On Sun, 2010-07-04 at 19:08 -0400, Gene Heskett wrote: > On Sunday 04 July 2010, Gordon JC Pearce wrote: > >On Sun, 2010-07-04 at 22:16 +0100, Dan Mills wrote: > >> You could probably hack a multi serial port card to do multiple midi > >> ports (Change the rock to give a suitable divider for 31250 baud > >> (4MHz?), add current loop interfaces)... > > > >Been there, done that - when I was a penniless dole-scrounging scruffy > >university drop-out living on a farm in the middle of nowhere, I decided > >I needed a MIDI sequencer. So, I modified an old serial card with a > >4MHz crystal which divides to 31250 baud, and wrote a simple > >tracker-style sequencer in a mixture of C and assembler on DOS. It > >worked, kind of. If you wanted to do anything really wild like change > >the tempo you needed to recompile. > > > >Gordon MM0YEQ > > > As for the serial card with a different crystal, BTDT, on a TRS-80 Color > Computer 3. Not only that, but the software, Ultimuse-III, written by Mike > Knudsen could handle the serial card and the bitbanger at the same time, so > I actually had 2 ports and drove two different midi keyboards each with > their own midi voice assignments. This on a machine with 60 ticks/second > IRQ's for a clock. And neither port had any extra added buffers, it Just > Worked(TM).
60 ticks/second IRQ's for clock is for the C64 too, the UART was connected to the bus, but a serial port. _______________________________________________ Linux-audio-dev mailing list [email protected] http://lists.linuxaudio.org/listinfo/linux-audio-dev
