The Sinclair QL Forum

Errata :
Concerning the previous post, the Ql was only running with the SGC, without SMSQ/E being loaded.
Steve.

It unfortunately sounds as though the write head has faield on your disk drive - you may need to replace the disk drive unfortunately - although you could have a go with a good old fashioned head cleaner.

It can also be the disk controller chip on the Gold Card as they do sometimes fail - try writing to another disk drive if you have one...

I have some bare ED disk drives here if you need one of those.

Hi Rich,
I can write to floppies on both systems and read them. It is just that what is written on one system can't be read on the other, altough not in all cases!

stevepoole wrote:Hi Rich,
I can write to floppies on both systems and read them. It is just that what is written on one system can't be read on the other, altough not in all cases!

Is this using the same disk drive, or different disk drives?
If using different drives, it maybe that the heads are out of alignment on one of the drives (and no it is not easy to set up the alignment yourself).

Mark

Hi Mark,
This is using two different disk drives. But the strange thing is that some floppies will read on either or both drives, but not all... All floppies are HD, and the problem is the same whether formatted QDOS or MSDOS!
Thanks.
Steve.

Steve's problem is very well known to me. It happens to me all the time when disks have been written to on the QL system before taking to the PC. Any attempt to read them in QPC basically seems to destroy the disk, as though writing to them on QL was incomplete, or the QL was reading from slave blocks and the disk was never really "good" in the first place (i.e. was not recognising the disk was bad).

Not the drives, since exactly the same thing happens with both sets of dual drives and the other single drive.

Gave up trying to get an explanation for this a long time ago as nobody seemed able to explain what might be happening. Sadly, I get asked about this from time to time via Quanta helpline - it seems to be happening to several users.

If you are using HD disks - are you using them formatted as HD disks (and do they report as 2880/2880 sectors) or are you trying to format them as DD disks - that is a recipe for disaster.

Also it can depend on how you are reading the disk in QPC - I have great problems reading formatted QL disks with QPC and a USB external disk drive. However, q-emulator seems to cope with them better.

Every now and then, neither QPC nor q-emulator will read a QL formatted DD disk. This is due to the lack of proper disk controllers and even DD support in Windows 7/8 etc and can be exhibited in several ways:

a) If it is a re-formatted HD disk, the PC drive will try to recognise it as a HD disk and so the driver seems to get confused
b) If it has not been formatted to the full 1440/1440 (or 2880/2880 for HD) sectors, sometimes I can see the directory, sometimes I can't see anything, and sometimes I can see the directory but not read files off it.
c) Sometimes even a properly formatted QL DD disk is not recognised at all and doesn't even fire up the USB disk drive in an attempt to read whatever has been inserted.

Some of these problems can be overcome if I format a DD disk from DOS before trying the QL DD disk using FORMAT a: /t:80 /n:9

Then suddenly all the problems with trying to read the QL formatted DD disk disappear.

Drat, was replying to RWAP when Internet Exploder decided to explode, and I lost my long reply.

On my PC, DD disks cannot be formatted at all in neither DOS nor QDOS formats, from DOS, Windows or a QL emulator. Even with the FORMAT command explicitly setting type.

I have great difficulty formatting HD QL disks (HD DOS/Windows formatting works), both emulators struggle (QPC has better success rate with HD disks than QemuLator for unknown reasons) - It is easier for me to format several HD disks on a QL and choose the 50% or so which work on the dratted USB floppy drive on my PC. Sadly, my PC has neither a floppy drive bay nor motherboard connection for floppies, so USB is the only option, I can't try out a traditional internal floppy drive to compare.

I'm forced to the conclusion that USB floppy drives are a PITA when it comes to QL disks.

dilwyn wrote: I'm forced to the conclusion that USB floppy drives are a PITA when it comes to QL disks.

Well it turned out from out HxC experiments that there is no difference between QL/PC HD & DD disks.

The physical format is the same, only the file system changes.

MSDOS and MS Windows are a bit touchy when it comes to disks formatted on other systems. Atari ST users have found out that although the file system is the same, some of the information in the disk catalog / boot sector (I forget the details) has to be what MSDOS / MS Windows is expecting. Otherwise sometimes it causes problems.

USB floppy drives are even more picky than shugart / PC internal drives, because the circuitry is only designed for use with MSDOS / MS Windows disk formats. Some will not even write DD disks

Not sure if any of the above helps

Mark