There are currently some ZONX-81 compatible sound boards for the ZX81 under development:
in Germany:
http://forum.tlienhard.com/phpBB3/viewt ... ?f=2&t=464
in England:
http://www.rwapservices.co.uk/ZX80_ZX81 ... -t528.html
Would it be possible and make sense to support this sound boards in Z88DK?
The German board will also have the option to add a speech processor board, using a "SP0256-AL2" speech chip (same as in the Spectrum Currah Speech box used).
Is it possible to support that chip at the ZX81 by porting the Spectrum sources? Or is some additional soft/hardware within the Spectrum or Currah box used by Z88DK, which is not available for a ZX81?
Siggi
Sound and speech support for ZX81?
The sound support in z88dk is 1 bit beeper only and not AY unfortunately.
In terms of Currah speech support it looks like there's two ways of driving it: Setting the s$ string which is then picked up by the Currah ROM. The other way is loading the allophone string into memory at an address that's monitored by the ROM - section 6 of ftp://ftp.worldofspectrum.org/pub/sincl ... Manual.txt
In terms of Currah speech support it looks like there's two ways of driving it: Setting the s$ string which is then picked up by the Currah ROM. The other way is loading the allophone string into memory at an address that's monitored by the ROM - section 6 of ftp://ftp.worldofspectrum.org/pub/sincl ... Manual.txt
Yes, there is a nice trick to play one-bit sound by making the video flicker, but then you won't see the picture when the music plays !
I'd rather say it is possible to port some of the MSX or SEGA SMS libraries which are based on the Yamaha chip.
I never did it because they are both very basic functions, but.. well let's have a look
I'd rather say it is possible to port some of the MSX or SEGA SMS libraries which are based on the Yamaha chip.
I never did it because they are both very basic functions, but.. well let's have a look
Meanwhile there are some nice PT3- or STC-players available for the ZX81:stefano wrote:Yes, there is a nice trick to play one-bit sound by making the video flicker, but then you won't see the picture when the music plays !
http://www.youtube.com/watch?v=bnNnzJ_HuDs
http://www.youtube.com/watch?v=Tizsym426II
The Zeddy is running in SLOW mode (display active) and the player is hooked into the display routine ...
Siggi
It is not difficult to make an external hardware play correctly without impact on the screen, but I see no way to do it toggling the *same* bit used for both the video beam and the tape output !
Well, I just committed my attempt to extend the 1-bit sound library to the zx81, the examples in {z88dk}/examples/sound should be runnable in any startup mode (those video flag bits we talked about recently are very cool).
I'd be glad for know how this code behaves on the real hardware.. what happens if you just raise the TV volume ?
Another idea could be to obtain an audio squelch combining an external amp with that "turbo mode led" circuit I saw somewhere on the web and get rid of the TV noise when sound is not playing
Well, I just committed my attempt to extend the 1-bit sound library to the zx81, the examples in {z88dk}/examples/sound should be runnable in any startup mode (those video flag bits we talked about recently are very cool).
I'd be glad for know how this code behaves on the real hardware.. what happens if you just raise the TV volume ?
Another idea could be to obtain an audio squelch combining an external amp with that "turbo mode led" circuit I saw somewhere on the web and get rid of the TV noise when sound is not playing
Being fashionably late...
The currah on the spectrum is horrible Well, from a m/c (and therefore C) programmer's point of view. Its operation is closely tied to basic and involves passing phonemes using basic string variables. The special library is there to deal with all that craziness.
There is no AY support within z88dk. Currently music is composed using 3rd party trackers (see eg VortexTracker for Windows) whose output is an interrupt routine that plays the music. You would then arrange to call the routine at a 1/50s rate usually by installing it on an interrupt. On the spectrum this is done with the IM2 library.siggi wrote:Would it be possible and make sense to support this sound boards in Z88DK?
I think the right way to do it would be to have it appear as a device that can be attached at the end of a file stream. Then you could printf phonemes to it.The German board will also have the option to add a speech processor board, using a "SP0256-AL2" speech chip (same as in the Spectrum Currah Speech box used).
Is it possible to support that chip at the ZX81 by porting the Spectrum sources? Or is some additional soft/hardware within the Spectrum or Currah box used by Z88DK, which is not available for a ZX81?
The currah on the spectrum is horrible Well, from a m/c (and therefore C) programmer's point of view. Its operation is closely tied to basic and involves passing phonemes using basic string variables. The special library is there to deal with all that craziness.