P: device technical info?

[tschak909]

Is there a good reference on the P: device that's inside the OS ROM, and the various AUX1/AUX2 parameters etc? I am about to dig into the OS rom, but, I thought I'd ask here as well.

 

-Thom

 

[Chilly Willy]

The CIO chapters of the OS manual covers P: as it is in the rom.

 

[phaeron]

One apparent mistake in the OS manual's printer documentation -- Appendix K says that SIO write commands to the printer place the width control byte in AUX2, but the OS actually puts it in AUX1.

 

[jeffpiep]

Is there source for the 1027 handler? I’ve google around and cannot find it. I’m wondering how it adds 80 column support since the OS rom only has 20, 29 and 40 columns. At least that’s my naive read of it. thanks.

[tschak909]

from what I see, no matter what, you send data to it 40 chars at a time.

 

-Thom

[Chilly Willy]

The P: driver in the Percom receives 40 bytes at a time into ram, then goes through it looking for EOL. It substitutes CR for EOL, but otherwise just sends the data on to the printer.

 

[tschak909]

yup, that's my sense of it as well. we only need to do EOL/CR processing for TXT output. for PDF, we literally process the EOL directly.

 

Ironically, this makes the implementation very tiny on memory and processing requirements, doesn't take much to process a 40 char array (it can be done in a handful of machine cycles on the ESP)

 

-Thom