newbie questions

Anything Sinclair ZX Basic related; history, development, tips - differences between BASIC on the ZX80 and ZX81
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yerzmyey
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Re: newbie questions

Post by yerzmyey »

SirMorris:
Hi,
I actually read the forum but the problem is, some new "safety" scripts block me most of the time. :(


> Does it need extra hardware or will the sound come from the ear socket??
-------------
I thought Utz used the beeper routines but it seems like he used the engine "playing" on the TV.

I'm still surprised I can't hear _anything_ from my ZX81 computers from the MIC, even when I type
SAVE "jasio" or whatever. Still nobody can explain me why there is almost no sound, probably people here abandon tapes years ago (ZX96, ZX2000 and all the CF/SD cards).



Utz:
> as far as i understand the best way would be to record sound from a (real) TV, as the routine uses the VSYNC signal to make the music.
----------------
Aha. This I can't record, obviously. ;) Hmmm. Or - rather not.
Still, without a P file I can't tell.
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/
angus
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Re: newbie questions

Post by angus »

I'm still using occasionally using tapes. You should have signals from the 'mic' socket. Even when the computer is dormant there should be a low level hum. When you actually execute the SAVE command there should be anything from 20 seconds to 8 minutes of mid frequency activity. You might pick it up with headphones, though the output is not designed for them. You should certainly pick it up with an amplifier or when recording to tape.

If not then there are a few possibilities. Your Zeddy could have an issue with the SAVE routine - what does the TV screen look like when saving? There should be more or less horizontal black/white bars moving jaggedly on the screen during the SAVE and LOAD routines.

It could simply be that the ZX81 or cassette recorder's socket has become disconnected internally. Or that your cable is broken. Also be sure to use a mono cable and not stereo. If you must use a stereo cable then obtain mono jack adaptors.

HTH
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yerzmyey
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Re: newbie questions

Post by yerzmyey »

angus wrote:I'm still using occasionally using tapes. You should have signals from the 'mic' socket. Even when the computer is dormant there should be a low level hum. When you actually execute the SAVE command there should be anything from 20 seconds to 8 minutes of mid frequency activity. You might pick it up with headphones, though the output is not designed for them. You should certainly pick it up with an amplifier or when recording to tape.
If not then there are a few possibilities. Your Zeddy could have an issue with the SAVE routine - what does the TV screen look like when saving? There should be more or less horizontal black/white bars moving jaggedly on the screen during the SAVE and LOAD routines.
It could simply be that the ZX81 or cassette recorder's socket has become disconnected internally. Or that your cable is broken. Also be sure to use a mono cable and not stereo. If you must use a stereo cable then obtain mono jack adaptors.
HTH

Thanx a lot, that's what I will do.
Like I wrote before, I have a mixer now, so finally I have a _real_ mono IN. That's what I will use (plus some beeper ZX81 demos) for further tests.
Thx again. :)
Y
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/
utz
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Re: newbie questions

Post by utz »

Ok, since nobody seems to have an idea how to make the scroller fit, i'm releasing this as is, without any personalized greetings.

I have no idea how well it works on real hardware, if someone tries it out please let me know.

Anyway thanks for taking the time to answer my n00b questions and hope you enjoy. Also special thanks to Kelly Murta for the music routine.
yerzmyey wrote: I thought Utz used the beeper routines but it seems like he used the engine "playing" on the TV.
As far as I understand nearly all ZX81 sound routines output sound via VSYNC. You should still be able to hear something on MIC port, because after all it's ULA which generates the sound, but the signal will probably be very low. Anyway Yerz I think it's not necessary to record this demo, it's not that great, only one short song. Also I didn't include the multichannel thing - it's possible to do it, but it eats way to much memory. I would have been able to fit maybe 10 seconds of music maximum. Also to make something decent-sounding I'd need to modify the routine, and although I'm starting to learn some ASM I don't yet have enough knowledge to do that.

edit: Did you see this?
yerzmyey wrote: I'm still surprised I can't hear _anything_ from my ZX81 computers from the MIC, even when I type
SAVE "jasio" or whatever. Still nobody can explain me why there is almost no sound, probably people here abandon tapes years ago (ZX96, ZX2000 and all the CF/SD cards).
I've read that unlike on Speccy, ZX81 has some special circuitry that lowers the volume output, so it's probably normal that there's a very low output when saving to tape.
Attachments
utztap81.p
Utztape81 VSYNC music demo for ZX81+16k
(7.45 KiB) Downloaded 244 times
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yerzmyey
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Re: newbie questions

Post by yerzmyey »

OK then.
Thx for Your effort in ZX81 world, we do appreciate it.
You should advertise the new prog in Developement section. ;)
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/
angus
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Re: newbie questions

Post by angus »

utz wrote:
I've read that unlike on Speccy, ZX81 has some special circuitry that lowers the volume output, so it's probably normal that there's a very low output when saving to tape.
I don't know if the Speccy lacks any volume circuitry, but the signal from the ZX81 is definitely lower. I remember "back in the day" hooking up the Speccy to a cassette recorder with manual record level and recording the signal at 0dB. Then hooked up the Zeddy and the signal was a lot lower, probably in the region of -10dB but I don't remember for sure.

It's OK with most auto level cassette recorders as they'll simply adjust. And note that as soon as you press NEWLINE and initiate a SAVE command the hum from the mic output gives way to near silence for a couple of seconds before the program is saved.

However it does mean that with headphones you may hear little or nothing. And with auto level cassette recorders which are not good with low inputs it might cause issues.
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yerzmyey
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Re: newbie questions

Post by yerzmyey »

Only yesterday I was able to listen to the song and it's incredibly good as for one channel only!
Even on emulator.
I wonder why it is audiable on the emul only when I enter the "BEEPER Sound" option. It would suggest - it's still a beeper anyway. Hmmmmmmmmmmm.......
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/
utz
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Re: newbie questions

Post by utz »

thanks Yerzmyey. I'm glad you enjoyed it. Not sure if I should post this again in /Developement, I feel like I'm going on people's nerves here already with this thing.

Btw there seems to be a way to make (pseudo-)polyphonic sound on the Zeddy after all - will try it out once i've managed to install the latest Z88DK. If you have time take a look at the link i gave some posts above - check out "synthdemo.p", you will be surprised.
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yerzmyey
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Re: newbie questions

Post by yerzmyey »

utz wrote:thanks Yerzmyey. I'm glad you enjoyed it.
Haha, I was listenning to it from real hardware last times! :) (My ZXpand came to me from UK and it works great!).
It sounds really good. I connected it into amplifier in my mixer and used several knobs to make the sound louder. :)
I have no idea how You was able to make such a complicated song by coding only.

This isn't the same engine which is in "Beatles" demo? Yours seems to be far more stable.
Who knows, maybe I could be able to record it after all.
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
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Re: newbie questions

Post by sirmorris »

utz wrote:Not sure if I should post this again in /Developement, I feel like I'm going on people's nerves here already with this thing.
No! We love to hear about new techniques and try to help where we can. I think people simply don't have any useful stuff to tell you. Please don't think we don't want to know..!

C
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