 sttl Parallel Printer Control Structure
 pag

*
* Parallel Printer Device Structure
*

PPBUFSIZ equ (3*128)+10 Queue Buffer Size
PPLOC equ PPBUFSIZ-FIFO_SIZE-5 low water mark
PPHI  equ PPBUFSIZ-1
PPCOND equ $2e disable interrupts
PPCONE equ $2f enable interrupts

 org 0
ppopen rmb 1 device open flag
ppadr rmb 2 PIA base address (B Side)
ppcnt rmb 2 character counter
ppbusy rmb 1 busy flag (kludge!)
ppipt rmb 2 input q pointer
ppopt rmb 2 output q pointer
ppbuf rmb PPBUFSIZ print buffer
ppbnd equ * buffer end
*
PPSIZ equ *
