--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/level1/modules/rs232.asm	Thu Apr 04 16:34:12 2002 +0000
@@ -0,0 +1,299 @@
+********************************************************************
+* RS232 - CoCo bit-banger driver
+*
+* $Id$
+*
+* Ed.    Comments                                       Who YY/MM/DD
+* ------------------------------------------------------------------
+* 7      Tandy/Microware original version
+
+         nam   RS232
+         ttl   CoCo bit-banger driver
+
+* Disassembled 98/08/23 17:32:49 by Disasm v1.6 (C) 1988 by RML
+
+         ifp1
+         use   defsfile
+         use   scfdefs
+         endc
+
+tylg     set   Drivr+Objct   
+atrv     set   ReEnt+rev
+rev      set   $01
+edition  set   $07
+
+         mod   eom,name,tylg,atrv,start,size
+
+u0000    rmb   29
+u001D    rmb   1
+u001E    rmb   1
+u001F    rmb   1
+u0020    rmb   2
+u0022    rmb   2
+u0024    rmb   1
+u0025    rmb   1
+size     equ   .
+         fcb   $03 
+
+name     fcs   /RS232/
+         fcb   edition
+
+L0014    fcb   $04
+         fcb   $82 
+         fcb   $01
+         fcb   $A2 "
+         fcb   $00 
+         fcb   $CD M
+         fcb   $00 
+         fcb   $63 c
+         fcb   $00 
+         fcb   $2D -
+         fcb   $00 
+         fcb   $13 
+         fcb   $00 
+         fcb   $05 
+
+start    lbra  Init
+         lbra  Read
+         lbra  Write
+         lbra  GetStat
+         lbra  SetStat
+         lbra  Term
+
+* Init
+*
+* Entry:
+*    Y  = address of device descriptor
+*    U  = address of device memory area
+*
+* Exit:
+*    CC = carry set on error
+*    B  = error code
+*
+Init     pshs  cc
+         orcc  #IntMasks
+         ldx   #PIA.U8
+         clr   $01,x
+         ldd   <IT.COL,y		get col/row bytes
+         std   <u0024,u
+         lda   #$FE
+         sta   ,x
+         lda   #$36
+         sta   $01,x
+         lda   ,x
+         ldd   <IT.PAR,y		get parity/baud
+         lbsr  L014D
+         puls  cc
+         clrb
+
+* Term
+*
+* Entry:
+*    U  = address of device memory area
+*
+* Exit:
+*    CC = carry set on error
+*    B  = error code
+*
+Term     rts
+
+* Read
+*
+* Entry:
+*    Y  = address of path descriptor
+*    U  = address of device memory area
+*
+* Exit:
+*    A  = character read
+*    CC = carry set on error
+*    B  = error code
+*
+Read     bsr   L00B1
+         bcs   L00CD
+         ldb   #$08
+         pshs  b,cc
+         tst   <u001E,u
+         beq   L0066
+         dec   $01,s
+L0066    bra   L006E
+L0068    ldx   #$0001
+         os9   F$Sleep
+L006E    lda   >PIA.U8+2
+         lsra
+         pshs  x,a
+         lda   >$FF69
+         bpl   L0091
+         lda   >PIA.U8+3
+         bita  #$01
+         beq   L0091
+         bita  #$80
+         beq   L0091
+         orcc  #Entire
+         leax  <L0091,pcr
+         pshs  x
+         pshs  u,y,x,dp,b,a,cc
+         jmp   [D.SvcIRQ]
+L0091    puls  x,a
+         bcs   L0068
+         orcc  #IntMasks
+         clra
+         bsr   L00DA
+L009A    bsr   L00D3
+         ldb   >PIA.U8+2
+         lsrb
+         rora
+         dec   $01,s
+         bne   L009A
+         bsr   L00DA
+         tst   <u001E,u
+         beq   L00AD
+         lsra
+L00AD    puls  b,cc
+         clrb
+         rts
+L00B1    pshs  a
+         lda   <PD.BAU,y
+         anda  #$0F
+         cmpa  #$07
+         bcc   L00C9
+         lsla
+         leax  >L0014,pcr
+         ldd   a,x
+         std   <u0020,u
+         clrb
+         puls  pc,a
+L00C9    ldb   #$CB
+         puls  a
+L00CD    orcc  #Carry
+         rts
+L00D0    stb   >PIA.U8
+L00D3    pshs  b,a
+         ldd   <u0020,u
+         bra   L00E1
+L00DA    pshs  b,a
+         ldd   <u0020,u
+         lsra
+         rorb
+L00E1    subd  #$0001
+         bne   L00E1
+         puls  pc,b,a
+
+* 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    bsr   L00B1
+         bcs   L00CD
+         ldb   #$09
+         pshs  b,cc
+         orcc  #IntMasks
+         tst   <u001E,u
+         beq   L00F9
+         dec   $01,s
+L00F9    andcc #^Carry
+L00FB    ldb   #$02
+         bcs   L0100
+         clrb
+L0100    bsr   L00D0
+         lsra
+         dec   $01,s
+         bne   L00FB
+         ldb   <u001D,u
+         beq   L0110
+         andb  #$FE
+         bsr   L00D0
+L0110    ldb   #$02
+         bsr   L00D0
+         tst   <u001F,u
+         beq   L011D
+         ldb   #$02
+         bsr   L00D0
+L011D    puls  pc,b,cc
+
+* GetStat
+*
+* Entry:
+*    A  = function code
+*    Y  = address of path descriptor
+*    U  = address of device memory area
+*
+* Exit:
+*    CC = carry set on error
+*    B  = error code
+*
+GetStat  cmpa  #SS.EOF
+         bne   L0125
+L0123    clrb
+         rts
+L0125    ldx   PD.RGS,y
+         cmpa  #SS.ScSiz
+         beq   L0136
+         cmpa  #SS.ComSt
+         bne   L0183
+         ldd   <u0022,u
+         std   R$Y,x
+         bra   L0123
+L0136    ldx   PD.RGS,y
+         clra
+         ldb   <u0024,u
+         std   R$X,x
+         ldb   <u0025,u
+         std   R$Y,x
+         bra   L0123
+
+* 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
+*
+SetStat  cmpa  #SS.ComSt
+         bne   L0183
+         ldx   PD.RGS,y
+         ldd   R$Y,x
+L014D    std   <u0022,u
+         clra
+         clrb
+         std   <u001D,u
+         sta   <u001F,u
+         ldd   <u0022,u
+         tstb
+         bpl   L0161
+         inc   <u001F,u
+L0161    bitb  #$40
+         bne   L017F
+         bitb  #$20
+         beq   L016C
+         inc   <u001E,u
+L016C    bita  #$20
+         beq   L017E
+         bita  #$80
+         beq   L017F
+         inc   <u001D,u
+         bita  #$40
+         bne   L017E
+         inc   <u001D,u
+L017E    rts
+L017F    comb
+         ldb   <E$BMode
+         rts
+L0183    comb
+         ldb   #E$UnkSvc
+         rts
+
+         emod
+eom      equ   *
+         end
+