VIC-MIDI - where is it headed?

[ral-clan]

Hi,

Did anyone else buy a VIC-MIDI cartridge? It does not seem to have been developed for (i.e. no support software other than what came out initially and was very basic). The documentation is so sparse I'm not even sure how to use mine. I would even consider trying to program it, but I cannot find much instructive documentation?

I heard there was a design fault in the original run, and Jim Brain was supposed to get in touch with us about fixing this. I did not hear from him.

Maybe we can make this thread a sort of gathering place for that type of info - and then I'll put it into a Denail WIKI article?

Hope to talk to VIC-MIDI owners and developers.

VIC-MIDI links:
http://www.go4retro.com/products/vicmidi/
http://store.go4retro.com/vic-20-midi-cartridge/
https://www.youtube.com/watch?v=p8VkudXFpiw
https://www.slideshare.net/leifbloomqui ... odore-2015
http://templarseries.atspace.com/maplin.html

[R'zo]

I have one. I plan on writing some programs for it myself eventually. I have other projects I'd like to accomplish first.

There is software that supports input but it is very simple. I've been able to play it with external keyboard and sequencers but it's buggy.

[ral-clan]

I did that too - play it with an external keyboard.
What I'd like to do is be able to do some basic MIDI receive / transmit stuff in BASIC. I know BASIC isn't really fast enough to do anything complex for MIDI, but I'm not a super great programmer, still learning (even though I've used a VIC for 40 years).

Problem is, the documentation that exists gives me no clue how to communicate with the VIC-MIDI, i.e. POKES, PEEKS, etc.

[Noizer]

Yes it‘s something similar flexible than an user port DAC.
Unfortunatly I lost my MIDI Interface time ago, it was running very well with Prophet image on big breadbox 64

[R'zo]

I did that too - play it with an external keyboard.
What I'd like to do is be able to do some basic MIDI receive / transmit stuff in BASIC. I know BASIC isn't really fast enough to do anything complex for MIDI, but I'm not a super great programmer, still learning (even though I've used a VIC for 40 years).

Problem is, the documentation that exists gives me no clue how to communicate with the VIC-MIDI, i.e. POKES, PEEKS, etc.

On the receiving in basic is fast enough for handling monophonic input. My musical keyboard program micro vicious runs in basic. It grabs user input from the keypress registor(bypassing the keyboard buffer is vital for speed) uses input value to index a note table and pokes [voice],[note table]+index. The reactivity is instantaneous. In theory all that would need to be done to index the note table from the midi input registors instead of keyboard input.

As far as output, the same could be done in reverse in basic as long as you only wanted realtime non synced instrument control. Syncing it to play with external controlled composition would be difficult I imagine (I know how to use midi but am still trying to understand how it works so I can't say for certain)

Brain has more info up on another forum about the registors. I'll try to find it later.

[R'zo]

You can download micro vicious here. The zip should contain the source code.
Micro Vicious 2.0

Edit: and the forum. jamming signal

[brain]

I'm always here to answer questions.

The only fault I'm aware of is that the two switches don't have pull up resistors. Not always a problem, but can be added if needed. Almost all units have the resistors installed, but a few got out before I noticed.

I designed the cart for Leif and friends, and it has the UltiMEM support, but I (maybe erroneously) assumed that if I got the hardware out in the marketplace, software would appear for it.

I considered porting the EF3 code to the VIC, but it's written in C, and cc65 wasn't playing nice with cart image creation until recently.

I am happy to provide all the tech details needed.

Jim

[brain]

The bulk of the unit is the 16c450 UART, which is described here: http://web.mit.edu/6.115/www/document/16c450.pdf
The unit operates at 18.432MHz, so it can handle MIDI and RS232 rates up to 230K and beyond.
The registers, by default are at IO3 (depending on the setting of S1, which is not normally installed)
Also by default, the UART sits at the top of IO3, but can be moved via the S6 jumpers. Normally, it sits at IO3:1111111XXX
To use the MIDI device, set the OUT1 flag in the 16C450 to be 1 (meaning the output will be low). RS232 = OUT1 = 0 (!OUT1 = 1) (OUT1 is register 2, bit 4)