More Tetroid SGC issues: Floppy

[stephen_usher]

I've been recently having issues with the Tetroid SGC clone corrupting floppy images on the Gotek and failing to format.

I think this started after I had to replace the clock battery.

Formatting fails because for some reason the SGC is trying to write beyond track 82, which doesn't exist. I'm wondering if this is what's also corrupting the other images upon write.

Unfortunately I can't find a full copy of the Miracle systems manuals (the text scans on-line seem to be partial scans of a complete manual as the SGC one is only a few K, as if the GC one and none of them are exactly reference manuals).

Are there NVRAM settings to tell the SGC to just use a normal format and not try to be clever?

[stephen_usher]

Maybe it's that retched flp_jiggle again.

[ones' complement]

Yep, another bit stored in RTC chip

• FLP JIGGLE
  
  The Gold Card and Super Gold Card incorporate a software fix for a
  problem when accessing Mitsubishi ED disk drives in the form of a
  number of rapid steps of the drive head. This rapid stepping of the
  drive head, referred to as a jiggle, when applied to other makes and
  types of disk drive can result in the drive giving "not found" or 'bad
  or changed medium' errors. There is a command to enable or disable this
  jiggle.
  
  Suppose your system comprises one of our Dual ED Disk Drives for FLP1_
  and FLP2_ and some other make of double drive for FLP3_ and FLP4_. To
  boot up reliably the head jiggle must be enabled so from the command
  line enter: FLP_JIGGLE 1
  
  FLP3_ and FLP4_ do not require the head jiggle so add the following
  lines to the start of your boot program:
  
  FLP_JIGGLE 3,0
  FLP_JIGGLE 4,0
  
  If the command is given only one parameter it is memorised and remains
  in force the next time the QL is powered up or reset. Individual
  settings are not memorised and have to be set each time the QL is
  powered up or reset.

Perhaps a FLP_JIGGLE 0 might solve problem.

[dilwyn]

I've been recently having issues with the Tetroid SGC clone corrupting floppy images on the Gotek and failing to format.

I think this started after I had to replace the clock battery.

Formatting fails because for some reason the SGC is trying to write beyond track 82, which doesn't exist. I'm wondering if this is what's also corrupting the other images upon write.

Unfortunately I can't find a full copy of the Miracle systems manuals (the text scans on-line seem to be partial scans of a complete manual as the SGC one is only a few K, as if the GC one and none of them are exactly reference manuals).

Are there NVRAM settings to tell the SGC to just use a normal format and not try to be clever?

As far as I know, the later Miracle manuals were supplements to earlier manuals, so you were never fully sure if something in an earlier manual (e.g. Gold Card) also applied to the Super Gold Card.

Some commands to consider may be FLP_TRACK no_of_tracks and FLP_START startup_time (in 1/50 second units, default IIRC is .6 second). AFAIK the FLP_JIGGLE was only needed when FLP1_/FLP2_ were Mitsubishi ED drives. There is also FLP_SEC security_level ( to set security level from 0 to 2, default 2, the most secure against disc changes etc).

Might be worth trying to explicitly issue an FLP_TRACK 80 before a format to see if that has any effect.

[Dave]

o/` My floppy don't jiggle jiggle
o/` It thunks
o/' My data don't wiggle wiggle
o/' It 'bad or changed medium'

[stephen_usher]

It turns out that it actually requires "flp_jiggle 1" to work with both the Gotek and the DD drive underneath it in the unit otherwise writes are unreliable.

I had to do flp_track 80 explicitly too, though changing the flp_jiggle made a difference too. Without jiggle the SGC tries to seek to track 87! With jiggle it only tries track 83.