12

These are headerless sector dumps of the 360KiB disks, and can be written directly to the appropriate floppies. Since you’re using Windows 98, I suspect the best tool to do is ImageDisk. You’ll need to convert the images first: BIN2IMD ATDOS331.360 ATDOS331.IMD DM=5 N=40 SS=512 SM=1-9 /2 (250kbps MFM, 40 cylinders, 512 bytes per sector, sectors mapped ...


12

These are disk- and tape images files for the Commodore 64 and computers using the same floppy drives and disk formats, like the VIC-20, or the Commodore 128. D64 are single-sided 5.25" disk images ("1541 images" for the Commodore 64), sometimes also called D41. D71 are double-sided 5.25" disk images ("1571 images") D81 are double-sided 3.5" disk images ...


10

You can't tell if a .do/.po disk image file is in DOS order or ProDOS order unless you recognize something on the disk. If it has a DOS 3.3 or ProDOS filesystem, it's pretty easy. Otherwise... not so easy. If you want to see how CiderPress does it, take a look at the AnalyzeImageFile function here. After peeling off .gz/.zip, it checks the file extension....


10

I support DMK in my MSX emulator, and bear in mind that it's a bit of a confused file format. It has a bunch of design deficiencies, and was clearly tightly coupled to the program that originally implemented it. But starting with the perfectly sensible stuff: The first 16 bytes are the header, which you seem to be familiar with — write protection, geometry, ...


8

A partly speculative answer, working backwards from the source code of Marat Fayzulin's ColEm, it appears to be a fixed-size sector dump. On line 52 of EMULib/FDIDisk.c you can see confirmation of the geometry you already know about: single sided; 40 tracks; 8 sectors per track; 512-byte sectors. Line 406 lists FMT_ADMDSK (i.e. Adam disk) amongst those ...


6

Since I've been writing code to interact with various systems' disk image formats over the past few weeks I'd like to add a little more information that's not in the current answers. Disk images and tape images are usually of a few different types and subtypes. I'm using my own terminology here so forgive me if there is standard terminology I'm not yet aware ...


5

I played around a bit with it, and it seems the solution is to basically emulate the full UART behaviour, in particular in regards to detecting start bits. Instead of framing statically by 10 bits, we need to walk the bits until we find a high -> low transition (the start bit), and then we take the next 9 bits as the 8 data bits (lsb first) and a high ...


5

DOS-ordered images were created by DOS programs that started reading from track 0 sector 0, continued to sector 15, moved to track 1 sector 0, and so on until the end of the disk. They are in DOS logical order: the first 256 bytes are T0S0, the next are T0S1, and so on. ProDOS-ordered images are created by ProDOS programs that started reading from block 0, ...


4

Look carefully at the docs again (Web Archive one). "The file bodies are stored after the directory entries. Basic program and data array files have an addition at the end of the file." If it is basic program, there are 4 bytes: 2 fixed values 127,170 and autostart line number 0.. 9999. If it is data array, there are also 4 bytes: 2 fixed values 127,170, 1 ...


4

From my answer to How do I know where the file directory is stored on a Spectrum +3 disk layout? Part 26 of the +3 manual is what you need to read. There is even a complete example of how to write boot code and how to store it into the disk. This part is the relevant one regarding which values the disk specification block must have: bootstart: ; ;The ...


4

Emulators should emulate the Disk ][ hardware at a low level, or they're going to have a bad time. Attempting to pull in the right set of sectors will work for standard DOS or ProDOS disks, but won't work for anything custom. You can find a commented disassembly of the boot ROM here and a "typical" T0/S0 here. You'll note there's a sector ...


3

USB floppy drives only support a limited set of disk formats: 720KiB (on DD floppies only), 1440KiB (“standard” HD), and in some cases, 1232KiB (“mode 3”, the format used on X68000 systems) and 1200KiB (so that 5.25” HD images can be written). If your images are 1440KiB images, then all that’s needed is to extract the raw sector image, and write it using cp ...


3

You can look at the file systems: Here are descriptions of the DOS file system and the ProDOS file system. They are quite different, so you attempt to list the files on the disk, usually one approach will produce garbage, and one won't. That's pretty obvious to a human, but less obvious to a program. Also keep in mind that there are .dsk images (in ...


3

I think some of the answers here are combining determining the disk format with detecting if it's bootable. I've answered how the format is detected on its own question, so here I'll concentrate on the boot process. The +3 tries to boot from a disc by using the DOS_BOOT function. This selects drive A:, closes any open files on it, and then tries to read ...


2

The Disk Masher System entry on the Archive Team wiki suggests the following tools: xDMS (Public Domain, portable C source) dms111 (Original Amiga software) Ancient Format Decompressor (decompresses to ADF) The linked xDMS page claims... Supports decompression of files compressed using all known DMS compression modes, including old and obsolete ones,...


2

It's probably best to take a look at the +3DOS DD_LOGIN function, since that's the ultimate source for how a +3 identifies a disc. What this does is: Call DD_SEL_FORMAT with A=0 to select the standard +3 format (180k, single sided, with one system track). Call DD_READ_ID with D=0 to read the identity of a sector (any sector) on track 0 of the disc. Look at ...


2

+3 disks are actually CP/M disks. Disk organization details are stored in the XDPB table, which is generated by the firmware from the data found at the beginning of the disk. This can be read on part 27 of the +3 manual: The PCW range disk format (used by the +3) is, in fact, a family of formats the precise member of which is defined in the 'disk ...


2

On a CPC system, you can determine if the disc is in System format (i.e. bootable) by the number of the first physical sector. If the sector is 41h, the disc is in System format, with 2 reserved boot sectors, whereas C1h means Data format, no reserved sectors. The PCW and Spectrum +3 can also determine the bootability of a disc from a 16-byte record on ...


2

Those are raw disk images. No special software is needed. You can use the DEBUG program - a part of DOS - to load the image from file to memory, and then to write it out to disk. I do suggest you try it out using either actual MS-DOS or FREEDOS, or by rebooting into DOS mode from Windows. Within debug, it’d go something like: N atdos331.360 - set the file to ...


2

In general, identifying a file format by the file extension can be misleading. Many files carry an extension that does not correspond to the actual format of their contents (just for one example, many DOS executables with the extension .COM are actually in the MZ format), while some formats have no single standard extension at all. Raw disk images in ...


1

In case of uncompressed images, you can extract them (without having to use an actual diskette) using Aaru (ex-DiscImageChef). AFAIK there is no modern tool which handles compressed images (staring with AA 5A), but there exist DIUNPACK.EXE for OS/2 which supposedly handles them (available on SAC.SK). DIUNPACK Release 3.03 01-30-96 Copyright (C) IBM ...


1

This answer is still a work in progress... A Unix emulator named "Apple //e Emulator" by Randy Frank (aka "apple2e" or just "ap2e" in filenames) goes right back to 1990. It used ProDOS order for both ProDOS and DOS 3.3 disk images! DOS 3.3: Note: the UNIX files contain all the data on a DOS 3.3 5.25 disk. However, the files ...


1

They are image files that contain the data from cassette tapes (T) and floppy disks (D).


1

It seems there is. There is an open source C library by John Elliot for working with a selection of disks and disk image formats called LibDsk, active as of August 2019. Among the supported formats it includes .DSK files, as used in CPCEMU, JOYCE and other Sinclair/Amstrad emulators. The JOYCE emulator mentioned is by the same author. The author added ...


1

But since this [boot] block is optional, there must be a way for the system to detect whether it's present or not. There isn't. The +3 (like the Amstrad CPC) doesn't autoboot. Using the Loader on a +3 (or |CPM on an Amstrad CPC) on a disk that's in Data or Vendor format (that is, does not have CP/M or custom boot code in the reserved tracks already ...


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