Sinclair ZX80 / ZX81 / Z88 Forums

Can I have a link to the topic, please?

C

Sure!

http://www.worldofspectrum.org/forums/s ... hp?t=31362

http://www.fruitcake.plus.com/Sinclair/ ... w_ZX80.htm
http://www.fruitcake.plus.com/Sinclair/ ... w_ZX81.htm

The only reason why later Spectrum models can do it without an Interface 2 is simply because they allow the all-ram mode (you can page your own code at address 0 and use the full 64K if wanted).

A very old thread but I recently played with ZX Slowloader and it worked pretty well. It does most of the conversions for you, though it stumbles on some graphics characters, especially if you use CODE/CHR$ combinations.

I did have issues with using actual hardware. No matter what I did with volume level, my 48K Spectrum could not load in the ZX81 program from audio. On the EightyOne emulator, I could load a ZX81 audio file (i.e. .wav) and it worked for all the ones I had. How finicky is the Spectrum with audio levels? All of my Spectrum-specific audio files load in perfectly fine into my 48K Spectrum, but when ZX Slowloader then runs and looks for the ZX81 program it never starts to find anything to load.

Anyone have good experience with ZX Slowloader?

bwinkel67 wrote: ↑Mon Feb 13, 2023 2:49 am Anyone have good experience with ZX Slowloader?

Depends what SLOWLOADER you use.
My very first ZX81 emulator is sometimes called SLOWLOADER too, but is a complete emulator.

Better to use my 2020 emulator SP-2-ZX81.
First version has converters from old emulator and manual, latest version only updated version.

So I'm using the 1982 ZX Slowloader by East London Robotics that converts ZX81 BASIC to Spectrum BASIC. The conversion works on the EightyOne emulator set to 48K Spectrum loading a ZX81 audio file, but not on actual hardware (well, it runs but can't seem to recognize any ZX81 audio files). I don't want emulation, just a way to convert from one BASIC to another...well, in reality, I just wanted to play with the software to see how well it works.

bwinkel67 wrote: ↑Mon Feb 13, 2023 8:42 am So I'm using the 1982 ZX Slowloader by East London Robotics that converts ZX81 BASIC to Spectrum BASIC. The conversion works on the EightOne emulator set to 48K Spectrum loading a ZX81 audio file, but not on actual hardware (well, it runs but can't seem to recognize any ZX81 audio files). I don't want emulation, just a way to convert from one BASIC to another...well, in reality, I just wanted to play with the software to see how well it works.

Covert BASIC into BASIC will leave you with manual conversion for not compatible BASIC, like SCROLL, UNPLOT.
Besides that, PLOT on the ZX Spectrum is a whole different resolution.

SLOWLOADER also converts ZX81 ASCII to ZX Spectrum ASCII.

dr beep wrote: ↑Mon Feb 13, 2023 11:15 am Covert BASIC into BASIC will leave you with manual conversion for not compatible BASIC, like SCROLL, UNPLOT.
Besides that, PLOT on the ZX Spectrum is a whole different resolution.

Yup, that part worked actually pretty well, with just some commands needing to be re-mapped. As you say, PLOT/UNPLOT (equiv being PLOT/PLOT OVER 1) don't work due to different resolution and coordinate system.

But that's not my question. I got it to work flawlessly in the EightyOne emulator in 48K Spectrum mode. I'm not looking for a solution to convert ZX81 to Spectrum BASIC, I'm trying to explore this cool 1982 software and can't get it to see the ZX81 wave files when run on a real 48K Spectrum (i.e. the way someone would have used it in 1982). Those same wave files load in perfectly well on a real Timex Sinclair 1000.

I've tried to amplify the ZX81 audio in Audacity but still nothing. The signal is a clean EightyOne generated .wav file, so it's not bad audio. Is there something weird that EightyOne does with generated audio that would cause it to work on a TS1000, but the ZX Slowloader is expecting something just a bit different when run on a 48K Spectrum?

My converter is based on (a) slowloader. I think there are several slowloaders.
What I converted then was no problem ever.

In terms of the hardware, the tape input circuitry in the ZX Spectrum ULA is more sophisticated. It’s designed to make loading easier by being less sensitive to noise in the signal. The ZX81 is more primitive in this respect. Both the ZX81 and the ZX Spectrum need a reasonable loud signal.

Note that with all tape operations on both computers, all the timing is done in software.

I’m not aware of Eightyone doing anything weird to the tape signals. But it’s been a while since I tried…

Do you have a real tape to try? Or another source of a ZX81 tape recording to try?

Mark

1024MAK wrote: ↑Mon Feb 13, 2023 5:16 pm Note that with all tape operations on both computers, all the timing is done in software.

I'm in the US...I wonder if that's adds any difference. It's running on 9V DC...would it be a 50 vs 60 Hz issue? When generating the .wav files I think EightyOne was set to ZX81, vs TS1000. Should I set it to TS1000 and regenerate the audio files. (Btw, I usually use EightyOne in ZX81 mode because when loading .p files, in TS1000 mode, it doesn't automatically do the Load "" for me -- version 1.26 of EightyOne).

1024MAK wrote: ↑Mon Feb 13, 2023 5:16 pm Do you have a real tape to try? Or another source of a ZX81 tape recording to try?

I could try saving a small program from my TS1000 and then use that to load into the Spectrum via ZX Slowloader to see if that makes a difference.