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1

I don't remember them having a “name”. Disk interchangeability was less of a thing than it became between 16-bit computers. Amstrads were very much not interchangeable, since they had the Hitachi 3" drives, used by Tatung (UK) and very few others. Even the PCW9512+ with its 720 K 3½" drive used a format derived from the earlier CPC disks. The format is CP/M*...


1

The Amstrad CPC manual (chapter 7 part 12) listed three "disk formats" supported by AMSDOS, which it named "System", "Data only" and "IBM" (CP/M 2.2 only). All three of these formats had: 40 tracks 64 directory entries 512 bytes per sector, no matter the track. And the format-specific characteristics: System had 9 sectors per track, two reserved tracks ...


5

OK, this is very dusty material in my memory, so I'm relying a bit on Google/Wikipedia here. I may be able to find some of my printed documentation, but it will take a while. The granule was the allocation unit for the filesystem. I don't remember the granule size on single-density drives, but Wikipedia says for double-density drives it was 6 sectors per ...


1

After Googling this for an hour or two and not finding much, I have found something solid just minutes after posting my question! From page 40 of TRS8BIT volume 09 issue 02 from June 2015 there is an article on a "FreHD Expansion Interface" which includes this paragraph: If a WDC1771 Disc Controller is found then the LII ROM programs the chip to ...


5

I think possibly your emulator is fooling you. Per this FUSE feature request, leading to this patch in particular and this commit, FUSE synthesises a boot.b and adds it to the disk directory if you open a disk that does not otherwise have one. So the reason that you can't locate the file within the disk image is that it isn't there. The emulator is ...


1

TR-DOS Files themselves have no header at all. Metadata is stored in the directory section of the disk, along with the filename. The metadata has a type field, which is also the file extension. Depending on this field you interpret some of the other fields in different ways. "B" for Basic programs. "C" for machine code, or any binary file really such as ...


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Some USB floppy drives don't support double-density floppy disks (as opposed to the newer high-density disks that are usually formatted to 1440KB). I think it's usually a limitation of the controller chip interfacing between USB and the drive itself. You should try using a different drive, and look specifically for reviews of its performance on double-...


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Since the question specifically references Commodore 8-bit drives, I thought I'd add a few details here. The PET/CBM series dual drives used both configurations internally: While the 5.25" drives (like the 4040 in the question) were stacked horizontally the 8280 stacked two 8" drives vertically: These units were, in turn, designed to be stacked ...


2

There is no 'end marker' for a CP/M directory in the same way that there is for MS-DOS. When searching the directory, you need to look at all entries. To get the size of the directory for a PCW / +3 disc, start with the number of directory blocks in the disc specification. Multiply that by block size and divide by 32 to get the number of directory entries. ...


0

Track/cylinder its single circle on the surface or set of circles on each surface/head forming cylinder (one spin). Each containing several sectors. How many is chosen by physical format of the media and limited by data density. Sector its predefined fixed size chunk of usable data. The size is chosen by physical format but is limited by used HW so you ...


2

It’s just nomenclature for 40-track (‘single’) versus 80-track (‘double’) drives. It’s not 3”-specific, e.g. here is a reference using the same terminology for 5.25” drives; 3” drives don’t do anything differently from 3.5” or 5.25” drives, and use regular Shugart signalling. The original PCWs, the CPC and the Spectrum all used 40-track drives; later PCWs ...


6

The 2.88MB "extended density" disks have a different type of coating on them, which normal "high density" drives are not optimised to read or write. So you might not reliably be able to format it even for 1.44MB. I believe these disks were never common and are now decidedly rare, as are the drives to work with them. A 1.44MB drive is also not designed to ...


3

If the drive is described as a 1.44MB drive, it's not going to be able to write a 2.88MB disk at 2.88MB. I think you can reformat a 2.88MB disk down to 1.44MB, but I think that's not what you're asking.


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