Spectrum Computing

Ast A. Moore wrote: ↑Sat Jul 07, 2018 1:58 pm That aside, I don’t quite get the idea behind this exercise. We simply have a series of tones of different frequencies, which don’t translate into data. The only “loader” effect is the border changing color each time the waveform crosses the zero point.

Is it 'Oh Susannah' you don't see the point of, or musical tape loaders in general?

My understanding is that Imperial March and Happy30th do translate into bytes and are worthy of a ZXDB ID, but based on what you say 'Oh Susannah' is only a loader followed by everyday notes that do not translate into bytes and shouldn't have an ID. Sound about right?

I think I’m missing something here.

I doubt it!

R-Tape wrote: ↑Sat Jul 07, 2018 2:25 pm Is it 'Oh Susannah' you don't see the point of, or musical tape loaders in general?

I have nothing against “Oh, Susanna”—it’s one of the tunes my wristwatch plays! (Yup, it’s from the 80s, and sill going strong).
I just don’t see how this is a “loader.” It doesn’t load anything; just toggles the border color based on the state of the EAR port. You can feed it any audio signal—even a complex one—and it’ll more or less do the same.

R-Tape wrote: ↑Sat Jul 07, 2018 2:25 pmMy understanding is that Imperial March and Happy30th do translate into bytes and are worthy of a ZXDB ID, but based on what you say 'Oh Susannah' is only a loader followed by everyday notes that do not translate into bytes and shouldn't have an ID. Sound about right?

Yeah, in a nutshell.

For I come from Alabama with a banjo on my knee . . .

Maybe I'm not quite getting what you're saying here, but the 'Oh Susanna' thing definitely loaded something for me:

djnzx48 wrote: ↑Sun Jul 08, 2018 3:43 am Maybe I'm not quite getting what you're saying here, but the 'Oh Susanna' thing definitely loaded something for me:

I think you mixed up the tapes and left Phil Collins’ But Seriously in the tape player. A rookie mistake.

So what exactly makes this 'not a loader' then? It looks like one to me.

djnzx48 wrote: ↑Sun Jul 08, 2018 10:56 am So what exactly makes this 'not a loader' then? It looks like one to me.

Holy moly! I originally only managed to have a precursory look at it, and it didn’t look to me it it actually loaded anything. I just tried to play back the audio file in Fuse and . . .

Seriously, man, I thought you were joking with that screen shot.

My apologies. This requires serious investigation.

[mention]R-Tape[/mention] I kid you not. It really friggin’ loads that screen while playing the goddamn tune!

P.S. My point about the use of the IN F,(C) instruction still stands, though (don’t press any keys while the screen is loading), but doesn’t make me any less wrong on the whole loader vs. not-a-loader front.

It does load in Fuse..... yup.

Options --> Media. Untick fast loading.

Drag the .wav file into the emulator and it will load in the first part and stop.

Media --> Tape --> Play (or press F8) and it will load in the rest of the file.

Impressive!

Thanks Mat et al. Impressive indeed. I'm going to need to go to a darkened room with a flannel on my forehead trying to work out how this actually works.

Now that we know the .wav works, can anyone make a functioning TZX from it? 4Mb is a sizeable file.

R-Tape wrote: ↑Sun Jul 08, 2018 2:08 pm Thanks Mat et al. Impressive indeed. I'm going to need to go to a darkened room with a flannel on my forehead trying to work out how this actually works.

I think I know how it works. I theory, a least.

R-Tape wrote: ↑Sun Jul 08, 2018 2:08 pmNow that we know the .wav works, can anyone make a functioning TZX from it? 4Mb is a sizeable file.

Sure. It’s still 636K, though. (Grab quickly. The link expires in a few days.)

Below is the comment I've put in the spreadsheet to add to ZXDB. I think it betrays the fact that I don't really understand it but is probably good enough. If someone wants to suggest something better/more accurate (yet concise) please do so.

"Uses tape loading sounds to play "Oh Susannah" while loading graphics."

Ast A. Moore wrote: ↑Sun Jul 08, 2018 2:17 pm Sure. It’s still 636K, though. (Grab quickly. The link expires in a few days.)

Ta! I'm not sure why mine didn't work

R-Tape wrote: ↑Sun Jul 08, 2018 8:18 pm Ta! I'm not sure why mine didn't work

It didn’t work for me when I tried it with fuseutils either, so I took a different approach. I loaded the WAV into Fuse and then saved it as a TZX.

Beyker, a member of the Spanish Telegram group tested the WAV on real hardware, and it works, in fact, he noticed that you can stop the load at any point and resume.

druellan wrote: ↑Sun Jul 08, 2018 10:01 pm he noticed that you can stop the load at any point and resume.

True, but most of the time it’ll mess up the picture, as some data will likely be lost. (You can try it with Fuse as well, using the play/pause command. That way, no data will be lost.)

That’s one of the modifications made to the loaders, both standard (Patrik Rak’s version) and OTLA—they don’t terminate after a timeout. There’s no error checking per se; the loader terminates only when the byte counter runs down. As a result, you can feed it different audio sources—including normal audio files—and they will display something (fairly random garbage) on the screen until the entire display file is filled up.

I found a thread on W*S about this loader: https://www.worldofspectrum.org/forums/discussion/22295

It's a shame about the dead source code link. No one happens to have a copy of the source (musical_source.zip) do they?