On Tue, Sep 06, 2016, Eric Christopherson wrote:
> On Tue, Sep 06, 2016, Cameron Kaiser wrote:
> > > Interesting. I've been trying to get a WiFi device for the Commodore
> > > 8-bits working consistently in 9600 bps mode, and have just been
> > > assuming the garbage characters I get when I receive a screenful of text
> > > all at once were due to buffer overruns. The garbage characters there
> > > look like actual garbage, not like partial CSIs like [3;1m or whatever.
> >
> > Unless you're using an ACIA cartridge, 9600bps on the C128 is problematic,
> > and impossible on the C64.
>
> Not quite; someone named Daniel Dallmann found a way to do it on the
> user port, on both 64 and 128 (in the 1990s, I think). It's commonly
> called "UP9600". I've only found one terminal program* so far that
> actually performs well and doesn't drop characters or bring up garbage
> ones, on the device I mentioned (I have never tried it with a proper
> modem).
>
> I'm not sure what's different about the CIAs in the 64 and 128
I see a few mentions online about the 128 supporting 9600 natively, but
no real details. Do you have any to share?
I wonder if it'd be worth turning off the device's UP9600 support and
seeing if the 128 will still talk 9600 to it. (If I do keep it on,
apparently the 128 will be able to do 19200 -- but I'm not holding my
breath, based on my experience with 9600.)
> but, in
> the case of this specific hack, it's theoretically easier to deal with a
> 64 -- or at least a 128 with no 1571 or 1581 -- because the 9600bps hack
> clobbers the SRQ line that those drives use for fast serial operations.
> (Things still work if you turn them to slow mode, as happens when you
> boot directly into 64 mode.) But I find that I never get it to work
> non-problematically except when I use that one terminal emulator using
> the C128's VDC for display. I'm not sure how much the 40-column mode's
> 1MHz clock contributes, and how much VIC emulated 80-column mode and the
> VIC's scrolling speed, contribute to the problem. (Will have to try it
> with true 40-column mode, but then the actual viewport will fill with
> characters and need a scroll twice as fast.)
>
> * The terminal emulator I've had success with is NovaTerm 9.6.
>
> >
> > If you *are* using an ACIA cartridge, then 9600bps is well within spec and
> > should "just work." I'd look at your driver instead. A buffer overrun
> > should just drop characters, not munge them.
>
> I wish I could get more than one-sentence responses from the developer
> of the device. Hopefully he'll fix it in the future, if I can make a
> good case for it.
--
Eric Christopherson
