VIC MIDI Cartridge

brain · Post by **brain** » Thu Jun 20, 2013 12:20 am

Unit is far enough along that I can share. Comments on schematic are appreciated. I have tested the previous version of this design (with a '173 instead of the '273) for operation and banking and all looks OK. This one adds a '273 instead to use an active low reset line, and allow ROM to be turned off.

http://jbrain.com/vicug/gallery/vicmidi ... tic?full=1

Schema · Post by **Schema** » Sat Jun 22, 2013 3:17 am

- MIDI THRU isn't labelled. Will it be populated by default?
- We had talked about activity LEDs on the ports, is that reasonable (complication/cost)?
- Can a reset button be added? (I recall this question for the 64NIC+

)

brain · Post by **brain** » Sun Jun 23, 2013 7:07 pm

They will all be labelled and installed.
No, but IN and THRU would support only 1 LED, as there is not difference. Color choices?

I'll put a RESET on it, just to keep the questions at bay.

JIm

brain · Post by **brain** » Wed Jun 26, 2013 12:15 am

Success! The Clavinova CVP407 likes the new code drop. I didn't see any misses until I started paying with the MIDI channels on the KB while it was playing a pre-recorded song, and I don't think that counts.

If there's a way to get a channel where all of the voices come on at the respective notes, I'll have my wife play a song with the unit and record it.

Jim

Schema · Post by **Schema** » Wed Jun 26, 2013 9:26 pm

As discussed by email, that's the plan. You should still be able to get 3 octaves out of any given voice though?

brain · Post by **brain** » Sun Jul 21, 2013 3:12 pm

Final design. Features:

16450 based UART, can be replaced with 16550 if desired
Up to 512kB of FLASH ROM mapped to BLK5 (64 banks), probably will ship with 128kB (16 banks).
Can be reprogrammed from the VIC
requires just 16 IO locations in IO memory map.
Bank register sits at base+15
IO2/IO3 selectable
MIDI IN,OUT,THRU
IN/OUT Activity LEDs
RESET button
RS232 drivers and DB9 onboard for RS232 cart usage
Can be selected to hook MIDI IN to MIDI OUT if desired
/IRQ support
FLASH ROM disable
FLASH need not be installed
RS232 need not be installed
MIDI need not be installed (if used as RS232 only)
RS232 TxD and RxD can be set to connect to each other
Switching from RS232 to MIDI use can be done via SW, no switches or parts replacement needed.

Now, I really need to get my BLK5 cc65 template working, as I need to write a menu for bank 0, Leif's app in bank1, and a terminal emulator in bank2.

Jim