PAGE
*
*
*******************************************
*
*
*
*
*               COMMAND INTERPRETER
*               *********************
*
*
*    SOME CHARACTERS
*
CR EQU 13  ASCII CR
LF EQU 10  ASCII LF
SEMI EQU 59  SEMICOLON
COMMA EQU ','
SLASH EQU '/'
NSIGN EQU '#'
ZCHR EQU '0'
ASTRC EQU '*'
*
*********************
*
*
*  EOF ON INPUT FILE, IF CIFILE = 0 (CONSOLE), THEN
*     DO A CLOSE ALL, ELSE DO A SHORT RESET.
*
CIEIF LDA CIFILE
 ORA A  CHECK FOR ZERO
 JNZ USRES  NOT ZERO, DO A SHORT RESET TO MOVE THE CONSOLE
 MVI A,255  CLOSE ALL FILES
 CALL SYS
 DB CAOP
 JMP CIABT
 JMP USRES  WHY NOT?
*
*********************
*
*
*      "RETURN" ENTRY
*
*  PROCESS NEXT COMMAND, IF ANY
*  IF NONE, RETYPE PROMPT
*
RETURN LXI SP,CISTK
 CALL INRST  RESET INT TRAPS
 LHLD CRTRAP  CHECK RETURN TRAP
 INX H  IF =-1, NOTHING TO DO
 MOV A,H
 ORA L
 JZ CI50  NONE
 DCX H  <> -1, JUMP TO ADDRESS
 PUSH H  HERE WE GO
 LXI H,-1
 SHLD CRTRAP  CLEAR TRAP
 RET .  GO TO TRAPPER
*
*********************
*
*
*  SET ERROR TRAPS TO CI STANDARD AND RESET INT TRAPS
*
CIRST LXI H,0
 SHLD AERR
 SHLD FERR
 DCX H
 SHLD EERR
*
*  RESET BOTH INTERRUPT TRAPS
*
*  RETURN HL=-1
*
INRST LXI H,0
 SHLD DSKRD  SET DISKREADY TO 0
 DCX H  NOW FOR -1
 SHLD BDSK1
 SHLD BDSK2
 RET .  MUST RETURN WITH -1
*
*********************
*
*
*      ECHO CHARACTER TO CI LOG FILE
*
*  COME WITH CHAR IN A, AND RETURN THAT WAY
*
CRECHO MVI A,CR  ENTRY POINT TO ECHO A CARRIAGE RETURN
*
ECHOUT MOV B,A
 LDA ECFILE
 CALL WB  WRITE IT OUT
 CALL CI98  PANIC!!!
 MOV A,B
 RET
*
*********************
*
*
*       RETURN AND SET TRAP
*
*  COME HERE WITH TRAP ADDRESS IN USER HL
*
RETRAP LHLD UHL
*   SET CRTRAP AND FALL INTO CI
 SHLD CRTRAP
*
*********************
*
*
*  READ AND PROCESS A COMMAND
*
CI LXI SP,CISTK  SETUP STACK
*
CI50 LXI H,CIMSG  RESET PROMPT STRING
 SHLD TDPRO
 CALL CIRST
*
*   EAT LEADING BLANKS AND ","'S
*
CI51 CALL CIBNK
 JZ CIEIF  ZERO INDICATES EOF
 CALL CIBUP  WASN'T " " OR ","... BACK UP 1 CHAR
*
*   ECHO THE COMMAND
*
 LDA SWECH
 RRC
 JNC CI59  NO ECHO
 LXI H,0
 SHLD CECT  SET COUNT TO ZERO
*
CI53 LDA ECFILE  GET ECHO FILE NUMBER
 DCR A
 CZ CRECH  DO A CR IF IT'S #1
 XRA A
 STA CERC  CRLF COUNT TO ZERO
*
CI55 LDA CIFILE
 CALL RB
 JMP CI57
 CALL ECHOUT  PRINT CHAR
 LHLD CECT
 INX H
 SHLD CECT  INCREMENT CHARACTER COUNT
*
 CPI CR
 JZ CI58  CR -- DONE
 CPI ';'
 JZ CI57  ; -- DONE
*
 LXI H,CERC
 INR M  BUMP LINE POSITION
 MVI A,72  DO AUTO CRLF FOR TTY'S ETC
 CMP M
 JNC CI55  NOT PAST, KEEP GOING
 CALL CRECH  PAST 70, TYPE CR
 JMP CI53  LOOP
*
*********************
*
*
*   DONE WITH ECHO, MOVE BACK
*
CI57 CALL CRECHO  TYPE A CR
*
CI58 LHLD CECT
 MOV B,H
 MOV C,L  BC HAVE NUMBER OF CHARACTERS TYPED
 LDA CIFILE
 MVI D,128
 CALL SYS
 DB SPAOP  SPACE BACK
 JMP CIABT  ERROR- CAN'T BACK UP
*
*
*
*    INITIALIZE FOR COMMAND READ
*
CNBF EQU DKBUF  PUT NAME OUT OF THE WAY!
*
CI59 LXI H,CNBF
 SHLD CPNT  SET STORAGE POINTER
 MVI A,NMLEN+2
 STA CICNT  SET MAX CHAR COUNT
 MVI A,1
 STA XQFLG  SET XEQ FLAG
*
*  YES, HERE WE AGAIN EAT BLANKS AND COMMAS
*
 CALL CIBNK
 JZ USRES  END OF FILE
 JMP CI65  GO PROCESS THE FIRST CHR
*
*
*     READ COMMAND
*
CI60 LDA CIFILE
 CALL RB
 JMP USRES  SHORT RESET TO CONSOLE
*
CI65 CPI CR
 JZ CI68  ITS A CR, GO PROCESS
 CPI SEMI
 JZ CI68  ITS A SEMICOLON, GO PROCESS
 CPI BLNK
 JZ CI71  SPACE, GO PROCESS
 CPI COMMA
 JZ CI67
 MOV B,A
 LDA CICNT
 ORA A  ANY MORE CHARACTERS NEEDED?
 JZ CI60  NO, JUST IGNORE
 DCR A
 STA CICNT  YES, COUNT DOWN
 LHLD CPNT
 MOV M,B  STORE CHARACTER
 INX H
 MVI M,0
 SHLD CPNT  UPDATE POINTER
 JMP CI60
*
*
*   COMMA, INHIBIT EXECUTION
*
CI67 XRA A
 STA XQFLG
 JMP CI71  GO PROCESS
*
*********************
*
*
*   EAT COMMA'S AND SPACES FROM CI FILE
*
CIBNK LDA CIFILE
 CALL RB
 NOP
 XRA A  SET UP FOR EOF RETURN
 RET
 CPI BLNK
 JZ CIBNK
 CPI COMMA
 RNZ
 JMP CIBNK  LOOP FOR " ","," OR EOF
*
*********************
*
*
*   BACKUP ONE CHARACTER IN CIFILE
*
CIBUP LDA CIFILE
 LXI B,1
 MVI D,128
 CALL SYS
 DB SPAOP  BACKUP 1 CHAR
 JMP CIABT  SERIOUS ERROR
 RET
*
*********************
*
*
*   CLOSE LOAD FILE
*
CICLO LDA CICNT
 CALL SYS  CLOSE
 DB CLOOP
 JMP CIABT  ERROR
 RET
*
*********************
*
*
*      PROCESS COMMAND
*
*  COME HERE FOR CR AND ;
*  BACKUP SO ROUTINE CAN SEE THE CHARACTER
*
CI68 LDA CICNT  CHECK FOR NULL COMMAND
 CPI NMLEN+2
 CNZ CIBUP  BACKUP IF NON-NULL, IF NULL FOLLOWING TEST WILL
*                            DO.
CI71 LDA CICNT
 CPI NMLEN+2  CHECK FOR NULL COMMAND
 JZ RETURN  YES
*
*  OPEN FILE
*
 LXI D,CNBF  NAME POINTER
CI71A LXI H,-1
 SHLD AERR  GET MOST ERRORS
 INX H  =0, SYSTEM BUFFER OPTION
 CALL SYS  OPEN FILE
 DB OPEOP
 JMP CIOER  TRY TO REPORT THE ERROR
*
 STA CICNT  SAVE FILE NUMBER
 LXI H,0
 SHLD AERR  SET NORNAL ERROR TRAPPING
*
*  CHECK FILE TYPE
*
 LDA FTYPE
 ANI IMTYPE
 JNZ CI94  NOT IMAGE FILE, CANT LOAD
*
*  LOAD THE FILE
*
CI75 LDA CICNT  GET FILE NUMBER
 LXI B,4  4 BYTES
 LXI D,CBUF  INTO CBUF
 CALL SYS  READ BLOCK
 DB RBLOP
 JMP CI80  EOF ENCOUNTERED
*
*
*   NORMAL RETURN...GET COUNT AND DEST
*
 LHLD CBUF  WE READ IT TO HERE
 MOV B,H
 MOV C,L  BC HAVE COUNT
 LHLD CBUF+2  HL GET DESTINATION
 MOV A,B  CHECK FOR ZERO COUNT
 ORA C
 JZ CI96  YES, PROBABLY UTILITY
 LDA CICNT  A WILL BE NUMBER
 XCHG .  DE HAVE ADDRESS
 CALL SYS  A STILL HAS NUMBER
 DB RBLOP
 JMP CI89  BAD LOAD FILE
 JMP CI75  OK, DO NEXT BLOCK
*
*********************
*
*
*  CHECK FOR SELF START
*
CI80 CPI EER0  CHECK FOR EOF
 JNZ CI98  NOT EOF, VERY BAD
 MOV A,C
 CPI 2  ARE 2 BYTES LEFT
 JZ CI95  YES, SELF START
*
*  CLOSE FILE
*
 CALL CICLO
 LDA XQFLG  IF XQFLG=0 (=> COMMA),
 ORA A  THEN JUST HANDLE NEXT
 JZ CI59  WITHOUT ECHO
 JMP RETURN  TRY NEXT COMMAND
*
*********************
*
*
CI94 MVI A,CIER1  NOT IMAGE FILE
 JMP CI90
*
*
*    BAD LOAD FILE, CLOSE FIRST
*
CI89 MVI A,CIER0
*
*    COME HERE WITH ERROR # IN A
*
*
CI90 PUSH PSW  SAE ERROR NUMBER
 CALL CICLO  CLOSE THE LOAD FILE
 POP PSW  A = ERROR #
*
CIOER STA ERCD  SET ERROR NUMBER FOR UTILITY CALL
 MVI A,CCLDE  =CODE FOR LOADER
 STA EOPR  SET OPERATION
 MVI A,0  MESSAGE AND NO RETURN
 LXI H,CNBF  -> FILE NAME
 JMP ERRP9  GIVE MESSAGE
*
*********************
*
*
*    CATESTROPHIC ERROR
*
CI98 POP H  SHOW ADDRESS
CI99 MVI A,CSER0  CATESTROPHIC
*
*********************
*
*
*    ABORT.  USE EXISTING REGISTERS
*
CIABT PUSH PSW  RESTORE ECHO FILE TO CONSOLE
 MVI A,1
 STA ECFILE
 POP PSW
 CALL SYS
 DB ABTOP
*
*********************
*
*
*
*     START UP USER PROGRAM
*
*  CLOSE THE FILE
*
CI95 CALL CICLO
 LHLD CBUF  SET START ADDRESS
*
*  COME HERE WITH HL EQUAL TO START ADDRESS
*  THE FILE WILL NOT BE CLOSED
*
CI96 LDA XQFLG
 ORA A
 JZ CI59  COMMAND ENDED WITH "," - LOAD NEXT FILE
 LDA XA
 PUSH H
 LHLD XHL
 RET
*
 PAGE
*
*
*******************************************
*
*
*
*
*         CONSOLE TELETYPE DRIVER
*
*
SSTA EQU 0FAH  SOL STATUS PORT
USTA EQU 0
UDAI EQU 0FCH  SOL INPUT PORT
UDAO EQU 1
INRDY EQU 1  SOL READY BIT
OTRDY EQU 128
*
BUFT EQU 80  BUFFER SIZE IN BYTES (255 MAX)
BUFT2 EQU 40  OUTBUF SIZE
*
*********************
*
*       DRIVER TABLE
*
TDRIV DW TDRL  READ BLOCK
 DW TDRL  READ NEXT
 DW IDAC  READ LAST, NO CAN DO
 DW TDWL  WRITE BLOCK, NEXT
 DW TDWL  WRITE BLOCK
 DW TDNGO  REWIND
 DW TDNGO  EOF
 DW TDNGO  CLOSE
 DW IDAC  SEEK
 DW TDCTL  CONTROL
 DW 0  BUFFER SIZE HOLDER
 DB 1  IMMEDIATE TRANSFER OPTION
 DW TDNGO  INITIALIZE, ETC... A CONVINIENT RETURN
*
*******************************************
*
*
*
*     CONSOLE INPUT DRIVER DISPATCH POINT
*
CONIN LDA STFLG  CHARACTER WAITING?
 ORA A
 JZ CONI1  NO
 XRA A  =0
 STA STFLG  CLEAR FLAG
 LDA INBYT  RETURN WAITING CHR
 JMP CONI2  GO
*
*********************
*
*
*  GET CHR FROM RCH DRIVER
*
CONI1 PUSH H  SAVE HL
 LXI H,CONI2  SETUP RETURN POINT
 XTHL .  RETURN ADDRESS NOW ON STACK
 PUSH H
 LHLD RCH  GET READ CHARACTER ADDRESS
 XTHL .  GET BACK HL
TDNGO RET .  DISPATCH TO RCH
*
*********************
*
*
*  RETURN HERE WITH CHARACTER IN A
*
CONI2 STA CONCH  SAVE IT AWAY
 PUSH B  DON'T DISTURB BC
 CALL UPSH  UPSHIFT CHARACTER
 LDA CONCH  BINARY, RELOAD CHAR
 POP B  NON-BINARY RETURN
 STA INBYT  SAVE BYTE FOR POSSIBLE LATER USE
 RET
*
*********************
*
*
*   READ SINGLE BYTE
*
CIRCH CALL CITCH  GET THE STATUS
 JZ CIRCH  WAIT
 IN UDAI  READ IT
 PUSH PSW  SAVE FOR SWITCH TEST
 LDA SWBIO  BINARY I/O?
 RRC
 JC CIR20  YES!
 POP PSW  NO
 ANI 127  MASK PARITY
 RET
*
*
CIR20 POP PSW
 RET
*
*******************************************
*
*
*        CONSOLE STATUS TEST DISPATCH POINT
*
CONST PUSH H  SAVE HL
 LXI H,CONT20
 PUSH H  SETUP RETURN ADDRESS
 LHLD SCH
 PCHL .  DISPATCH TO SCH
*
*
* COME HERE AFTER TEST WITH Z/NZ SET
*
CONT20 POP H  RESTORE HL
 JNZ CONT30  GOT A CHARACTER WAITING, USE IT
 LDA STFLG  NO REAL CHAR, WHAT ABOUT A PSEUDO ONE
 ORA A
 RET .  GO WITH FLAGS SET
*
*
*    A REAL CHAR, CLEAR PSEUDO CHAR FLAG
*
CONT30 XRA A
 STA STFLG
 INR A  DON'T FORGET ABOUT THE REAL ONE
 RET
*
*
*    CONSOLE TEST INPUT CHAR
*
CITCH IN SSTA
 CMA
 ANI INRDY
 RET .  FLAGS SET
*
*******************************************
*
*
*
*   CONSOLE OUTPUT CHARACTER ROUTINES
*
CONOUT STA CONCH  SAVE CHARACTER
 CALL UPSH  UPSHIFT CHARACTER
 JMP CON40  RETURN HERE => BINARY SWITCH SET, JUST OUTPUT
 STA CONCH  SAVE UPDATED CHARACTER
*
*  IF CR, SET CRSEEN FLAG AND OUTPUT NULLS
*
 CPI CR
 JNZ CON20  NOT A CR
 STA CRSEEN  SET FLAG
 JMP CON90  OUTPUT THE CHARACTER
*
*
*  NOT A CR, SEE ABOUT LF
*
CON20 CPI LF
 JZ CON30  YES, IT WAS
*
*  NOT A LF, IF LAST WAS CR, OUTPUT LF AND CLEAR CRSEEN
*
 MOV B,A
 LDA CRSEEN
 ORA A
 MOV A,B
 JZ CON40  LAST WASN'T A CR, JUST OUTPUT CHAR
 MVI A,LF  OUTPUT A LF TO PREVENT OVERPRINTING
 CALL CON90
*
CON30 XRA A
 STA CRSEEN  CLEAR CRSEEN FLAG
*
*  OUTPUT CHAR IN CONCH
*
CON40 LDA CONCH
CON90 CPI LF  LF?
 JZ CON91  YES, FOLLOW WITH NULLS
CONXO MOV B,A
 PUSH H  SETUP CALL TO WCH ROUTINE
 LHLD WCH  -> ROUTINE
 XTHL
 RET .  GET US THERE
*
*
*  SEND NULLS AFTER LF
*
CON91 CALL CONXO  TYPE TH ELF
 LDA NULLS  A=LF BEFORE SO NO NEED TO SAVE
 PUSH D  SAVE DE
 MOV D,A
 ORA A
 JZ CON93  NONE TO DO
*
CON92 XRA A
 CALL CONXO  SEND NULL
 DCR D  COUNT DOWN
 JNZ CON92  MORE
*
CON93 POP D
 MVI A,LF  RETURN WIT LF FOR CONSISTANCY
 RET .  NOW RETURN FOR REAL
*
*
*
*  THIS DOES THE ACTUAL OUTPUT.  CONTROL USUALLY COMES HERE
*          THROUGH (WCH) BY CON90.
*
CIWCH IN 0F8H
STBYT EQU $-1
 DB 0  PATCH ROOM
 ANI OTRDY
 JZ CIWCH
 MOV A,B  GET CHR
 OUT 0F9H
DABYT EQU $-1
 RET
*
*******************************************
*
*
*          UPSHIFT ASCII SUBROUTINE
*
*    COME HERE WITH CHAR IN CONCH
*
*    <RETURN>  BINARY, NO CHANGE, CHAR IN CONCH  (NOT IN A)
*    <RETURN>  OK, POSSIBLY UPDATED CHARACTER IN A
*
UPSH LDA SWBIO  BINARY CONSOLE?
 RRC
 RC .  YES, SKIP THE WHOLE THING AND LET CON.. KNOW
*
 LDA SWUPS  SEE IF UPSHIFT REQUESTED
 RRC
 LDA CONCH  A=CHAR
 CC UPSH1  CHECK IT
 JMP RX2  NO, SKIP IT
*
*
*  SEE ABOUT UPSHIFTING CHAR
*
UPSH1 CPI 123  ="z"+1
 RNC .  >"z", NO CHANGE
 CPI 97  ="a"
 RC .  <"a", NO CHANGE
 SBI 32  UPSHIFT
 RET .  OK
*
*******************************************
*
*  CI PROMPT MESSAGE
*
CIMSG DB CR
 DB LF
 DB ASTRC  THE ACTUAL PROMPT
 DB 0  END OF MESSAGE
*
*
*          OUTPUT STRING TO CONSOLE
*
*  LIKE OUST BUT COME WITH HL -> STRING
*  THE STRING TERMINATES WITH A ZERO BYTE AND CONTROL
*   RETURNS TO CALL+1
*
OUSTH MOV A,M
 ORA A
 RZ
 INX H
 CALL CONOUT  PRINT
 JMP OUSTH
*
 PAGE
*
*
*******************************************
*
*
*  -----------------  TTY DRIVER FOR CONSOLE -----------
*
TDWB EQU CONOUT  OUTPUT CHARACTER ROUTINE
*
*        WRITE BLOCK
*
*  BUFFER ADDR IN HL, COUNT IN DE
*
TDWL MOV A,E
 ORA A  TEST COUNT
 JZ TDW30  ZERO, => DONE
 MOV A,M  GET CHAR
 CALL TDWB  PRINT
 INX H  BUMP POINTER
 DCR E  DEC. COUNT
 JMP TDWL
*
*
*  RETURN A ZERO COUNT
*
TDW30 LXI H,0
 JMP RX2  RETURN CALL+2
*
*
*         READ BLOCK
*
*  COME WITH BUFF IN HL, COUNT IN DE
*
*  PRINT PROMPT
*
TDRL PUSH H
 PUSH D  SAVE IMPORTANT NUMBERS
 LHLD TDPRO  -> PROMPT MESSAGE
 CALL OUSTH  PRINT IT
 POP D
 POP H
 MVI D,0  INITIALIZE CHAR COUNT
*
TDRL2 CALL CONIN  GET A CHARACTER
 CPI CTRLX  CANCEL?
 JZ TDRLC  YES, DELETE LINE
 CPI BSP  BACKSPACE?
 JZ TDRLB  YES, BACKSPACE
 MOV B,A
 MOV A,D  ONLY CHECK CTRL-C IF D=0 (1ST CHAR)
 ORA A
 JNZ TDRL3  SKIP TEST
 MOV A,B
 CPI CTRLC  CTRL-C ?
 JZ TDRLE  YES, EOF
*
TDRL3 MOV A,E
 ORA A
 JZ TDRLF  BUFFER IS FULL
 MOV M,B  STORE CHAR
 MOV A,B
 INX H
 CALL CONOUT  ECHO
 INR D  COUNT UP
 DCR E  COUNT DOWN
 CPI CR  IS IT A CR?
 JZ TDRLQ  CR, QUIT
 JMP TDRL2  GET NEXT.
*
*
*  DELETE ENTIRE LINE
*
TDRLC MVI A,'!'  TYPE !,CR, LF
 CALL TDWB
 MVI A,CR
 CALL TDWB
 MVI A,LF
 CALL TDWB
*
*  MOV BUFFER POINTER AND COUNTS BACK TO BEGINNING
*
TDRL5 MOV A,D
 ORA A
 JZ TDRL2
 INR E  MORE CHARS AVAIL
 DCX H  MOVE BACK BUFFER PTR
 DCR D  COUNT DOWN CHARS
 JMP TDRL5
*
*
*  BACK SPACE
*
TDRLB MOV A,D
 ORA A
 JZ TDRLF  ITS EMPTY, FORGET IT
 DCX H  ADJUST POINTER
 DCR D  AND
 INR E  COUNTS.
 MVI A,LARO
 CALL TDWB  TYPE BACK ARROW
 JMP TDRL2  AND GO ON
*
*
*  END OF FILE ENCOUNTERED.
*
*         ****  THIS ROUTINE USED AS INIT ENTRY POINT ***
*               WATCH OUT!!
*
TDRLE RET .  THATS IT
*
*  BUFFER IS FULL (OR EMPTY)
*
TDRLF MVI A,BELL
 CALL TDWB  DING
 JMP TDRL2  TRY AGAIN
*
*  CARRIAGE RETURN-QUIT.
*
TDRLQ MOV L,D  COUNT IN HL
 MVI H,0
 JMP RX2
*
 PAGE
*
*
*******************************************
*
*
*
*           TTY CONTROL/STATUS OPERATION
*
*  HANDLES STATUS AND PROMPT SET REQUESTS
*
TDCTL ORA A
 JNZ TDCT2  NOT STATUS REQUEST
*
 MVI A,PALO+PNAT+PATR+PDEL  PROTECT WORD
 LXI D,SBDUP+SBIAT+SBPRO*256  TYPE WORD
 RET .  THAT'S ALL
*
*
* CHECK IF PROMPT SET OPERATION
*
TDCT2 CPI 2
 JNZ TDCER  NO, ERROR
 SHLD TDPRO  YES, SET PROMPT POINTER
 RET
*
*
TDCER CALL ERRL2
 DB ERNCT  CAN'T DO THAT CONTROL OPERATION
*
*******************************************
*
*
*
*  HERE ARE SOME USEFUL ASCII CHARACTERS
*
BSP EQU 127  RUBOUT
CTRLC EQU 3  CONTROL-C
CTRLX EQU 24  CONTROL-X
BELL EQU 7  BELL
BSLSH EQU 92  BACK-SLASH
LARO EQU 95  LEFT ARROW
BLNK EQU 32  SPACE
*
 PAGE
*
*
*******************************************
*
*
*
*
*              UTILITY OPERATION MANAGER
*            *****************************
*
*
*  THIS OPERATION RUNS ON THE CALLING STACK
*
*      CALL UTIL
*      OPERATION
*      ERROR RETURN
*      NORMAL RETURN
*
*  THE CALLED OPERATION IS PASSED HL AND A
*
UTILTY SHLD XHL  SAVE HL
 STA XA  AND A
*
*  PICKUP THE OPERATION
*
 POP H
 MOV A,M
 INX H  MOVE RETURN PAST OPER
 PUSH H
 STA XOPER  SAVE OPERATION
*
*  REWIND THE FILE
*
 LDA UTIL
 MVI D,0
 CALL SYS  REWIND
 DB SPAOP
 JMP UER2
*
*  LOAD UTILITY FILE PREFIX
*
 LXI B,255  BC IS COUNT
 LXI H,CBUF  READ INTO CMD BUFFER
 XRA A  A IS ZERO
 MOV M,A  MAKE SURE A ZERO IS THERE
 XCHG .  DE IS DEST ADDRESS
*
 LDA UTIL  UTILITY FILE IS ALWAYS OPEN
 CALL SYS
 DB RBLOP  MEMORY PROTECT WILL SAY NO
 NOP
 NOP .  IGNORE
 NOP .  EOF
*
*  CHECK OPERATION
*
 LDA XOPER
 LXI H,CBUF
 CMP M  COMPARE TO MAX
 JNC UER1  ERROR, ITS TOO BIG
*
*  FIND OPERATION
*
 INX H  MOVE PAST MAX
 MOV C,A
 MVI B,0
 DAD B  + OPERATION
 DAD B
 MOV A,M
 INX H
 MOV H,M
 MOV L,A  = BRANCH ADDRESS
 ORA H
 JZ UER1  IT'S ZERO, FORGET IT
*
*  SETUP FOR CI IMAGE LOAD
*
 LDA UTIL
 STA CICNT  NOTE: B= 0 FROM ABOVE
 CALL SYS
 DB SEKOP
 JMP UER2
*
*  FINAL SETUP FOR CI LOAD IS DONE
*
 MVI A,1
 STA XQFLG  FORCE EXECUTION....BANG, BANG...SHOOT, STAB
 JMP CI75
*
*
*
UER1 MVI A,UTE0  BAD UTILITY OPERATION
UER2 RET .  JUST RETURN WITH SYS STUFF
*
*
*