Questions tagged [file-format]

Relating to the encoding format of data within files.

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3 votes
0 answers
110 views

Can MAME save to cassette tape formats other than WAV? [closed]

MAME seems to be extremely unintuitive to use and extremely poorly documented. But it supports a ton of machines, some of which I haven't found other emulators for, so I've been persevering with it ...
4 votes
1 answer
160 views

Does the .sna snapshot file format for Sinclair ZX Spectrum emulators support a 16k variant

I'm playing with emulator and file format programming again. One of the common game snapshot formats for the Sinclair ZX Spectrum is the .sna format. I know it comes in a 48k format and a newer 128k ...
11 votes
2 answers
975 views

Why does the .z80 emulator-snapshot format have separate fields for the 8-bit refresh register and bit 7 of R?

I've been looking at the .z80 file format for Sinclair ZX Spectrum games. Most docs discussing the format include pretty much this wording: Offset Length Description -------------------------...
21 votes
2 answers
1k views

Where and when did the ".s" suffix for assembly-language source files originate?

The closest I was able to find on StackOverflow is What are .S files?, in which no answerer addresses why we use .s for assembly. (And .S for preprocessor/macro assembly; and gcc -S to produce ...
12 votes
1 answer
391 views

What are these compression types in the ARC file format?

The file format of the SEA ARC compression tool, also used by the PKWare PKARC tool, allowed the following compression types: Packing (RLE encoding) Squeezing (static Huffman coding) Crunching (LZW)...
10 votes
2 answers
1k views

What tape format did the Nintendo Famicom Data Recorder use?

I just learned from a YouTube video that in Japan there was an add-on for the original Nintendo Famicom console that included a keyboard (HVC-007) and compact cassette tape player & recorder (HVC-...
7 votes
1 answer
553 views

What's up with the ASxxx and the "CoCo Disk BASIC binary format"?

The ASxxxx assembler system is a multi-platform assembler that supports a lot of different CPUs, including Z80, 6800, 6502, 6809, etc. I'm intending to use it to build software for a variety of ...
8 votes
5 answers
2k views

Any tools (that actually work) for viewing PDF files in FreeDOS?

I recently installed FreeDOS on an old laptop and then transferred some dosbox based GOG games I own to the FreeDOS installation. The problem is the manuals for these games is in PDF format and I ...
10 votes
1 answer
239 views

Commodore / Apple II GEOS Document Cross-Platform Compatibility

As I have never used Graphic Environment Operating System (GEOS) on an Apple II (only I on a Commodore 64), I have always wondered were the documents created (from programs such as GeoWrite and ...
28 votes
2 answers
3k views

Did INI files work in a different way on Windows 3.x than today?

I am dealing with an application that still uses INI files for configuration. I wanted to make a temporary change to an INI file, but the result was not what I expected. Let's say the original INI ...
7 votes
1 answer
463 views

What is the TPG file format used in the PlayStation release of Zork I?

I'm looking at the Japanese releases of Infocom games, curious to understand how the engine works. Four games were released for the PC98, one of which added graphics for the rooms (Moonmist). Later, ...
20 votes
1 answer
3k views

How did large .COM files work?

An MS-DOS .com file is just raw code/data without header, thus no linking information, and was limited to be loaded into just one segment (64kB). That's the reason corrupted binaries would print "...
1 vote
2 answers
539 views

What is the easiest way to access/convert Lotus NSF files?

I would like to read some .NSF files (preferably on Linux). Converting to PDF is ideal, but anything else that uses modern formats (e.g. XML) is fine. When I google "nsf viewer" I get many ...
10 votes
0 answers
193 views

Which versions of StuffIt introduced backwards-incompatible changes to the file format?

In order to help people who want to integration-test tools which shell out to The Unarchiver's lsar and unar utilities, I'm trying to build a legally clean repository of test archives in StuffIt SIT ...
12 votes
6 answers
5k views

How can I tell whether a DOS-looking exe. requires a 32-bit CPU to run?

Is there some simple method for determining if a DOS (or OS/2, or Windows etc.) binary (.exe or .dll) is 16-bit or 32-bit? The Linux file command just says "executable". I want to ...
42 votes
5 answers
8k views

Why didn't C++ specify filename extensions?

Apparently even today there is no single "official" standard for C++ file extensions. There are just common conventions. To me this stands out as an anomaly... file extensions are heavily ...
6 votes
1 answer
269 views

Cross-Compatibility of UCSD p-Machine Versions?

I currently have Apple Pascal (and Fortran, and PILOT) running on an Apple IIgs emulator on Windows. As near as I can tell, it's UCSD p-System II.something. I also have a DOS-hosted UCSD p-System, IV....
7 votes
1 answer
143 views

Compucolor 2 emulator CCEmu's `.ccvf` disk format

This Compucolor 2 emulator uses disk images with the file extension .ccvf. Here is an example file. I would like to understand how to interpret that format. I understand from the documentation that ...
23 votes
2 answers
6k views

How to convert Amiga DMS to ADF?

Our demoscene group managed to release only one demo before it fell apart, but these being the early days of the Internet in my country, and me getting lucky with obtaining access to it and creating ...
5 votes
2 answers
702 views

How can I extract game data from Nitemare 3D files?

I am trying to reverse engineer an old Wolf3D style Dos game named "Nitemare 3D". I can get a raycasting engine with directional sprites running pretty easily using SDL2, but I have no experience with ...
3 votes
1 answer
278 views

What is the *BEAST* event-recording software grammar?

I recently recovered a data-set my father (a biology professor) recorded at UC Berkeley in the 90s on Stickleback mating behaviors. He says the data was recorded using the "open-source BEAST ...
10 votes
1 answer
592 views

Understanding the DMK disk image file format used by TRS-80 emulators

DMK is a low-level disk image file format used by TRS-80 Model I & Model III, Tandy Color Computer, Dragon 32 & 64, and MSX emulators. It's capable of representing copy-protected disks and all ...
63 votes
6 answers
15k views

Why did base64 win against uuencode?

From the the two methods of encoding 8-bit data as human-readable ASCII, for a time, uuencode format was more popular. USENET 'binaries' groups were filled with uuencoded posts with whatever goodies ...
4 votes
1 answer
399 views

What does it mean when "The Good Old Days" have several seemingly identical downloads for the same game?

This happens for numerous games. If I search, for example, for "Spear of Destiny", I get this: https://archive.org/details/TGODFloppyCollection?and%5B%5D=spear+of+destiny&sin= Four ...
4 votes
3 answers
392 views

What is this Intel Hexadecimal-like file format in this Tiny BASIC dump?

I am looking at this Tiny BASIC dump which seems to consist of two sections, the first being a list of symbol addresses, and the second one containing Intel Hexadecimal records with a leading space: ...
2 votes
0 answers
175 views

Has anyone heard of SCHEMA page layout tool?

I've found a text formatting tool, under the name of SCHEMA, which would accept an input language like *RED *0STA*NN*RG*1RL*0MCS1 20 *3/ *MDLorem ipsum dolor sit amet, *MDconsectetur adipiscing elit, *...
3 votes
0 answers
221 views

Do the Tandy CoCo and the Dragon 32 & 64 use all the same disk image file formats?

Tandy's TRS-80 Color Computer "CoCo" and the Dragon 32 & 64 were very similar but not clones and not the same. Floppy disk versions used totally different DOSes and disk layouts. Both ...
7 votes
1 answer
352 views

What floppy disk format and layout and what disk image format are used for the Coleco Adam?

I just found out that emulators for the Coleco Adam use a disk image file format with the DSK file extension. This is a very very overused extension on many different disk formats. Though a few DSK ...
1 vote
1 answer
157 views

Opening a .zbd file

I have a .zbd file from my military service with sensitive information on it from 2004. I have downloaded the ZoomBrowser from Canon, it does not recognize it as a file. I downloaded the Zebedee ...
3 votes
1 answer
169 views

What is the layout of the directory track on a TRS-80 Model I/Model III disk?

I've decided to add support for some more classic Z80 computers I used to use to my Ghidra modules, and the first Z80 systems I used were the TRS-80 model I and model III. I've found documentation ...
7 votes
2 answers
1k views

How can I programmatically determine whether an Apple II .dsk disk image is a DOS .do image or a ProDOS .po image?

I'm interested in working with the most common Apple II disk image file format, .dsk. (I only programmed these machines briefly in Basic around 1979-81 and have not been in the emulator scene, so I'm ...
3 votes
1 answer
270 views

Do TRS-80 Model I and Model III load and execute /CMD files using specific memory addresses?

/CMD files on the various TRS-80 Model I and III OSes are machine code command files. They seem to have some internal format but not really a file header. They often start with 01 02 and then a 16-...
7 votes
1 answer
414 views

What is the format of the static libraries shipping with legacy Microsoft C for DOS?

I have installed Microsoft C 5.10 on DOS 6.22. It created a 'LIB' directory with static libraries to link against. Now I need to extract the symbols and the code for the functions from them, but can't ...
2 votes
1 answer
155 views

Are the last 4 bytes in .SCL disk image files for Spectrum clones meaningful or spurious?

I recently added support for .scl images files to my Ghidra module which already supported .trd images. They are both representations of TR-DOS floppy disks as used mainly on Spectrum clones from ...
3 votes
2 answers
738 views

What file formats were used for binary executable files on later Sinclair ZX Spectrums?

The last official version of the Sinclair ZX Spectrum was the +3, released after the company was owned by Amstrad. It included a 3-inch floppy disk drive as used on other Amstrad computers. But even ...
5 votes
1 answer
294 views

Magnetic tape data preservation format

What 'virtual tape' image format is most suited for data preservation i.e. can store metadata like density and media type of original tape, presence of data past EOT marker, parity/ECC bits etc.?
13 votes
3 answers
2k views

What format is the (Timex) Sinclair ZX Spectrum SCREEN$/.SCR file

What format is the (Timex) Sinclair ZX Spectrum SCREEN$/.SCR file and how is the fore/background and attribute data encoded within this format?
6 votes
1 answer
3k views

Converting ZX Spectrum .ipf files to .z80 or .tzx for use in Fuse on RetroPie?

I have a 'perfect' set of ZX Spectrum games (in .ipf format) that I would like to use in EmulationStation (RetroPie) but the Fuse emulator doesn't recognize .ipf files. Are there any tools that will ...
31 votes
5 answers
5k views

What were the differences in floppy disk formats between Amiga and IBM/PC compatible computers?

The capacity in Amiga Old File System format (OFS, OS version 1.x) was 840KB, with the Fast File System ("FFS" (!)) introduced for OS 2.x onwards able to store 880KB. The PC format stored 720KB on the ...
21 votes
8 answers
4k views

Do the holes in Jacquard loom punched cards represent input data or program code?

I think they represent data because I feel it is a mechanical machine which is fully configured and the holes decide only that the thread related to each hole must be moved or not. Thus the holes ...
19 votes
2 answers
788 views

What was the end of line convention for text files on the 8-bit Commodores

A two part question: Did an agreed upon convention for end of line (EOL) within text files exist on the 8-bit Commodores? If there was a convention, what was it?
11 votes
1 answer
484 views

How to open a CorelDraw WI wavelet-compressed image

I have a large sample of .WI images I need to convert to e.g. JPEGs, but the format now seems defunct. The mimetype is image/wavelet. The compression algorithm was developed by Summus, a US company ...
15 votes
2 answers
1k views

IBM mainframe classic executable file formats

Most modern platforms have pretty well-defined file formats; e.g. Windows uses PE, Linux and BSD - ELF (previously a.out), macOS - Mach-O, AIX - XCOFF and so on. What were (are?) common executable ...
24 votes
5 answers
5k views

How well known and how commonly used was Huffman coding in 1979?

Infocom's Z-Machine, designed in 1979, compresses text using a basic 5 bit code which is not very efficient in practice, achieving maybe a 1.5:1 compression ratio. Huffman coding would be far more ...
4 votes
2 answers
506 views

What was the format for .OBJ files produced by M80.COM for CP/M?

When DOS released in 1981, the assembler that came with it produced .OBJ files that were OMF format. However there was a predecessor to it, M80.COM that ran under CP/M and also used .OBJ as the file ...
9 votes
1 answer
546 views

What are the best file formats for backup & emulation of retro game CDs? And why?

In other words, what are some factual, non-subjective reasons why you might choose (or avoid) a certain file format ? (For example, disk usage, audio accuracy, emulator compatibility, etc). I'm ...
6 votes
3 answers
520 views

Opening or converting GFA Basic files to something readable?

There is a bunch of GFA BASIC for Amiga files (the source code for Blender's ancestor, Traces, downloadable here: http://zgodzinski.com/blender-prehistory/) that I would like to peek at. Despite my ...
12 votes
1 answer
647 views

How are File Timestamps recorded in classic Mac OS?

When I save a file it has a 'Created At' and 'Updated At' Value saved as well. I would like to know HOW these values are saved? Are they saved as an integer representing a number of seconds since 1904?...
6 votes
3 answers
900 views

How can I debug a Mac OS Classic application?

I have a Mac OS Classic application (a game) that I want to "debug". It has data files in a unique format than I am attempting to reverse-engineer. I've made some progress with a hex editor, but ...
12 votes
2 answers
934 views

Origin of "tarball"

It seems to be common (at least among my section of the world's *NIX users) to refer to "tape archives" made with GNU tar or similar as "tarballs". I always thought this was a slightly odd choice, ...