hasbab wrote:there is a fairly extended discussion on gearslutz about midi latency and jitter with some info about the ST and dongles if that's of any use to any of you
That pretty much confirms my suspicions that Cubase and Notator have pretty lousy timing! There is definitely a need for a MIDI sequencer that takes full advantage of the ST.
In any case, regardless of how bad Cubase performs in reality my aim is to design the actual interface to perform to better than 0.032ms of jitter and latency. Then if better software is developed it can really be exploited.
MIDI input via the cartridge port will always have a jitter, that can never be avoided. But MIDI input via the printer port can actually be as tight as the CPU will allow. In theory a cartridge port device like Midex or Unitor can provide perfectly tight timing on output. But it seems existing software does a poor job of exploiting this.
Miguel wrote:When I noticed the two ports and DIP switches I thought they are either for daisy-chaining or configuring the MM1 for some other platform like the DIP switches on Steinberg's MIDI-3.
At this point I'm almost certain it's something to do with daisy chaining. The unit I've been looking at has the first DIP switch off and the next four on. The fifth DIP switch does something different. So I think turning off the first DIP switch might make the unit the first in the chain.
Sadly, the MM1 driver does not have any provision for supporting daisy chaining. It appears hard-coded to 8 ports. But the Starport driver obviously supports it.
I'm making progress with the disassembly. I might be able to modify it for 16/32 port support in the future. Obviously that's never going to happen with a real MM1 seeing how rare they are. But the clone would be easy to daisy chain then (subject to total cable length limitations!)
I have some hardware in mind already for the clone. Only about 6 ICs, so it will be easy to build. I could include two MIDI inputs in addition to the 8 outputs. But you'd need a special driver to use the inputs. And the inputs won't be compatible with daisy-chaining (you need to choose between using four devices for 32 outputs only, or one device for 2 in 8 out with a DIP switch). But I think that's a fair limitation?
Of course it might turn out that Cubase simply can't cope effectively with more than 8 MIDI ports anyway without severe lag. In which case I'll ditch the daisy chaining feature. It kind of amazes me that the Starport ever supported 32 MIDI outputs from a single ST. That's crazy!