ZX Spectrum file formats

Z80Em defines &BA0 and &BA1 for Z80 and SNA snapshots respectively. The documentation from the (very old) demo version I have available claims that both of these are officially allocated with Acorn, and the list from the ANS Filebase lists those two as officially allocated, as well as &11D for TAP files, however the File Types list lists the allocation status of both formats as Unknown. In addition, the page also lists &1B8 for TZX files, however I can’t find any information about this file type. Can anyone confirm for certain whether or not all of these are officially allocated?

Initially I was allocated these by Alan Glover in 2004
“The file attached was empty, but going by the subject line I’ve allocated TZX as 0×1b8 and VOC as 0×1b7.”
but he made an error “I was assigned filetype 1B7 for ArmBob by Alan Glover on 11/03/2004”

so “Please shift your allocations up by one, ie 0×1b9 for TZX and 0×1b8 for VOC”

so these are the definitive allocations for Z80Em:

Set File$Type_BA1 SNA
Set File$Type_BA0 Z80
Set File$Type_11D TAP
Set File$Type_1B9 TZX
Set File$Type_1B8 VOC

6502Em uses these – I’m not sure the BBC one is official though :)
Set File$Type_BBC BBCSnap
Set File$Type_B22 DFSImage

I have a vague recollection that ‘BBC’ was used by 65Host or maybe 65Tube in some way. That probably makes it official, although perhaps not for the exact same purpose as 6502Em.

Thanks, I’ve updated the list with this information.

I have a vague recollection that ‘BBC’ was used by 65Host or maybe 65Tube in some way. That probably makes it official, although perhaps not for the exact same purpose as 6502Em.

It is used by 65Host, but it’s used there for BBC ROMs rather than snapshots.

Set File$Type_1B8 VOC

Is this the Creative Voice VOC format, or a different one? I’ve seen file type F96 used for VOC files as well, so if they’re both the same, which one should be preferred?

Yes, it’s the Creative Voice VOC format. Is “F96” official? 1B8 is at least officially allocated

ps have you seen http://web.archive.org/web/20041104075131/http://www.seedwiki.com/page.cfm?wikiid=6955&doc=filetypes

It would be helpful if the File Type list here could be updated to add entries for those types which have been allocated, but are not public (marked as such)

Although TooLateNow™ I’ve advocated before that all allocations should be made with a “Immediate publish” option, and at most a month’s delay (extensible per month upon request).

The assumption of privacy forever is counter-productive, and has led to duplicate allocations (e.g. PPD).

Privacy is bollocks anyway. Maybe back in the Acorn days when you didn’t want your competitor to know you were just about to release something better…

…but these days, it’s just a three-hex type with an (up to) eight character name. If it’s “sensitive” then it isn’t necessary to include any information on who made the registration. Indeed, all we really need to know is that it’s a known type.

These days, should requests include an optional MIME type for things that may be other-OS-aware? Or perhaps a note of the expected file extension?
Example: &B27 → “OvnPro” → .dpd

and has led to duplicate allocations

I don’t know if any/which are actually allocated, but there are numerous types of Teletext frame out there. A raw 40×25 dump (1000 bytes), CC frame (chapter zero dump, 1024 bytes), CC/Octopus/My¹ frame (1080 bytes), Page dump with all ghost rows (2048 bytes)… and enough different filetypes that my editor recognises types &112 (GC/My), &80B (CC), &B12 (Octopus), and will try some simple tests (length match, no control codes) on files of other types.

¹ My Teletext software uses the same file format and filetype as the original Ground Control software (I’m just going to guess that &112 is not allocated!) because it was originally written to replace the naff software supplied by GC with their receiver.
To put this into context, the floppy came with two versions. One was for RISC OS, the other for Arthur!

www.seedwiki.com/page.cfm?wikiid=6955&doc=filetypes

What the hell is Archway2? It has over 40 filetypes!

I see lots of duplicated different types, too, down in the &1xx range.

There is a case for not revealing information about filetype allocations while development is going on, as public knowledge might cause pressure to be exerted, or even to lose sales of a product that is about to be superseded. (Sales, these days? Ha!)

There is also a case for not getting filetypes allocated until the product is ready to ship. Says me, who has had various allocations (not filetypes, but allocations nevertheless), thinking I was about to release, and then time has passed… It’s an easy trap to fall into.

I think it would be reasonable to issue temporary allocations for development, and if not renewed, they go back in the pot. Couple of renewal opportunities, then that’s it.

as public knowledge might cause pressure to be exerted,

Which is why I suggested not providing details of who made the allocation. The types database doesn’t need to know that, it just needs to know what filetypes are known to the registration system.

Says me, who has had various allocations

Not just you, I’m sure. ;)

A better idea might be to have allocations that auto-expire if not confirmed… but this is RISC OS. Auto-expire likely means “somebody reads the allocation dates for each type”.

Edit: Stuart beat me to it. Well, that’s what I get for fiddling with my video editor while writing. :-)

Why not have an option to ask for it to be kept confidential for a short period, say 6 months?
Also I think ROOL should announce now that in one years time they will publish all the allocated (but still confidential) names but not say who by, unless requested to delete and free them up.

Why not have an option to ask for it to be kept confidential for a short period

Yeah that’s what I said, and the default should be ‘publish immediately’.

And in the case of established file formats (from the real world) there’s no argument for keeping those secret.

in one years time […] publish all the allocated (but still confidential) names

I’m not necessarily disagreeing, but I’m not sure what value there is in knowing that &123 (say) is officially “Foobar”. What’s a Foobar? Are you calling for the file format to also be published?

As I say, for standard file formats it’s a no-brainer.

Stuart suggested

temporary allocations for development

That’s what &0xx is for.

For anyone who cares, my list of allocations, publicly used and those that were in development, are here:

https://usenet.gerph.org/Allocations/Allocations.txt

There are other allocations that exist that aren’t in that list, I think, like the FanController and Pyromaniac specific things.

There are two additional filetypes registered ‘recently’ (Oct 2020)…

• FileType A65 “JPEG2000” (no space or hyphen to obey 8-char limit)
• FileType A66 “WebP”

which were both expected to be published in the latest set of filetypes.

Oh, and one registered in May 2020…

• FileType F74 “YAML”

Which is also a general use one so I assume is also in the published list.