kaypro II won't boot dsk files [Re: Barry Nelson] #76251 01/17/12 06:42 PM
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Barry Nelson Offline OP
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Perhaps these changes are related then...
It is possible that variations in the computer design might be effecting how the WD17xx chips respond in different systems. The TRS80 Color Computer is also sensitive to the delay. The timing and pulse shapes that the wd17xx chips receives might be causing it to respond with different delays in the different actual systems. Perhaps calling wd17xx_set_complete_command_delay from the respective systems is not such a bad idea... At least that way we can fine tune one system without breaking 15 others... eek

Code:
2009-June-21 Robbbert:
- The Bugfix above, while valid, caused the Osborne1 to fail. This
  is because the delay must not exceed 14usec (found by extensive testing).
- The minimum delay is 1usec, need by z80netf while formatting a disk.
- http://www.bannister.org/forums/ubbthreads.php?ubb=showflat&Number=50889#Post50889
  explains the problems, testing done, and the test procedure for the z80netf.
- Thus, the delay is set to 10usec, and all the disks I have (not many)
  seem to work.
- Note to anyone who wants to change something: Make sure that the
  Osborne1 boots up! It is extremely sensitive to timing!
- For testing only: The osborne1 rom can be patched to make it much
  more stable, by changing the byte at 0x0da7 from 0x28 to 0x18.

2010-Jan-31 Phill Harvey-Smith
- The above bugfixes for the Kaypro/Osborne1 have borked the booting on the Dragon
  Alpha. The Alpha it seems needs a delay of ay least 17us or the NMI generated by
  INTRQ happens too early and doen't break out of the read/write bytes loops.

  I have made the delay settable by calling wd17xx_set_complete_command_delay, and
  let it default to 12us, as required above, so that the Dragon Alpha works again.
  This hopefully should not break the other machines.

  This should probably be considdered a minor hack but it does seem to work

2011-Apr-01 Curt Coder
- Set complete command delay to 16 usec (DD) / 32 usec (SD) and removed
  the external delay setting hack.

Re: Kaypro II won't boot dsk files [Re: Barry Nelson] #76252 01/17/12 06:45 PM
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R. Belmont Offline
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I agree with Curt, we need to get all the systems converted over to OG's new controller.

Re: Kaypro II won't boot dsk files [Re: R. Belmont] #76260 01/17/12 07:45 PM
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Barry Nelson Offline OP
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Originally Posted By R. Belmont
I agree with Curt, we need to get all the systems converted over to OG's new controller.

Is there is howto or a guide some where that describes how to change a system over to the new controller? How is the API for the new controller different from the older one?


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