8800 music! a proposal for a collective project

General discussions related to the Altair 8800 Clone

8800 music! a proposal for a collective project

Postby gio74 » February 1st, 2015, 8:22 am

Dear folks,
we all know that it is not possible to play fool on the hill with the radio interferences, nor the altair has a sound chip, not to talk of sampling possibilities.
BUT, computers have been used as controllers, and score editors since the days of the PDP.

while I'm here waiting for my 8800 clone to be shipped, I had an idea and I wonder if any of you would be interested in helping me out with some code to create something new with our beloved altair.

I work as a sound designer and professional musician and I have more than a decade of experience in MaxMSP language,
yesterday I was thinking about the I/O for the terminal emulator and I had one of those Eureka! moments..

I figured out that it may be possible to get some data out of the altair into a MaxMSP patch (as well as Pure Data and Processing) by connecting the serial output of the altair (pin 3 and 7 I guess) to an arduino board, which has digital and analog inputs.

Let's imagine for a second that we could program a simple basic software that outputs some alphanumeric at a given time.
If I find a way to get those bytes into arduino, I think I can translate them into music controls into MaxMSP.

I'm not very experienced in electronics, but I guess that that this is possible.

So to start off I'd like to ask to Mike what is the output voltage of the serial port (pin 3, grounding with pin 7?)...
arduino inputs works within 6-12V. Also I need to figure out if the digital input of arduino could work.. arduino anyone here?

If this connection is possible then I could write a software in Max to use that data to make music. I can develop this for mac and pc, later maybe for linux with pure data.
I would need some help to write a software in basic (or anything else the 8800 can use), starting from a simple sequence of letters with some timing feature... like a sequences of "A" every x milliseconds. to start off. later random numbers could be implemented to create some sort of generative sequencing.
I think that basic could be the choice (i have my C64 experience of my youth, but I hardly can say that i really know the full potentials of basic).

If all this work, I would love to share the patch and instructions to transform your 8800 into a music sequencer.

Anybody interested?
gio74
 
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Re: 8800 music! a proposal for a collective project

Postby gio74 » February 1st, 2015, 11:29 am

ALTERNATIVE IDEA in ASSEMBLY
------

Let's forget for a moment interpreters and let's think straight in the panel..(or Turnkey for the sake of speed)
Looking at the kill the bit program I wondered : could we instead program from scratch the 8080 in assembly and turn the whole 8800 computer into a 8 step sequencer without the need of basic or CP/M? I guess yes!

a 8 step sequencer I have in mind would be like this:

like the kill the bit program we have a blinking light making a sequence of 8 steps at a speed X
each step could hold an 8 bit number. So each step is nothing else than a memory address.
By turning on a switch in the highest bits interface under the blinking led, the data of that step is sent to the serial port > digital in of arduino > OSC to maxMSP
Each step should be programmable during the run.

can this be done?
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Re: 8800 music! a proposal for a collective project

Postby AltairClone » February 1st, 2015, 3:18 pm

What some people did in the day was wire into the INTE LED, which a program could toggle using the EI and DI instructions, and generate different frequencies for playing musical notes. Maybe such an approach would be more period-accurate?

Mike
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Re: 8800 music! a proposal for a collective project

Postby gio74 » February 1st, 2015, 5:58 pm

Hi Mike,
since all the audio computation can be easily done in MaxMSP, and far more efficiently. we don't need to set frequencies
we just need to send an 8 bit number to the serial port whenever a step is ON (we have 8 steps of course every step can be any 8 bit number)
we first need a metronome, say 120 beats per minute (*2, since we calculate 1/8 note values and not 1/4 note values).
I'm thinking to an approach that opens the possibility of triggering audio samples inside a max patch on the mac/pc.
This way the 8800 could serve as a programming sequencer for...say, a drum machine.

I will post a more precise scheme of the sequencer, later tomorrow.
I can write down a flow chart and then we can think if this can be done (but I'm confident we can, for drum machines as an example, are very very simple softwares)..
for the sake of clarity if needed, I can program a simple simulation in max.

thanks much for the help!
can't wait to play with the glorious 8800 clone :)
Last edited by gio74 on February 2nd, 2015, 4:49 am, edited 1 time in total.
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Re: 8800 music! a proposal for a collective project

Postby gio74 » February 2nd, 2015, 4:36 am

this is the crude chart of the little sequencer. it's a starting point.
All the LEDs off course have off instructions after each step has been read.


Image
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Re: 8800 music! a proposal for a collective project

Postby gio74 » February 3rd, 2015, 9:24 am

Seems like that Max7 can read data from a serial port, so no arduino will be needed.
GREAT!
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Re: 8800 music! a proposal for a collective project

Postby gio74 » February 18th, 2015, 2:58 am

Altair says hello!

the first thing to do was to produce a steady tone at X frequency
and here it is!

https://vimeo.com/119930512
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Re: 8800 music! a proposal for a collective project

Postby AltairClone » February 18th, 2015, 11:49 am

Cool! Good progress and definitely using the Altair old-school style!

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Re: 8800 music! a proposal for a collective project

Postby gio74 » February 18th, 2015, 1:19 pm

Yeah!

I'm coding right now a new version.
This one will output 8 different bytes stored in some specific addresses.
it should be enough to create a drum machine with 8 channels :D


stay tuned!
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Re: 8800 music! a proposal for a collective project

Postby gio74 » February 20th, 2015, 11:07 am

the episode is online now :)
8 step sequencing shakes the dance floor


https://vimeo.com/120147663
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