* BAUD.A     PTDOS terminal baud rate change coomand
* by TMQ  6/15/79   for P.T. 3P + S  I/O board
* form: BAUD #
* where # = 3 for  300 baud
*         = 9 for 9600 baud
* board must be jumpered for these speeds
*
 COPY NPTDEFS  get system definitions
 ORG CXBUF  load address
 XEQ START  start address
*
START MVI A,PSOPT read characters until delimiter
 LXI D,BUFPS  point to parameter scanner buffer
 CALL PSCAN  parameter scanner
 JC ERRPS  scanner error
 JZ ERRSY  syntax error
 CPI 0DH  carriage return
 JZ OKDEL  CR is a valid delimiter
 CPI ';'  semicolon
 JNZ ERRSY  if not a ; then invalid delimiter
OKDEL MOV A,C  get # of characters scanned
 CPI 1  is it a one
 JNZ ERRSY  no, syntax error
 LXI H,DONE  set up for return
 LDA BUFPS  get character scanned
 CPI '3'  300 baud
 JZ B300  set if match
 CPI '9'  9600 baud
 JZ B9600  set if match
* error handlers follow
ERRSY MVI A,0  control word
 LXI H,-1  no 2nd line message
 CALL UTIL  system utility call
 DB UXOP  explain error
 JMP ABORT  error return
 DB -1  no operation code
ERRCD DB 2AH  error code, command syntax error unless patched
* drastic error handler
ABORT CALL SYS  system call, normal return, not used
 DB RESOP  drastic return to DOS and reset all
ERRPS MOV A,E  move error code
 STA ERRCD  store it
 JMP ERRSY  let system utility handle error
* set baud rate routines
B300 MVI A,04H  9600 baud control word
 PCHL  go to DONE
B9600 MVI A,08H  300 baud control word
DONE OUT 0  send to control port
 CALL SYS  system call
 DB RETOP  normal return to system
BUFPS DS 20  parameter scanner buffer
 END