********************************************************************
* scdwp.asm - CoCo DriveWire Printer Driver
*
* $Id$
*
* Edt/Rev  YYYY/MM/DD  Modified by
* Comment
* ------------------------------------------------------------------
*  1       2009/03/06  Boisy G. Pitre
* Started.

         nam   scdwp
         ttl   CoCo DriveWire Printer Driver

         ifp1
         use   defsfile
         use   drivewire.d
         endc

tylg     set   Drivr+Objct   
atrv     set   ReEnt+Rev
rev      set   $00
edition  set   1

         mod   eom,name,tylg,atrv,Start,Size

         fcb   READ.+WRITE.

name     fcs   /scdwp/
         fcb   edition    one more revision level than the stock printer

* Device memory area: offset from U
         org   V.SCF      V.SCF: free memory for driver to use
V.PAR    rmb   1          1=space, 2=mark parity
V.BIT    rmb   1          0=7, 1=8 bits
V.STP    rmb   1          0=1 stop bit, 1=2 stop bits
V.COM    rmb   2          Com Status baud/parity (=Y from SS.Comst Set/GetStt
V.COL    rmb   1          columns
V.ROW    rmb   1          rows
V.WAIT   rmb   2          wait count for baud rate?
V.TRY    rmb   2          number of re-tries if printer is busy
V.RTRY   rmb   1          low nibble of parity=high byte of number of retries
V.BUFF   rmb   $80        room for 128 blocked processes
size     equ   .

start    equ   *
         lbra  Init
         lbra  Read
         lbra  Write
         lbra  GetStt
         lbra  SetStt

* Term
*
* Entry:
*    U  = address of device memory area
*
* Exit:
*    CC = carry set on error
*    B  = error code   
*
Term     equ   *
         clrb
         rts

* Init
*
* Entry:
*    Y  = address of device descriptor
*    U  = address of device memory area
*
* Exit:
*    CC = carry set on error
*    B  = error code
*
Init
* Check if D.DWSubAddr already holds a valid subroutine module pointer
         IFGT  Level-1
         ldx   <D.DWSubAddr
         ELSE
         ldx   >D.DWSubAddr
         ENDC
         bne   InitEx

* If here, D.DWSubAddr is 0, so we must link to subroutine module
         IFGT  Level-1
         ldx   <D.Proc
         pshs  x
         ldx   <D.SysPrc
         stx   <D.Proc
         ENDC
         clra
         leax  dwioname,pcr
         os9   F$Link
         IFGT  Level-1
         puls  x
         stx   <D.Proc
         ENDC
         bcs   InitEx
         IFGT  Level-1
         sty   <D.DWSubAddr
         ELSE
         sty   >D.DWSubAddr
         ENDC
         jsr   ,y			call init routine
InitEx   rts

dwioname fcs  /dwio/

* Write
*
* Entry:
*    A  = character to write
*    Y  = address of path descriptor
*    U  = address of device memory area
*
* Exit:
*    CC = carry set on error
*    B  = error code
*
Write    equ   *
         tfr   a,b
         lda   #OP_PRINT
         pshs  d
         leax  ,s
         ldy   #$0002
         IFGT  Level-1
         ldu   <D.DWSubAddr
         ELSE
         ldu   >D.DWSubAddr
         ENDC
         jsr   6,u
         puls  d,pc


* GetStat
*
* Entry:
*    A  = function code
*    Y  = address of path descriptor
*    U  = address of device memory area
*
* Exit:
*    CC = carry set on error
*    B  = error code 
*
GetStt   cmpa  #SS.EOF		end of file?
         bne   L0112
         clrb			if so, exit with no error
         rts   

L0112    ldx   PD.RGS,y
         cmpa  #SS.ScSiz
         beq   L0123
         cmpa  #SS.ComSt
         bne   L0173
         clra
         clrb
         std   R$Y,x
         clrb
         rts

* get screen size GetStt
L0123    clra  
         ldb   #80
         std   R$X,x
         ldb   #24
         std   R$Y,x
         clrb
         rts

* SetStat
*
* Entry:
*    A  = function code
*    Y  = address of path descriptor
*    U  = address of device memory area
*
* Exit:
*    CC = carry set on error
*    B  = error code 
*
SetStt   
Close    cmpa  #SS.Close	close the device?
         bne   L0173
         lda   #OP_PRINTFLUSH	send PrintQueue Flush Packet
         pshs  a
         ldy   #$0001
         leax  ,s
         IFGT  Level-1
         ldu   <D.DWSubAddr
         ELSE
         ldu   >D.DWSubAddr
         ENDC
         jsr   6,u
         puls  a,pc

Read     comb  
         ldb   #E$BMode
         rts

L0173    comb
         ldb   #E$UnkSVc
         rts

         emod
eom      equ   *
         end