# HG changeset patch
# User boisy
# Date 1041803313 0
# Node ID bd7c8348adecf7df2e7f9aab25cbf34cb7e5ea64
# Parent  5ed7f616e80b939706155563900a57b1b3f860a3
This is the serial printer driver from NitrOS-9, backported to OS-9 Level Two
Note, the previous revision was actually the Disto printer driver.

diff -r 5ed7f616e80b -r bd7c8348adec level2/modules/printer.asm
--- a/level2/modules/printer.asm	Sun Jan 05 21:47:48 2003 +0000
+++ b/level2/modules/printer.asm	Sun Jan 05 21:48:33 2003 +0000
@@ -1,85 +1,347 @@
 ********************************************************************
-* Printer - CoCo 3 serial port printer driver
+* Printer - CoCo 3 Serial Printer Driver
 *
 * $Id$
 *
+* Enhanced and re-written by Alan DeKok
+*
+* Problems with original:
+*   returns wrong error on Read/SetStt
+*   doesn't block output.  The printer is a single-user device!
+*
 * Ed.    Comments                                       Who YY/MM/DD
 * ------------------------------------------------------------------
-* 12     Original OS-9 L2 Tandy distribution
+*        NitrOS-9 2.00 distribution                         ??/??/??
+*  13    Back-ported to OS-9 Level Two                  BGP 03/01/05
 
-         nam   PRINTER
-         ttl   CoCo 3 serial port printer driver
-
-* Disassembled 98/08/24 23:21:29 by Disasm v1.6 (C) 1988 by RML
+         nam   Printer
+         ttl   CoCo 3 Serial Printer Driver
 
          ifp1
          use   defsfile
          endc
 
 tylg     set   Drivr+Objct   
-atrv     set   ReEnt+rev
+atrv     set   ReEnt+Rev
 rev      set   $01
-edition  set   12
-
-         mod   eom,name,tylg,atrv,start,size
+edition  set   13
 
-u0000    rmb   29
-u001D    rmb   1
-u001E    rmb   1
-u001F    rmb   1
-size     equ   .
-         fcb   $03 
+         mod   eom,name,tylg,atrv,Start,Size
+
+         fcb   READ.+WRITE.
 
 name     fcs   /PRINTER/
-         fcb   edition
+         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   .
+
+* Baud Rate Delay Table
+BaudDly  equ   *
+         IFEQ  NitrOS9
+* OS-9 Level Two delay values (1.89MHz)
+         fdb   $090C    110 baud
+         fdb   $034C    300 baud
+         fdb   $01A2    600 baud
+         fdb   $00CE    1200 baud
+         fdb   $0062    2400 baud
+         fdb   $002E    4800 baud
+         fdb   $0012    9600 baud
+         fdb   $0003    32000 baud
+         ELSE   
+* NitrOS-9 Level Two delay values (1.89MHz)
+         fdb   $090C    110 baud (Unchanged, unknown)
+         fdb   $03D0    300 baud
+         fdb   $01A2    600 baud (Unchanged, unknown)
+         fdb   $00F0    1200 baud
+         fdb   $0073    2400 baud
+         fdb   $0036    4800 baud
+         fdb   $0017    9600 baud
+         fdb   $0003    32000 baud (Unchanged, unknown)
+         ENDC
+
 
 start    equ   *
-         lbra  L006E
-         lbra  L0028
-         lbra  L002C
-         lbra  L005B
-         lbra  L0057
-         lbra  L006C
-L0028    comb  
-         ldb   #$CB
-         rts   
-L002C    ldb   >MPI.Slct
-         andb  #$33
-         pshs  b
-         ldb   #$33
-         stb   >MPI.Slct
-         tst   >$FF52
-         bmi   L004A
-L003D    sta   >$FF52
-         sta   >$FF52
+         lbra  Init
+         lbra  Read
+         lbra  Write
+         lbra  GetStt
+         lbra  SetStt
+Term     equ   *
+         clrb
+         rts
+
+Init     orcc  #IntMasks
+         ldx   #$FF20
+         clr   $01,X
+         ldd   <$2C,Y     get number of columns/rows
+         std   <V.COL,U
+         lda   #$FE
+         sta   ,X
+         lda   #$36
+         sta   $01,X
+         lda   ,X
+         andcc #^IntMasks
+         ldd   <$26,Y     parity and baud rate
+         lbsr  L0138      setup parity/baud in device memory
+         lbsr  L0104      get low bit of $FF22 into carry
+         lbcs  L0100      it's the ready flag
+* clear out buffer
+         leax  V.BUFF,u   room for 128 blocked processes
+         ldb   #$80
+I010     clr   ,x+        we're more concerned with room
+         decb             than with speed, so we don't use TFM
+         bne   I010
+         rts
+
+L005F    ldb   <PD.BAU,Y     PD.BAU
+         andb  #$0F		keep lower nibble
+         cmpb  #$07       get baud rate
+         lbhs  Read
+         aslb  
+         leax  <BaudDly,PCR table of delay times
+         ldx   b,X
+         stx   <V.WAIT,U
+         clrb  
+         rts
+
+Bit_2    ldb   #$02
+L007D    stb   >$FF20
+L0080    pshs  d
+         ldd   <V.WAIT,U get wait count for baud rate
+L0085    equ   *
+         IFNE  H6309
+         decd             count down by one
+         ELSE
+         subd  #$0001
+         ENDC
+         bne   L0085
+         puls  pc,d
+
+Write    equ   *
+         leax  V.BUFF,u   point to the buffer
+         ldb   V.BUSY,u   get my process number
+         tst   ,x         get allowed process number
+         bne   W010       if not zero, else
+         stb   ,x         I'm the only one allowed to use it
+
+W010     cmpb  ,x         am I allowed to use /p?
+         beq   W030       if yes, go write a character
+
+***************************************************************
+* WARNING: If more than 128 processes try to use the printer,
+* this will CRASH BADLY.  Since Level II on the Coco is limited
+* to 32 processes, I don't think it's a problem.
+***************************************************************
+
+W020     tst   ,x+        if not, find the first non-zero entry
+         bne   W020
+         stb   -1,x       and save my process number at the first zero
+         pshs  a
+         lda   V.BUFF,u   process that's allowed to use /p
+         sta   V.BUSY,u   make it the busy one
+         ldb   #$01       wake it up
+         os9   F$Send     send a signal to wake it
+         IFNE  H6309
+         tfr   0,x
+         ELSE
+         ldx   #$0000
+         ENDC
+         os9   F$Sleep    and go to sleep forever
+         puls  a          restore character to be sent, and continue
+
+W030     bsr   L005F      set up baud rate, etc in memory
+         bcs   L00CA
+         pshs  a
+         bsr   L00CB      make sure that the device is ready
+         puls  a
+         bcs   L00CA      if the device is not ready
+         IFNE  H6309
+         lde   #$09       9 bits to send out
+         ELSE
+         pshs b,a
+         lda  #$09
+         sta  1,s
+         puls a
+         ENDC
+         orcc  #IntMasks  turn off interrupts
+         tst   <V.BIT,U   number of bits
+         beq   L00AC      if 7 bits, count down by one
+         IFNE  H6309
+         dece             initially send out start bit
+         ELSE
+         dec   ,s
+         ENDC
+
+L00AC    bsr   L007D      write B to $FF20 and wait
+         clrb
+         lsra             move A into carry
+         rolb
+         rolb
+         IFNE  H6309
+         dece             count down on the number of bits to send
+         ELSE
+         dec   ,s
+         ENDC
+         bne   L00AC
+         IFEQ  H6309
          puls  b
-         stb   >MPI.Slct
+         ENDC
+         ldb   <V.PAR,U   space/mark parity
+         beq   L00BC      0=no parity
+         andb  #$FE       1=space, 0=mark parity
+* should be andb #$FD I think...
+         bsr   L007D      dump out a parity byte
+L00BC    bsr   Bit_2      and a stop bit
+         tst   <V.STP,U   do another one?
+         beq   L00C9
+         bsr   Bit_2      yes, dump out another stop byte
+L00C9    andcc #^IntMasks
+L00CA    rts
+
+L0104    pshs  b
+         ldb   >$FF22     get a byte
+         lsrb  
+         puls  pc,b
+
+L00CB    equ   *
+         IFNE  H6309
+         clrd
+         ELSE
+         clra
+         clrb
+         ENDC
+         std   <V.TRY,U
+L00D0    ldd   #$0303
+L00D3    bsr   L0104      get device ready status
+         bcs   L00DE      if not ready, wait for a bit
+         IFNE  H6309
+         bsr   L0080      wait
+         ELSE
+         lbsr  L0080      wait
+         ENDC
+         decb  
+         bne   L00D3      try again
          clrb  
          rts   
-L004A    ldx   #$0001
-         os9   F$Sleep  
-         tst   >$FF52
-         bpl   L003D
-         bra   L004A
-L0057    comb  
-         ldb   #$D0
+
+L00DE    lbsr  L0080      wait for a while
+         deca             try 3 times,
+         bne   L00D3
+         pshs  x
+         ldx   #$0001
+         os9   F$Sleep    sleep for the rest of this tick
+         puls  x
+         ldd   <V.TRY,U
+         IFNE  H6309
+         incd             we've tried once more and failed...
+         ELSE
+         addd  #$0001
+         ENDC
+         std   <V.TRY,U
+         ldb   <V.RTRY,U  number of retries to do
+         beq   L00D0      if unspecified, keep retrying
+         cmpb  <V.TRY,U   if exceeded number of retries,
+         bhi   L00D0      then we crap out
+
+L0100    comb  
+         ldb   #E$NotRdy
+         rts   
+
+GetStt   cmpa  #SS.EOF    end of file?
+         bne   L0112
+         clrb             if so, exit with no error
          rts   
-L005B    cmpa  #$26
-         bne   L0057
-         ldx   $06,y
-         clra  
-         ldb   <u001D,u
-         std   $04,x
-         ldb   <u001E,u
-         std   $06,x
-L006C    clrb  
+
+L0112    ldx   PD.RGS,Y
+         cmpa  #SS.ScSiz
+         beq   L0123
+         cmpa  #SS.ComSt
+         bne   L0173
+         ldd   <V.COM,U     get Com status
+         std   R$Y,X
+         clrb
+         rts
+
+* get screen size GetStt
+L0123    clra  
+         ldb   <V.COL,U
+         std   R$X,X
+         ldb   <V.ROW,U
+         std   R$Y,X
+         clrb
+         rts
+
+SetStt   cmpa  #SS.ComSt
+         bne   Close      if not, check if it's a close
+         ldx   PD.RGS,Y
+         ldd   R$Y,X
+* A = Parity byte
+* B = baud rate
+L0138    std   <V.COM,U     save parity, baud rate in com status
+         IFNE  H6309
+         clrd
+         ELSE
+         clra
+         clrb
+         ENDC
+         std   <V.PAR,U
+         sta   <V.STP,U
+         ldd   <V.COM,U
+         tstb
+         bpl   L014C
+         inc   <V.STP,U  do 2 stop bits
+L014C    bitb  #$40       make sure the bit is zero
+         bne   Read
+         bitb  #$20       0=8, 1=7 bits
+         beq   L0157
+         inc   <V.BIT,U
+L0157    bita  #$20
+         beq   L0169      if=0, no parity
+         bita  #$80
+         beq   Read       if high bit set (only for ACIA devices), error out
+         inc   <V.PAR,U     parity
+         bita  #$40
+         bne   L0169      1=space,
+         inc   <V.PAR,U  2=mark parity
+L0169    anda  #$0F
+         sta   <V.RTRY,U
          rts   
-L006E    ldd   <$2C,y
-         std   <u001D,u
-         lda   <$26,y
-         sta   <u001F,u
-         clrb  
-         rts   
+
+Read     comb  
+         ldb   #E$BMode
+         rts
+
+L0173    comb
+         ldb   #E$UnkSVc
+         rts
+
+Close    cmpa  #SS.Close  close the device?
+         bne   L0173
+         leax  V.BUFF,u   point to blocked process buffer
+
+C010     lda   1,x        get next process number
+         sta   ,x+
+         bne   C010       do until we have a zero byte
+
+         lda   V.BUFF,u   get the first process in the queue
+         beq   C020       if none left
+         ldb   #$01       wake up signal
+         os9   F$Send     re-start the blocked process
+
+C020     clrb
+         rts
 
          emod
 eom      equ   *