SIO2BSD turbo speed

[Gunstar]

Can someone give me a link to this "Atariserver" you guys are referring too?

[HiassofT]

Can someone give me a link to this "Atariserver" you guys are referring too?

https://www.horus.com/~hias/atari/#atarisio

 

so long,

 

Hias

[RockfordDash]

OK, time for some more results. I hooked up RPi Zero W again and retested the speeds. In a *default* RPi configuration usable range for devider 1 is the same as it is in RPi 3+: 107000 to 111850.

Previous results of 108940 - 112120 were due to me messing up with UART clock. I left this line in /boot/config.txt: init_uart_clock=1920000. If I remove it, range of 107000 - 111850 is what I'm getting.

I also hooked up command line, and again, just like RPi3+ my RPi Zero W performs well with handshake. No need to specify baud rates, just a divider:

sudo ./tools/atariserver -f /dev/serial0 -C -S 0 -p -1 ../hisioboot-atarisio.atr -p -2 ../BRUCELEE.ATR

Hope this clarifies results.

[HiassofT]

So yes, rate ranges differ for some reason. I retested them to be sure and that's what they are on RPi 3. Let me connect command line to RPi Zero, add dtoverlay and see if it changes anything.

Could you double-check that you are using /dev/ttyAMA0 on RPi0W as well? With the miniuart /dev/ttyS0 speeds will be a bit different (IIRC 31.5MHz baud base but only integer dividers).

 

In general I try to avoid the /dev/serialX aliases and only use /dev/ttyAMA0 or /dev/ttyS0 to select devices, then it's clear which one I used for tests :-)

 

so long,

 

Hias

[RockfordDash]

Positive. I'm using serial0 which is configured to use AMA0:

pi@ataridrive:~/atarisio-190313 $ ls -l /dev/serial*lrwxrwxrwx 1 root root 7 Apr 10 09:38 /dev/serial0 -> ttyAMA0lrwxrwxrwx 1 root root 5 Apr 10 09:38 /dev/serial1 -> ttyS0

[HiassofT]

Thanks for checking!

 

Seems I missed your last post mentioning init_uart_clock. This'll result in a lower baud base (1.2MHz instead of 3) and also in higher jitter from the fractional divider. That's probably the reason for the changes in range.

 

so long,

 

Hias