Page 1 of 1

O.T.L.A. (high speed loader) works for me too !

Posted: Wed Sep 07, 2011 12:47 am
by zx80nut
By building a simple circuit to ensure a clean loud signal is transfered to the ZX81 (a comparator operating with a bit of hysteresis) I have also successfully managed to get OTLA working VERY well.

It works with my ZX80 clone, with the ZX81 conversion on it. I will check on the ZX81's but there is no reason why it shouldn't work.

So far, I can reliably get the 11025bps transfer speed.

So, the bigger programs such as Manic Miner loads in 11.5 seconds and 3D Monster Maze in 10.5 seconds !

I may be able to get the full speed 14700, but I haven't tried tweaking the circuit - it was a quick 5-minute knock-up on a solderless breadboard with crocodile clips connecting the jack plugs!

I have seen elsewhere on this forum that it has been said that the window interface is not very good and that it is not easy to convert .P to .WAV files.
Sorry, but I have to disagree - once I have used it a couple of times, it's actually very easy to use.
From the File Menu, Select "New+Add". Select the ".P" file, click OK on the next box then click "Play" - that's all you need to do to play a ".P" file into the soundcard. So, just a few clicks needed to get the .P file to the ZX81.
Alternatively, just click "SBB => WAV" to convert it quickly to a WAV.


There's even a "batch" option to convert .P to .SBB then .SBB to .WAV


...I'll publish the tape input cleaner circuit that I knocked-up shortly if anyone is interested.


Regards.


Grant.

Re: O.T.L.A. (high speed loader) works for me too !

Posted: Wed Sep 07, 2011 7:48 am
by Paul
zx80nut wrote:...I'll publish the tape input cleaner circuit that I knocked-up shortly if anyone is interested.
Regards.
Grant.
Thanks a lot. Yes, we are definitely interested :!:

Will it be neccessary to have different settings for different speeds?

Regards.
Paul

Re: O.T.L.A. (high speed loader) works for me too !

Posted: Wed Sep 07, 2011 7:52 am
by sirmorris
This sounds great!*

I may be tempted to try a tape now and again...


*pun courtesy of Chuddleight & Chuddliegh, master punners to royalty 1887-1937

Re: O.T.L.A. (high speed loader) works for me too !

Posted: Wed Sep 07, 2011 7:55 am
by Andy Rea
Me too, i did play with it a little but since i have ZXpand the motivation for building an audio conditioner wasn't really there for me, mostly because my analog design skills are pretty poor :oops:

Thanks in advance

Andy

Re: O.T.L.A. (high speed loader) works for me too !

Posted: Fri Feb 14, 2020 8:03 pm
by diskman
I know Im replying to a 9 year old thread... Any chance you have the circuit for your hardware amp?? lol. Wishing..

Re: O.T.L.A. (high speed loader) works for me too !

Posted: Wed Apr 01, 2020 12:48 am
by marste
diskman interested in turbo tape
:D