Suggestion: Add PZX files to the database

[arjun]

I was wondering if there would be any interest in adding PZX file versions of all the games to the database. Most programs already have TAP and TZX versions so this would be yet another tape format for users to choose from. Why PZX? Well, it's the superior tape format and is regarded favourably by many emulation authors. It's also supported by the most popular emulators in the scene - Fuse, SpecEmu, ZXDS, ZEsarux, Zero etc.

Unfortunately, PZX has never really gained traction despite it being the better format because of lack of support from previous archive maintainers (TZX Vault was it?). In their defense, they probably lacked the tools to create PZX files as well as they did for TZX.

Anyhow, I thought it would be awesome if we could get some PZX support in the archive. Patrik Rak (the creator of PZX) has some windows tools on his site. The important one being TZX2PZX. If this could be run in an automated way for all the TZX files in the archive, it should be fairly easy to get PZX versions of the files with minimal effort.

I dunno how the archive process actually works, so any comments on why this would be a good thing or bad thing or unnecessary addition would be welcome.

[Einar Saukas]

What's the advantage in doing so?

If PZX files are just auto converted from TZX, then just storing TZX would be enough.

[arjun]

What's the advantage in doing so?

If PZX files are just auto converted from TZX, then just storing TZX would be enough.

PZX files are a simpler format and easier to implement in emulators and tools. There is no real advantage over TZX in terms of preservation TBH because both do the job. But having PZX files actually available in the real world will help popularize the format. It's kind of chicken and egg right now, because while implementing PZX is easy, the lack of real world data holds it back from being widely adopted from both end user and tools developer perspective. There were a number of discussion on the clunkiness of the TZX format (on WoSF), which led to this format. I can dig up those threads if it helps shed light/context on the usefulness of PZX format.

Not sure what you mean by "auto converted from TZX".

[cmal]

I’d be interested in knowing more about the PZX format and what advantages it has over TZX. If I’m not mistaken, I think PZX format is supported by @bob_fossil ’s LFN browser. Is that an accurate statement?

[bob_fossil]

I’d be interested in knowing more about the PZX format and what advantages it has over TZX. If I’m not mistaken, I think PZX format is supported by @bob_fossil ’s LFN browser. Is that an accurate statement?

PZX file support in the browser requires a ZX-UNO - it won't load them on a real Spectrum. As has been said, PZX is a much simpler tape format, so it was less work to implement that rather than TZX on the ZX-UNO.

[Einar Saukas]

PZX files are a simpler format and easier to implement in emulators and tools. There is no real advantage over TZX in terms of preservation TBH because both do the job. But having PZX files actually available in the real world will help popularize the format. It's kind of chicken and egg right now, because while implementing PZX is easy, the lack of real world data holds it back from being widely adopted from both end user and tools developer perspective. There were a number of discussion on the clunkiness of the TZX format (on WoSF), which led to this format. I can dig up those threads if it helps shed light/context on the usefulness of PZX format.

I'm not criticizing the PZX format. It looks great.

My point is, the advantage of PZX is that it's easier for emulators to support in comparison to TZX. However all emulators already support TZX. Also any emulator that may be created in the future will also have to support TZX anyway, since so many TZX files exist. It's kinda too late for this advantage.

What other reason we have?

Not sure what you mean by "auto converted from TZX".

You wrote yourself "the important one being TZX2PZX".

AFAIK nobody is preserving tapes directly in PZX format. Everything is preserved as TZX, then auto converted to PZX.

Why add tens of thousands of auto-converted PZX files to the archive (and have to manage them afterwards), when people can convert any TZX file themselves to get exactly the same result?

[arjun]

My point is, the advantage of PZX is that it's easier for emulators to support in comparison to TZX. However all emulators already support TZX.

Not really. Zero, for eg, doesn't support TZX natively. It supports it by using TZX2PZX DLL in the background (and there are a couple of other emulators that do the same, I believe). It supports PZX natively though. The reason emulators have to support TZX is that PZX files aren't available in the first place, hence this request. If we had a world with choices between TZX and PZX, many would prefer to implement the latter simply because it's a better format. Currently, we don't even have that choice. Everyone is forced to implement TZX because it's the de facto and only available tape format in the archive (apart from TAP). And anyone who's implemented TZX will know the pain they have to go through for this.

Why add tens of thousands of auto-converted PZX files to the archive (and have to manage them afterwards), when people can convert any TZX file themselves to get exactly the same result?

I should clarify this: TZX2PZX is only available as a C++ source code. You will need to create your own executable for whichever platform you're running on. For Zero, I had to create a DLL by modifying the source code (windows only) so that I could invoke it while running the emulator. Not a huge deal but a decently high barrier for anyone trying to integrate it into the tool of their choice. For non-technical users, this is probably a deal breaker.

I understand the reluctance to add more files to the archive, but if we can add magazine scans, multiple versions of TZXs, gifs, surely adding a PZX version of the file (converted either from the existing TAP or TZX version of the file) isn't that much of a stretch. Having said that, as I said before, I don't know the effort required for the archive preservation so will defer to your thoughts on this.

[firelord]

...
The important one being TZX2PZX. If this could be run in an automated way for all the TZX files in the archive, it should be fairly easy to get PZX versions of the files with minimal effort.
...

I think there is no need to convert everything and upload them to the server. We could use live conversion.
This is what I do in my htm2tap. I write Basic code and create a text file . In the server (using exec or system) I run the command zmakebas my.txt my.tap and I get a TAP file. Then I send to the client that TAP file.

There could be a button named PZX where it just converts server-side the TZX.
Of course it would be better to do it client-side but will need the windows program to be converted to wasm or vanilla javascript (eg with emscripten).
There are also load and security issues to consider.

Btw, I'm still using z80,TAP and SNA files because the emulators that cover my needs are DOS or Javascript mostly...

[8BitAG]

For the end user, there doesn't seem to be any real reason to switch from TZX files to PZX. And ultimately I'm only going to choose an emulator that has TZX support, so it's not going to be any easier for the emulator author. It's a neater file format but I'm struggling to see how you'd sell the benefits for the average person involved in the retro community. Why should *we* switch to using PZX? There's enough confusion on file formats as it is.

[arjun]

For the end user, there doesn't seem to be any real reason to switch from TZX files to PZX. And ultimately I'm only going to choose an emulator that has TZX support, so it's not going to be any easier for the emulator author. It's a neater file format but I'm struggling to see how you'd sell the benefits for the average person involved in the retro community. Why should *we* switch to using PZX? There's enough confusion on file formats as it is.

I don't see why the end-user cares if the file is TZX or PZX or TAP so long as it works for them?

[arjun]

We could use live conversion.

It could work, but I'm guessing this is actually more work on the backend to maintain and fix issues in, ultimately. And the load+security concerns you pointed out.

[8BitAG]

I don't see why the end-user cares if the file is TZX or PZX or TAP so long as it works for them?

I don't. Which is why I won't ever be downloading PZXes. Or creating them for new games or recovered software. The existing formats are fine for my needs. I would presume this is why others haven't made the switch to PZXes either.

What is the benefit to me of using a PZX?

[arjun]

I don't. Which is why I won't ever be downloading PZXes. Or creating them for new games or recovered software. The existing formats are fine for my needs. I would presume this is why others haven't made the switch to PZXes either.

That's fine. I dunno why you're being so aggressive about this. I'm not asking TZX to be removed from archives or drop support for it from other people. All I'm asking is allow PZX a chance by adding support for it in the archives and other folks who are interested in the format. *shrug*

What is the benefit to me of using a PZX?

None, clearly.

[8BitAG]

If it's coming across as aggressive then that is simply down to the difficulties communicating emotions in the written word. It's certainly not my intention. I was just enquiring what would the benefit of PZX be to anyone who isn't an emulator author. (That's a very niche subset). Your comments seem to indicate that there simply isn't any; as does the FAQs on Patrik's site. Which is fine, but it does probably explain why there hasn't been much take up for the format and perhaps makes it difficult to justify the effort of putting something in place to include them in a site like this.

[SkoolKid]

At the moment there don't seem to be any PZX tapes anywhere in ZXDB. What would happen if someone created a new game/utility/whatever and made it available only in PZX format? Would it be accepted into ZXDB as-is, or would it need to be converted into a TAP or TZX first?

If no conversion from PZX would be required, I think the thing to do is flood the market with new titles that are available in PZX format only. At least then PZX will get some sort of foothold.

[AndyC]

I almost can't believe nobody has posted this already:

[Timmy]

I agree there might be a need for a format other than TZX that is easier/faster to load, and can be easily be used by tools.

But I feel like we already have those snapshots formats like SNA and Z80.

In fact, a lot of my tooling is using the SNA format.

So I agree we might need more snapshot files, but it doesn't necessary need to be in the database.

[arjun]

If it's coming across as aggressive then that is simply down to the difficulties communicating emotions in the written word. It's certainly not my intention. I was just enquiring what would the benefit of PZX be to anyone who isn't an emulator author. (That's a very niche subset). Your comments seem to indicate that there simply isn't any; as does the FAQs on Patrik's site. Which is fine, but it does probably explain why there hasn't been much take up for the format and perhaps makes it difficult to justify the effort of putting something in place to include them in a site like this.

You're right, it's mostly a concern for emulator and tool authors (and archive maintainers in this case). It's a bit frustrating that we all seem to agree that PZX is the better format for future emulator (new emulator authors rise up every day!) and tool developers but can't seem to overcome the hill of TZX because that's the only available option right now. I guess that's the power of legacy and I can see now why M$ makes some of the decisions it does.

EDIT: Actually there is one thing about PZX that might benefit end-users. Since the PZX format is easier to understand and implement (than TZX), there are less chances of people creating bad PZX that may fail to load in other emulators and/or tools. You might say it's a skill issue, but really there have been enough discussions on this (TZX implementation difficulties) by far more skilled coders than me on this, so it's more than just that clearly.

[arjun]

At the moment there don't seem to be any PZX tapes anywhere in ZXDB. What would happen if someone created a new game/utility/whatever and made it available only in PZX format? Would it be accepted into ZXDB as-is, or would it need to be converted into a TAP or TZX first?

Good question and something the archive maintainers can answer better I suppose. My reaction is to say it can be accepted as PZX only if the format becomes popular. Which leads to ...

...I think the thing to do is flood the market with new titles that are available in PZX format only.

Unfortunately, I doubt anyone will supply PZX only files for fear of losing a significant subset of their target audience who mostly are aware of only TZX format. Interestingly all the well known emulators actually support PZX out of the box. It's just that many end users don't seem to be aware of it and I don't blame them. The archive support determines which files end users get to see and use after all.

[lfaria]

I'm loving this thread!
It reminds me the old discussions over TZX v1.13 vs. TZX v1.20 elsewhere...

The archive already stores several different preservation file formats:
- some representing Tapes
- some representing (memory) Snapshots
- some representing Disks
- some representing Cartridges / ROMs
Some titles even combine multiple types (I'm thinking about Shadow of the Unicorn, ROM + Tape)
Why not one more file format? Well, I've no idea...
...(what if the Codemasters CD was not denied?)...

Back in those old days (which today look like the Medieval Era) most developers / preservers agreed that TZX v1.13 couldn't represent
all tapes, with some titles being used as special "cases".
Before Patrik Rak came up with PZX, TZX format v1.20 was thus proposed... and quickly dismissed
by several, as being (unnecessarily) too hard to implement (as if v1.13 wasn't hard enough already).

Then came PZX, a much simpler file format that could preserve all tapes.
To this day, the archive still avoids TZX v1.20 files... and PZX files... therefore storing some titles only as TAP or Snapshot files instead of a pristine representation of the original tape (there's a publicly accessible "vault" holding v1.20 versions of several titles).

So, the pristine representations of those "special" cases aren't easily available (most are preserved, thankfully), even when they're not denied nor MIA.
As most of us know, several emulators already have support for PZX files (of course, "frozen" ones won't get support for it added)
But do "normal" users care? I'm sure they don't. (they don't need to argue either way, either, I guess)

[akeley]

If pzx was a format which would work on various DIV-style devices attached to real hardware, well, now that would get my attention...

[SkoolKid]

A few days ago I was playing around with trace.py (in SkoolKit) generating snippets of tape-loading noise, and I found that, even using the ROM save routine, not every 0-pulse is exactly 855 T-states, and not every 1-pulse is exactly 1710 T-states. Which means that the vast majority (probably all) of the TAPs, TZXs and PZXs out there are just wrong.

To correct this, I'm considering developing my own new tape format that is perfectly T-state accurate. But I'm not sure what to call it. Top candidate names at the moment are "SZX" (SkoolKid's ZX) and "RZX" (Richard's ZX), assuming they're not already taken. What do you think?

[Lee P]

To correct this, I'm considering developing my own new tape format that is perfectly T-state accurate. But I'm not sure what to call it. Top candidate names at the moment are "SZX" (SkoolKid's ZX) and "RZX" (Richard's ZX), assuming they're not already taken. What do you think?

How about "T-state Accurate Pattern"?

[lfaria]

To correct this, I'm considering developing my own new tape format that is perfectly T-state accurate. But I'm not sure what to call it. Top candidate names at the moment are "SZX" (SkoolKid's ZX) and "RZX" (Richard's ZX), assuming they're not already taken. What do you think?

You're joking: you can generate a TZX or PZX without assuming that all "1"s (or "0"s) are the same length.
Of course, without using the "quick and dirty" TZX block 10 and friends.
It's just longer and more convoluted (and yes, the usual TZX generator tools also attempt this quick exit).