Mark Geary

In article <dog_cow-1327970435@macgui.com>,
D Finnigan <dog_cow@macgui.com> wrote:
> I checked three different news servers, and both of ict@ccess's most recent
> posts two this thread did not arrive. Nor did the article appear to have
> been canceled with a cmsg.
>
> Message-ID:
> <35e3e186-cc80-4979-bb36-f25091c85153@iu7g2000pbc.googlegroups.com>
> Message-ID:
> <4d5dc749-2ade-4083-bbe1-f8fd22f02838@b10g2000pbd.googlegroups.com>
>
> Anyone else get these (or not) at their site?

I see them on astraweb.
--
Don't forget to stop and eat the roses.

Michael Black

On Mon, 30 Jan 2012, Steve Nickolas wrote:

> On Mon, 30 Jan 2012, Sean Fahey wrote:
>
>> On Monday, January 30, 2012 1:45:30 PM UTC-6, Steve Nickolas wrote:
>>
>>> Fortunately, a simple beep's all I need.
>>
>> Beep.
>>
>
> LOL.
>
> Actually, I'd been thinking of how I could design a "neovintage" computer,
> and put concepts of various computers into a blender. I figured for a CPU
> I'd use a 65C02, for video 6847, for audio AY-8910. As far as sound goes
> that meant the hardware would basically be a Mockingboard mapped to a
> different address. >:P
>
Get the synthesizer IC used in the IIGS, that's so much fancier than the
8910.

That sound generator was designed for games. It has limitations, not in
terms of the frequencies it can generate (since frequency is controlled
by a string of programmable dividers, one can get just about any
frequency) but the waveform is limited, as is some of the control
functions. But it certainly offloaded a lot of stuff at a time when the
CPUs were quite limited.

Right about the same time, there were plenty of articles about using the
6502 (and other CPUs) for generating sounds or even music, but they tended
to be about standalone work. So you could do music synthesis with a 6502,
but it would get in the way if all you wanted was a Beep while you did
other things with the 6502. Hal Chamerlin's book about using
microprocessors for electronic music details it well.

This late in the game, one might as well add a second 6502, and whatever
hardware like a DAC is needed. Much of the RAM can be used for the
sounds/music (and that RAM is so much easier when you can put the full 64K
in a single IC), and then figure out how to control it from the main 6502.
So instead of generating tones, and then waveshaping, you can generate a
more exotic waveform at the desired frequency, and so on.

I seem to recall there was some add on for the Apple II that went this
way, rather than adding something like the 8910.

Michael

> I prolly won't be able to design a physical version but I've been trying to
> design it practically, as in, would this work if the machine were really
> built with the tech of the time?
>
> Conceptually, though, I could in fact implement it in *software* - just like
> one would implement an emulator. And if I needed to learn anything in the
> process, I could rewrite Dapple with the new knowledge too.
>
> Implementing a system beep via the Mockingboard sounds impractical, but
> against the masterplan it was what I wanted to do.
>
> (BTW, a Fine tone of "69" is closest, afaict, to the system bell. I think 80
> sounds better though. And if I could somehow make a "dink" instead of a
> simple beep that would be nice too.)
>
> -uso.
>

Michael Black

On Mon, 30 Jan 2012, BLuRry wrote:

> The mockingboard sample disk has some SFX routines that can be easily
> modified for this -- I spent some effort trying to write an IRQ-based
> playback routine but fell short of getting the darn thing to work
> correctly!
>
> Tom Charlesworth actually pulled off a great conversion of a Speccy
> chiptune to playback on the mockingboard. (Cybernoid)
>
> http://www.tomcharlesworth.pwp.bluey.../Cybernoid.dsk
>
> Anyway, I remember one thing that kicked my butt: If you don't init the
> card properly, it will basically do nothing with you data. I think it's
> more of a 6522 thing than it is an AY thing though, if my hazy memory is
> working at all.
>

I wouldn't remember either.

But the 6522 did need initializing.

And the 8910 was generally hooked up so you controlled its address pins
with a parallel port, so you had to address the right register in the 8910
before you could send it data.

But it was simple, since for just a single tone, you could just leave it.
If anything, you didnt' want that, so you had to do something to turn off
the tone before it drove you nuts.

Michael

Steve Nickolas

On Tue, 31 Jan 2012, Michael Black wrote:

> On Mon, 30 Jan 2012, Steve Nickolas wrote:
>
>> Actually, I'd been thinking of how I could design a "neovintage" computer,
>> and put concepts of various computers into a blender. I figured for a CPU
>> I'd use a 65C02, for video 6847, for audio AY-8910. As far as sound goes
>> that meant the hardware would basically be a Mockingboard mapped to a
>> different address. >:P
>>
> Get the synthesizer IC used in the IIGS, that's so much fancier than the
> 8910.

And rarer. Only a few keyboards and the GS used it. The AY was used on
the MSX, Atari ST (in a variant) and some versions of the Spectrum, plus
other systems - it got around.

Heck - the video chip I was plugging into the virtual machine was, more or
less, the one used in the Tandy Color Computer, the Laser 210, the Acorn
Atom, and a couple oddball machines from Brazil.

As for the BASIC? It's not actual 80s code but it's the same basic (lol)
dialect seen on pretty much every home computer apart from Acorn's and
Atari's offerings.

-uso.

Michael J. Mahon

if you want a beep that fades--a bonk--that's easy too. Just set the ADSR
mode and the decay rate and you're done. You will need to be in
"single-shot" mode or you'll get repeated bonks.

-michael - NadaNet 3.1 and AppleCrate II: http://home.comcast.net/~mjmahon

Linards Ticmanis

On 01/31/2012 08:14 PM, Mark Geary wrote:

>> Message-ID:
>> <35e3e186-cc80-4979-bb36-f25091c85153@iu7g2000pbc.googlegroups.com>
>> Message-ID:
>> <4d5dc749-2ade-4083-bbe1-f8fd22f02838@b10g2000pbd.googlegroups.com>
>>
>> Anyone else get these (or not) at their site?
>
> I see them on astraweb.

They're there just fine on news.arcor.de too.

--
Linards Ticmanis