Hi-speed loadings for zx81

[XavSnap]

Hi,

Somes Basic's error are also due to a wrong Carry on the A register.
Use the "SFC" command to awoid corrupt A register values!

...
SFC
JP $0206
...

[decicoder]

Good news. Otla tool for zx81 users is now available.

http://code.google.com/p/otla/downloads/list

Download last version otla_bin_win_2.2.0.zip (source is also available).

Wav examples that I posted here were made for the lowest speed (7350 bps). HIgher speeds are possible. May be you can experiment on real zx81 machine and comment results. Also if you see any bugs.

[yerzmyey]

decicoder:

>Good news. Otla tool for zx81 users is now available.
http://code.google.com/p/otla/downloads/list
Download last version otla_bin_win_2.2.0.zip (source is also available).
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Oh, man - that's a really good news.


>Wav examples that I posted here were made for the lowest speed (7350 bps). HIgher speeds are possible. May be you can experiment on real zx81 machine and comment results. Also if you see any bugs.
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I will test it surely. On the 7350 and maybe on fastest.
And I will let You know.

Also if I have any questions about using of the prog, I will let You know here. (At the moment I'm a t work).

Btw - prolly a stupid question but I want to be sure - 7350bps is 7,3 KiloByte per second?

[siggi]

Btw - prolly a stupid question but I want to be sure - 7350bps is 7,3 KiloByte per second?

BPS normally means "bit per second".

Siggi

[decicoder]

7350bps is 7,3 KiloByte per second?

In this case It means bits / s as Siggi said.
And the fast loading routine needs 8 bits to transmit a byte (other loading routines like MSX system takes 11 bits).
So 7350 bps is 918 bytes per second. That is an average speed. 'Zeros' are transmited faster than 'ones' , so real speed can be a little bit faster becuase normally programs have more zeros than ones.

How did the tests with this version of otla go? I think it's time to publish it to other systems users

[yerzmyey]

Of course I ment "bytes per second" but anyway I was wrong (as usual) 'cause it was all about BITS.
So about 1Kb/sec (that's transfer understandable for common people, hehe).
For now I have no additional infos about the subject as we prepare a concert in Prague (we will be playin music on ZX Spectrum computers - http://ay-riders.speccy.cz/ ) so preparations take whole my time.
But it should take no more than 1 week.

[BrunoFlorindo]

Excellent job decicoder! If you want another challenge try doing a zx81 version of Zinetrix. I wonder how impressed zx81 users would be if they could watch digitized video playing from tape or an mp3 player. Who needs IDE interfaces when you can load stuff at high speed through the old ear port? Hehe, I wish we had this stuff back in the days. How come no one thought of trying new modulation techniques instead of playing with baud rates?

[sirmorris]

How come no one thought of trying new modulation techniques instead of playing with baud rates?

Because we were 14 years old at the time??!!

Seriously, this is uber-smart stuff! Well done decicoder - you are officially on my very cool people list

[yerzmyey]

After many attempts I must state with sorrow that the program doesnt' work.
Most of times it shows "could not open the file" requester.
If it finally do something - it's can't be loaded on ZX81 (I test 16K).
And finally - the user-interface is tragic.
Any "project" ideas are strongly wrong - there should be regular LOAD P FILE and SAVE AS WAV, or SAVE AS MP3.
Instead of this we get some useless SBB files (projects) and there is no point to complicate all the matters so much.
I would suggest simple LOAD P and SAVE WAV instead of all of this.
Actually exactly like in ZX Spectrum version.
This one sadly is useless. :-\

[BrunoFlorindo]

Well, he tried to come up with something without being a ZX81 user and without having a ZX81 to test it, so we gotta thank him for that. I'm sure that with constructive criticism and positive motivation he or someone might come up with something better. A lot of ZX81 users don't use tape anymore but I still think the idea of fast loading on the ZX81 (either via cassette, cd, pc or your favorite mp3 player) should be explored.