CPC6128 !

[TFM]

That is exactly why I have kept 3 inch drives in all my 6128s. 3.5 inch drives always leave a gap in the case...

Aside of beauty  I like 3" discs for their reliability. Dunno what other people do, but the first pack of 10 Panasonic 3" discs I bought at beginning of 1987 are still working. Files I saved 1987 can still be read and there is not a single read error. 

[CraigsBar]

Aside of beauty  I like 3" discs for their reliability. Dunno what other people do, but the first pack of 10 Panasonic 3" discs I bought at beginning of 1987 are still working. Files I saved 1987 can still be read and there is not a single read error. 

Ditto. I think that 5mm thick black plastic case makes them bomb proof. So much more so than the 3.5 inch variety


I have never seen a 3 inch disc with a broken shutter.


the drives seem pretty reliable too so I have no complaints




(Although I did need to re-image my Gauntlet disc the other day when testing on the plus... due to the High Score writing bug that trashes the disc Oh well I just wrote the 'original dump' DSK from cpc-power back onto the original disc, and then flicked the write protect tab) all good, and the nasty bug will not trash my disc again


craig

[TFM]

Remember when I fucked screwed up my Gauntlet with old and awesome high score list when playing on a Plus the first time.    Still a nightmare! 


The bug is that the floppy head get's moved to quick after writing. That can not happen with regular 3" drives, but only with Plus drives which allow to move the head while writing the gap (after the sector). So in 1/4 of all cases the track register of the FDC is off, an this causes the troubles. I learnt about this when I made FutureOS compatible the the Plus. That bug did cost me 3(!) weeks of constant work, because it can not be reproduced reliable. The perfect thing to drive somebody nuts. ... Oh old memories, often enough I thought about to throw something out of the window. 

[arnoldemu]

The bug is that the floppy head get's moved to quick after writing. That can not happen with regular 3" drives, but only with Plus drives which allow to move the head while writing the gap (after the sector). So in 1/4 of all cases the track register of the FDC is off, an this causes the troubles. I learnt about this when I made FutureOS compatible the the Plus. That bug did cost me 3(!) weeks of constant work, because it can not be reproduced reliable. The perfect thing to drive somebody nuts. ... Oh old memories, often enough I thought about to throw something out of the window. 

@TFM: I am a bit confused how this is happening.

Is it this:

- seek to track
- write

and the seek has not finished fully and it can step extra?

or

- seek to track
- write
- seek for next

and the last seek happens too early?


if the track register of the FDC is incorrect, is the writing then failing? I think the sector id would not be found and the write would fail without corruption?

Or are you talking that the fdc writes the sector and starts to write the gap, at this point if a seek happened somehow, the fdc would then write on the next track and cause an error?

it does seem like there is some kind of problem with the seek step pulse and the plus drive.

How did you resolve it?

Do you have a delay to avoid this problem?

I am curious.

[TFM]

Ok, situation with 12 Volt 3" drives (CPC old generation):

- Write Sector, transfer all data bytes
- Start Seek command
- FDC waits until GAP is written (after data)
- Head starts moving, eventually arriving at new destination track


Situation for 5 Volt only 3" drives (6128 Plus):

- Write Sector, transfer all data bytes
- Start Seek command
- FDC writes GAP 70%-80% of time, but sometimes it tries to start to move the head, in this case:
  - Head remains on track to finish GAP writing, and..
  - Internal Track register of the FDC gets increased / decreased by one
- After GAP is written: Head starts moving, eventually arriving at new destination track

Result the Head is on a wrong track!


How to omit this?
- Read an Sector ID after writing the last sector of a track (this is how FutureOS does it)

When will it happen? / Not happen
- Happens with quick FDC routines
- Doesn't happen with slow FDC routines (most of all stuff)

[squale]

Ditto. I think that 5mm thick black plastic case makes them bomb proof. So much more so than the 3.5 inch variety


I have never seen a 3 inch disc with a broken shutter.


the drives seem pretty reliable too so I have no complaints




(Although I did need to re-image my Gauntlet disc the other day when testing on the plus... due to the High Score writing bug that trashes the disc Oh well I just wrote the 'original dump' DSK from cpc-power back onto the original disc, and then flicked the write protect tab) all good, and the nasty bug will not trash my disc again


craig

At the end, 3" is the solution but we can not find any these days !!! 

[Bryce]

Very good job, btw where is the HxC LCD screen ?

The owner didn't want a screen, he installed the HxC Software browser on the MegaFlash (which I also installed inside). The buttons are on the side, out of sight.

Bryce.