About AY

Who knows: AY registers are readable on all Spectrum-compatible ones,
or are there exceptions? Ali are not available at all?

Interested in applying effects over music. It looks like this: if
an effect is played, in the handler after playing the next melody note
save the values ​​of the AY registers, play the effect note in the desired channel (for example,
C, so that the melody remains in A and B). Upon arrival next. interrupt restore
registers AY. And again... until the effect is lost.

Maybe all this is done easier - this is the first time I’m doing this :)

Warm greetings, Slava!

VM> Who knows: AY registers are readable on all
VM> Spectrum-compatible ones, are there exceptions? Ali are not available at all?

There are left-handed schemes (not many people have left) that crap the bus in them and don’t work
reading registers. You don't need to pay attention to these ones, but the rest of the registers are readable. I've seen such a board only four times.

VM> Interested in applying effects over music. It is represented by
VM> like this: if an effect is played, in the handler after playing the next
VM> melody note, save the values ​​of the AY registers, play the effect note in the
VM> desired channel (for example, C, so that the melody remains in A and B). Upon arrival
VM> next. interrupts restore AY registers. And again... until the effect
VM> is played back.

What if the effect is put into one channel without touching the others?

VM> Maybe all this can be done easier - this is the first time I’m doing this :)

I’ve never done it myself.

With respect, Alex from FFC COMPUTERS.

Available, but not for everyone. For example, my friend had a computer, so he received #FF bytes from the AY registers. But there are very few such perversions. Usually
registers can be read.
This is done like this: you set the register via port #FFFD, and then
from it you read the state of the corresponding register.

With respect, Roman.

VM>> available?
RP> Available, but not at all. For example, my friend had a computer, so he
RP> received #FF bytes from the AY registers. But there are very few such perversions.
RP> Usually registers can be counted. This is done like this: you install a
RP> register via port #FFFD, and then read the
RP> state of the corresponding register from it.
However, there are exceptions. If the wiring diagram is assembled incorrectly,
then the music processor will not work properly. or it may work, but not be readable, and even if it is accessible, it may not be readable. For example, I went through about five circuits until I found one that was 100% compatible with all software, and still I had to
tweak it a little in terms of circuit design...

Oleg AKA Olav

... Any stink that fights the fan tends to consider itself Don Quixote.

/skip/

VM>> next arrival. interrupts restore AY registers. And again ...
VM>> until the effect is lost.
DG> You need to restore it once and only at the very end.

In this particular case, the problem was solved as follows. To
play the melody, a tracker is used. To play
each note, his player _always_ sends to AY the values ​​of almost all registers (at least from
0 to 12), i.e. it turned out to be unnecessary to memorize register values ​​for subsequent restoration. The only important value is the contents of the control register (7), but the player stores this in memory. Knowing the contents of the 7th
register is necessary to avoid accidentally allowing a note/noise to play on
any channel where it is prohibited.

VM> According to Chris & RML, registers are readable in barely
VM> 20% of computers :( I have to dance from this statement :(( What
VM> to say if this feature does not work on all emulators :))

In 5020 the situation is better, so Recently there have been boards on sale
that allow you to read registers. At the moment, Zelenograd Pentagons
also have a correct circuit, so the number is the opposite of 20% of the left circuits. And emulators
are not an indicator of correct circuit design, since writers
only recently learned about it.

Saturday September 20 1997 18:40, Alex Letaev wrote to Vyacheslav Mednonogov:

AL> What if the effect is in one channel without touching the others?

Some of our people have worked out this method for a long time, imho.

C u l8r,
Dmitry aka ZDW.