Printer port programming

[Dbug]

Hi,

does anyone here has code that allows to send characters to the printer, without relying on the ROM?

I'd like to add the possibility to write log datas on the printer (can be practical to track bugs, profile code, etc...) but I have no idea on how to do that without using LPRINT...

Thanks in advance

[Dbug]

Ok, Twilighte suggested copying the Rom routine, and it's actually short, so here it is for everybody's benefit:

Code: Select all

; A=character to send
_PrinterSendChar
.(
 php
 sei
 sta $301		; Send A to port A of 6522
 lda $300
 and #$ef		; Set the strobe line low
 sta $300
 lda $300
 ora #$10		; Set the strobe line high
 sta $300
 plp
loop_wait 		; Wait in a loop until active transition of CA1
 lda $30d
 and #2
 beq loop_wait	; acknowledging the byte
 lda $30d
 rts
 .)

To use it, just put the value in the accumulator and call the routine.

[highwayman]

i wrote a program once that could do a hires screendump to the printer by pressing the warmstart button.

was real good at taking snaps of xenon-1 etc.

i'll have to try & ocr it or maybe even re-type it!