Can ZX81 load progs directly from MP3 player?

Discussions about Sinclair ZX80 and ZX81 Hardware
User avatar
yerzmyey
Posts: 1240
Joined: Thu May 15, 2008 10:11 am
Location: Rubber Planet
Contact:

Can ZX81 load progs directly from MP3 player?

Post by yerzmyey »

Hi there.

My question is, if enobody tried yet to load progs directly from MP3 player to ZX81?

On Spectrum You need also an amplifier because signal from the MP3 player is too weak. So - does ZX81 need an amplifier too?

To use only ZX81 with a small player instead of huge hi-fi sets.

Greetz.
IN NIHILUM REVERTERIS - a big text-adventure game for ZX81: http://tiny.pl/g2m6m
"MONOCHROME" issue 5 - (Spring 2014) free paper/PDF magazine about ZX81: http://tiny.pl/q2m44
ZX81 COMPETITIONS 2007/2009: http://zx81.republika.pl/
sirmorris
Posts: 2811
Joined: Thu May 08, 2008 5:45 pm

Re: Can ZX81 load progs directly from MP3 player?

Post by sirmorris »

You would probably need to have a high bitrate too. I have failed to load Apple programs which have been MP3'd - though if I was completely honest I should say that I didn't try very hard ;)
User avatar
Andy Rea
Posts: 1553
Joined: Fri May 09, 2008 2:48 pm

Re: Can ZX81 load progs directly from MP3 player?

Post by Andy Rea »

It All depends on the output level of your MP3 player i have found the Cheap ones usually give a higher level output than the more expensive ones, as for MP3's and high bit rates doesn;t really make the file that much bigger because zx81 tape data is highly compressable, even more so if you sample it and use some filtering before turning it into an MP3.

having said all that i don't use mp3 and rarley even use a real tape, when ZX81-ing i've always go a laptop near by and use that along witt wintzx to load progs

Hope that helps

Reagrds Andy.
AFK
User avatar
yerzmyey
Posts: 1240
Joined: Thu May 15, 2008 10:11 am
Location: Rubber Planet
Contact:

Re: Can ZX81 load progs directly from MP3 player?

Post by yerzmyey »

Thx for the infos, I appreciate it.

Well, as for loading from PC, I use it too but I don't use laptops at all (maybe it's time to change my preferences) and I was thinking about some taking ZX81 to some parties and stuff, where taking huge PC (or big amplifier) would be a problem.
I considering also checking out some CD players.

Anyway I agree - probably at home I will use PC sound-card too.

As for bitrate, I presume that 192Kbps will be sufficient.

Thx again, guyz.
IN NIHILUM REVERTERIS - a big text-adventure game for ZX81: http://tiny.pl/g2m6m
"MONOCHROME" issue 5 - (Spring 2014) free paper/PDF magazine about ZX81: http://tiny.pl/q2m44
ZX81 COMPETITIONS 2007/2009: http://zx81.republika.pl/
User avatar
BrunoFlorindo
Posts: 289
Joined: Sat May 10, 2008 2:46 am
Location: Anaheim, CA, USA

Re: Can ZX81 load progs directly from MP3 player?

Post by BrunoFlorindo »

Replying to the original question, yes they can. But instead of messing around with slow baud loading, check this out:

http://code.google.com/p/otla/
http://www.youtube.com/watch?v=Q4xyDdIdVKk
http://personal.auna.com/casariche/otla/otla1.htm (in Spanish)

The conversion isn't automatic, but it's easy to do. The project has had success with the Spectrum and clones, Amstrad CPC and MSX. The author has expressed interest in helping ZX81 users, and I've invited him to this forum.
I strongly recommend this to ZX81 users who don't have or don't want to use IDE interfaces, but would appreciate fast loading.

Some of the questions he has:
How precise are the ZX81 timings? Does it have contended memory problems like the Specrum?
What are the most common snapshot formats?
What is the recommended address for a loading routine?
Etc.
User avatar
yerzmyey
Posts: 1240
Joined: Thu May 15, 2008 10:11 am
Location: Rubber Planet
Contact:

Re: Can ZX81 load progs directly from MP3 player?

Post by yerzmyey »

I agree that turbo would be better. But I don't know if it's possible on ZX81.

I use this software-turbo on Spectrum for quite some time. I achieved about 19Kb per sec if I recall. But it doesn't work every time - and it likes *.z80 snaphots, not regular TAPs (a pity).

Anyway such a thing for *.p files would be really good. :)
IN NIHILUM REVERTERIS - a big text-adventure game for ZX81: http://tiny.pl/g2m6m
"MONOCHROME" issue 5 - (Spring 2014) free paper/PDF magazine about ZX81: http://tiny.pl/q2m44
ZX81 COMPETITIONS 2007/2009: http://zx81.republika.pl/
User avatar
yerzmyey
Posts: 1240
Joined: Thu May 15, 2008 10:11 am
Location: Rubber Planet
Contact:

Re: Can ZX81 load progs directly from MP3 player?

Post by yerzmyey »

BrunoFlorindo wrote: I strongly recommend this to ZX81 users who don't have or don't want to use IDE interfaces, but would appreciate fast loading.
That would be me. ;)
IN NIHILUM REVERTERIS - a big text-adventure game for ZX81: http://tiny.pl/g2m6m
"MONOCHROME" issue 5 - (Spring 2014) free paper/PDF magazine about ZX81: http://tiny.pl/q2m44
ZX81 COMPETITIONS 2007/2009: http://zx81.republika.pl/
sirmorris
Posts: 2811
Joined: Thu May 08, 2008 5:45 pm

Re: Can ZX81 load progs directly from MP3 player?

Post by sirmorris »

That's all very nice - but you need to load the loader first :)

You could put it into ROM of course - but that's a hardware upgrade too!

I recommend one of these:

Image

:ugeek:
User avatar
yerzmyey
Posts: 1240
Joined: Thu May 15, 2008 10:11 am
Location: Rubber Planet
Contact:

Re: Can ZX81 load progs directly from MP3 player?

Post by yerzmyey »

Oh! May I ask what is that, how does it work, where to buy it ;) and any other required details?
IN NIHILUM REVERTERIS - a big text-adventure game for ZX81: http://tiny.pl/g2m6m
"MONOCHROME" issue 5 - (Spring 2014) free paper/PDF magazine about ZX81: http://tiny.pl/q2m44
ZX81 COMPETITIONS 2007/2009: http://zx81.republika.pl/
sirmorris
Posts: 2811
Joined: Thu May 08, 2008 5:45 pm

Re: Can ZX81 load progs directly from MP3 player?

Post by sirmorris »

This is my MMC interface that I designed and built.

It's a nasty hacked-up board but it is only v1.0.. I'm sure I'd do a much better job of it now!

Details here including schematic and code:

http://www.robsonfamily.dsl.pipex.com/mmc/mmc.htm

I was being a bit cheeky before - this requires a loader too, plus expanded RAM in the 8-16k area.

I do have a design in my head which would use a microcontroller to DMA the data, which would indeed be plug and play.. :geek:
Post Reply