CP/M/CPM_CDROM.iso/cpm/rcpm/userpw37.asm

Assembly Source File | 1994-07-13 | 20.3 KB | 681 lines

;
;    USERPW.ASM  version 3.7   10/05/82
;      By Dave Hardy
;
;
;    USERPW is used to replace the 'USER' command in a remote
;    CP/M system, which is usually removed to restrict users
;    to the lower user areas. USERPW will allow password access
;    to any group of user areas via any number of passwords
;    that are specified in an external file called PWFILE.
;    An option is also available that allows only a single
;    built-in password to be used, as in the original version.
;    Public access is available to all user areas with values less
;    than MAXUSER (set below), and USERPW will also allow password
;    access to the 'restricted' user areas.  If the caller
;    types only the filename, with no user number on the command
;    tail, the program will tell the caller what user number he
;    is in and give instructions.
;
;   If the PWFILE option is selected, then the entered password will
;    be compared with a disk-resident file called PWFILE kept in a
;    user area specified by the PWUSR equate.  Each line of PWFILE
;    contains one password, followed by each allowed user area, all
;    separated by commas.  The last line of the file must contain
;    a '$' to indicate the end-of-file.  In addition, a semicolon
;    (';') may be used to indicate that the rest of any line is to
;    be ignored, and treated as a comment.  This feature may be used with
;    the CHGPW.ASM program to allow users to change their own passwords,
;    or just as a convenient way to leave comments in the PW file.
;
;PWFILE STRUCTURE IS:    PASSWORD1,X,Y<cr><lf>    <--X and Y are USER #'s
;            PASSWORD2,Y<cr><lf>
;            PASSWORD3,X,Y;JOHN SMITH<--this is a comment
;            etc....
;            $            <--this must be here
;
;  Modification history:
;10/05/82 Added code to allow PW to be echoed to the local console
;      as it is printed.  This uses direct console I/O which must
;      be modified to match your system.  The status of the output
;      port is not checked, since the console ALWAYS runs faster
;      than the modem.  See the PWCON equate below.
;      By Dave Hardy
;
;08/23/82 Added comment option to PWFILE to allow comments, and to work
;      with CHGPW.ASM to allow users to change their passwords.
;      Repaired bugs in optional drive select routines that caused
;      PWFILE to be trashed if both DRIVE and PWFILE are TRUE, and
;      modified LODPWF to prevent PWFILE from overlaying the CCP.
;      However, there are still problems in the code that prevent the
;      program from working when BOTH DRIVE and PWFILE are TRUE.
;     (Therefore, the DRIVE option only works when the PWFILE option
;      is false.  In order to modify this program to work with DRIVE
;      and PWFILE at the same time, I would have to entirely restructure
;      the PWFILE itself.  Also, the PWFILE would become extremely large.
;      If enough interest is shown, I will modify this program (and
;      CHGPW.ASM) to work with this selection method (USER <drive><user>),
;      but I prefer to keep the syntax used with this program the same as
;      that used by DR's CCP (USER <user>), since this program is intended
;      to be an upward compatible replacement for the CCP's USER function.)
;      Changed defaults to conform with standard CP/M.
;      By Dave Hardy
;
;06/04/82 Added optional drive select to command line. If DRIVE
;      is TRUE then the command line should contain both drive
;      and user area desired. Ex: USER B4 will select drive B,
;      user area 4.  Added necessary code to allow drive
;      logging.  MAXDRV should be set to the maximum drive allowed.
;      Ex: A=1, B=2, etc.  Added offset capability with BASE
;      definition.
;      By Howard Booker
;
;11/03/81 Removed BACKSPACE and DELETE code to prevent nightmare
;      bug that allowed remote callers to backspace over code
;      and cause PWFILE to be printed as part of "INCORRECT"
;      error messages.
;      By Dave Hardy
;
;08/24/81 Cleaned up file, made compatible with MAC/ASM, made lower
;      case trap conditional (since some PW's might want them,
;      or numbers, etc.), changed PW error jump to eliminate
;      reloading PWFILE, corrected errors in BADPW routine,
;      and separated GOCCP code to avoid confusion.
;      By Dave Hardy
;
;08/23/81 Added multiple tries at PW, Trap for lower case,
;         cleaned up code and added many needed C/R's & L/F's.
;         By Jim C., Larkspur, Ca. RCPM [phone]
;
;08/19/81 Added equates for use with the GOCCP program.
;         By Larry Shipinski
;
;08/18/81 Moved PWFILE loader CALL so that PWFILE will be loaded
;      before asking for PW, to eliminate the noticeable delay
;      before warm-boot, cleaned up code, and added comments.
;      By Dave Hardy
;
;08/11/81 Added RANGE conditional to allow PW access to a range of
;      user areas.  For example, if the range is from 1 to 4, then
;      once a user has logged into any user area within the range,
;      he may log into any other user areas within the range without
;      having to re-enter the password.  This is similar to the
;      LOGONCE option, but allows any range of user numbers to be
;      selected, while the range of LOGONCE includes all non-zero
;      user areas.  In addition, RANGE can only be used if the
;      PWFILE conditional is selected, and LOGONCE can only be
;      used if the PWFILE conditional is NOT selected.
;      By Dave Hardy
;
;08/09/81 Added PWFILE conditional to allow multiple passwords to be
;      readfrom a file, so that separate PW's can be used for
;      different user areas.  The number of PW's will be limited
;      only by the amount of available memory in the TPA.
;      The file of passwords can be kept in any user area,
;      and can be created with any editor.  Multiple user areas
;      are available to each password.  The format of the PWFILE
;      is defined at the beginning of this file.
;      By Dave Hardy
;
;08/03/81 Changed console input routines to DIRECT I/O so that
;      password will not be echoed.  This should make the
;      program's function a bit more secure by making it more
;      difficult to see what password has been typed.
;      By Dave Hardy
;
;07/12/81 Added TELUSR routines to inform caller of current user
;      number and how to use program.  Changed version number
;      to 2.1 instead of 3.0, because I'm still working on a
;      major revision of USERPW to be released as version 3.0.
;      By Dave Hardy
;
;05/23/81 Added LOGONCE option so that program will not ask for PW
;      if user is already in password-accessible user area.
;      By Dave Hardy
;
;  Define miscellaneous values:
SETUSR    EQU    32    ;BDOS Set User function
PRNSTR    EQU    9    ;BDOS Print String function
OPEN    EQU    15    ;BDOS Open File function
CURDSK    EQU    25    ;BDOS Return Current Disk function
STDMA    EQU    26    ;BDOS Set DMA Address function
READ    EQU    20    ;BDOS Read Sequential function
CONOUT    EQU    2    ;BDOS Print Character function
DIRIO    EQU    6    ;BDOS Direct Console I/O function
BASE    EQU    0    ;SET TO BASE ADDRESS OF YOUR SYSTEM
USERDR    EQU    BASE+4    ;CP/M's USER/DRIVE select byte
WBOOT    EQU    BASE    ;CP/M's warm-boot address
BDOS    EQU    BASE+5    ;CP/M'S BDOS JUMP vector
DFCB    EQU    BASE+5CH ;Default File Control Block address
SELDSK    EQU    18H    ;SELDSK vector offset from BIOS's warm-boot vector
INPUT    EQU    0FFH    ;Value passed to DIRIO to cause console input
CR    EQU    0DH    ;ASCII carriage-return
LF    EQU    0AH    ;ASCII line-feed
;
;  Define TRUE and FALSE:
FALSE    EQU    0
TRUE    EQU    NOT FALSE
;
;
;  Set the following equates as desired:
;
; ***NOTE: DRIVE AND PWFILE CANNOT BE TRUE AT SAME TIME***
MAXUSER EQU    0    ;Set to highest PUBLIC user area desired
ABSUSER    EQU    15    ;Set to highest PW ACCESS user area desired
MAXTRYS    EQU    3    ;Max # of PW attempts before exit to CP/M
DRIVE    EQU    FALSE    ;True, if using both drive and user command line
MAXDRV    EQU    2    ;Set to max # drives to avoid sel. err. if DRIVE TRUE
PWFILE    EQU    TRUE    ;True, if PW's from file instead of built-in
PWUSR    EQU    21    ;User area where PWFILE is to be kept
PWDRV    EQU    1    ;Drive where PWFILE is kept (1=A, 2=B, etc.)
PWCON    EQU    TRUE    ;True, if want PW echoed locally as it is typed
LOCCON    EQU    81H    ;Local console output port (if PWCON=TRUE)
TRAPLC    EQU    TRUE    ;True, if want to only use upper-case PW's
RANGE    EQU    TRUE    ;True, if no ask for PW when within ranges
HRANGE    EQU    4    ;High-end value of "no ask" range
LRANGE    EQU    1    ;Low-end value of "no-ask" range
LOGONCE    EQU    FALSE    ;True, if desire log-in only from user 0
            ;LOGONCE SHOULD BE FALSE if PWFILE is used
;
;  The following code is for use with the GOCCP program, which
;  is a CCP substitute.  If you are not using GOCCP, then setting
;  GOCCP to TRUE will cause unpredictable results.  NOTE that this
;  option requires that you set the label CCP equal to the address
;  of the CCP in your system.  This address can be determined most
;  easily by using the STATUS or BDLOC programs.
;
GOCCP    EQU    FALSE    ;True, if using the GOCCP program
    IF    GOCCP
CCP    EQU    BASE+3400H    ;Set to start of CCP in your system
REQUSR    EQU    CCP+7FEH    ;Store requested USER number in CCP
    ENDIF
;
; Start of USERPW code
;
    ORG    BASE+100H
;
    XRA    A        ;Initialize first pass flag
    STA    FLAG
;
    LXI    H,DFCB+1 ;Point to specified USER # in command line
    MOV    A,M    ;Check that there is something in command line
    CPI    20H
    JZ    TELUSR    ;Nothing?  then tell user number and give help
;
    IF    DRIVE    ;Select drive option
    LDA    USERDR    ;Get current drive
    STA    CURDRV    ;And save it
    MOV    A,M
    SUI    'A'    ;Remove ASCII bias
    CPI    MAXDRV
    JNC    NOBODY
    STA    USERDR
    MOV    C,A
    PUSH    H
    LHLD    WBOOT+1    ;Get BIOS vector
    LXI    D,SELDSK
    DAD    D    ;Compute SELDSK adr
    SHLD    SAVSEL    ;Save it
    LXI    D,VECRET
    PUSH    D
    MVI    E,1    ;Dont log yet (for speed)
    PCHL
VECRET    POP    H    ;Continue..
    INX    H
    ENDIF        ;DRIVE
;
    MVI    E,0    ;Initialize user number accumulator
NUMLUP    MOV    A,M    ;Get first character
    INX    H    ;Point to next location in command line
    SUI    '0'    ;Remove ASCII bias
    JC    NUMDONE    ;Exit with specified user number in E
    CPI    10    ;Check for illegal number (>9)
    JNC    NUMDONE    ;Stop if illegal character found
    MOV    D,A    ;Get specified user number
    MOV    A,E    ; into A register
    ADD    A
    ADD    A
    ADD    E
    ADD    A
    ADD    D
    MOV    E,A    ;Save accumulation
    JMP    NUMLUP    ;Loop back for next character
;
TELUSR    LXI    D,TUMSG    ;Tell the user what user number he's in
    MVI    C,PRNSTR
    CALL    BDOS
    LDA    USERDR    ;Get current USER number
    RRC
    RRC
    RRC
    RRC
    ANI    0FH
    CPI    0AH
    JC    LT10
    PUSH    PSW    ;Save user number
    MVI    E,'1'    ;If user # is 10-16, then print leading '1'
    MVI    C,CONOUT    ;This routine won't work
    CALL    BDOS        ;if your CCP allows more than 19 user areas.
    POP    PSW    ;Restore user number
    SUI    0AH
LT10    ADI    30H    ;Print user number
    MOV    E,A
    MVI    C,CONOUT
    CALL    BDOS
    MVI    E,'.'    ;End the line with a period
    MVI    C,CONOUT
    CALL    BDOS
;
    CALL    ERRXIT    ;Print rest of message, then exit to CP/M
    DB    CR,LF,'To change user areas, type '
;
    IF    DRIVE
    DB    'drive letter and '
    ENDIF
;
    DB    'user number on command line.',CR,LF
    DB    'For example, type: USER '
;
    IF    DRIVE
    DB    'B'
    ENDIF
;
    DB    '3   to enter '
;
    IF    DRIVE
    DB    'Drive B, '
    ENDIF
;
    DB    'user area 3.',CR,LF,'$'
;
NUMDONE    MOV    A,E    ;Get requested user number
    STA    REQUSR    ;Save for later, if needed
    ORA    A
    RM        ;Exit if illegal user number
    CPI    ABSUSER+1
    JNC    NOBODY    ;Illegal user area request
    CPI    MAXUSER+1
    JNC    SOME    ;Password user area request
CHANGE    RLC        ;Move to upper nibble
     RLC
     RLC
     RLC
    MOV    B,A    ;Save requested user number
    LDA    USERDR    ;Get current user/drive number
    ANI    0FH    ;Trim off old user number
    ORA    B    ;Add new user number
    STA    USERDR    ;Set new user number
    LDA    REQUSR
    MOV    E,A
    MVI    C,SETUSR ;Set user number with BDOS call, too.
;
    IF    DRIVE
    CALL    BDOS
    JMP    WBOOT
    ENDIF
;
    JMP    BDOS     ;  then exit
;
;
;  REQUEST FOR RESTRICTED USER AREA, SO ASK FOR PASSWORD
;
SOME    EQU    $
;
    IF    LOGONCE    ;then see if user has already logged in
    LDA    USERDR    ;Get USER NUMBER/DRIVE
    ANI    0F0H
    RLC
    RLC
    RLC
    RLC
    MVI    B,MAXUSER+1
    CMP    B
    JNC    GOTPW    ;If in non-public user area, PW was already
            ; given so don't ask again
    ENDIF
;
    IF    PWFILE AND RANGE    ;Then check for already in RANGE
    LDA    USERDR            ;Get USER/DRIVE number
    ANI    0F0H
    RLC
    RLC
    RLC
    RLC
    MVI    B,HRANGE+1        ;See if above RANGE
    CMP    B
    JNC    PRANGE            ;Jump if above RANGE
    MVI    B,LRANGE        ;See if below RANGE
    CMP    B
    JC    PRANGE            ;Jump if below RANGE
    LDA    REQUSR    ;Now see if requested user# is in RANGE
    MVI    B,HRANGE+1        ;See if above RANGE
    CMP    B
    JNC    PRANGE            ;Jump if above RANGE
    MVI    B,LRANGE        ;See if below RANGE
    CMP    B
    JC    PRANGE            ;Jump if below RANGE
    JMP    GOTPW    ;If already in RANGE, and new user # is also in
    ENDIF        ; RANGE, then don't ask for PW
;
PRANGE    EQU    $
;
    IF    PWFILE
    CALL    LODPWF    ;Load the file of PW's
    ENDIF
;
PR2    LDA    FLAG    ;Get # of passes
    ORA    A    ;First pass?
    JZ    NOCRLF    ;If yes, then no CRLF needed
    LXI    D,CRLF    ;Else print a CRLF to put next PW on a new line
    MVI    C,PRNSTR
    CALL    BDOS    ;Print CRLF
NOCRLF    LXI    D,MSG    ;Ask for password
    MVI    C,PRNSTR
    CALL    BDOS
;
    LXI    H,CONBUF    ;Reset console buffer pointer
    MVI    C,10H        ;Allow 16 characters maximum
TRYAGN    PUSH    B
    PUSH    H
    MVI    C,06H    ;Direct console I/O
    MVI    E,0FFH    ;Console input
    CALL    BDOS    ;Get password, 1 character at a time
    POP    H
    POP    B
    ORA    A    ;Wait for input
    JZ    TRYAGN
;
    IF    TRAPLC
    CPI    060H    ;Lower Case?
    JC    NOTLC    ;No, Skip.
    ANI    05FH    ;Strip L/C.
    ENDIF
;
NOTLC    CPI    0DH    ;Carriage return?
    JZ    CHKPW    ;If yes, then check for match
;
    IF    PWCON    ;Then echo the character to the local console
    OUT    LOCCON    ;(NOTE that NO status checking is necessary)
    ENDIF
;
    MOV    M,A    ;Put character into buffer
    INX    H    ;Increment pointer
    DCR    C    ;See if 16 characters entered
    MOV    A,C
    ORA    A
    JNZ    TRYAGN        ;If less than 16 characters entered,
                ;then continue...
;
    IF    NOT PWFILE    ;Then check built-in PW
CHKPW    LXI    H,CONBUF    ;Check for match with password
    LXI    D,PASSWD    ;Point DE and HL to buffers
NEXT    LDAX    D
    CPI    '$'        ;When '$' found, then passwords match,
    JZ    GOTPW        ;  so jump
    CMP    M        ;Else check for character match
    JNZ    BADPW        ;Jump if wrong password given
    INX    H        ;Check next character for match
    INX    D
    JMP    NEXT
    ENDIF
;
    IF    PWFILE        ;Then check list of PW's in PWFILE
CHKPW    LHLD    LASTPW
    XCHG            ;Make DE point to first PW in file
    JMP    FRSTPW        ; Then check for match
DONXPW    CALL    GETNXPW        ;Returns with DE==>PW or '$' in PWFILE
FRSTPW    LDAX    D        ;If DE==>'$' then done, no match
    CPI    '$'
    JZ    BADPW        ;Jump if wrong PW given
    LXI    H,CONBUF    ;Point HL to entered password
NEXT    LDAX    D
    CMP    M        ;Else check for character match
    JNZ    DONXPW        ;If no match, then try next PW
    INX    H        ;Else try next character for match
    INX    D
    LDAX    D
    CPI    ','        ;If ',' found, then passwords may match
    JNZ    NEXT        ; If not found, then continue,
    MOV    A,M        ;Else check that both PW's are all read
    CPI    0
    JZ    CHKUSR        ;If both completely read, then match, so jump
    JMP    DONXPW        ;Else try next PW in PWFILE list
;
GETNXPW    LHLD    LASTPW        ;Get pointer to last PW checked
NXCH    MOV    A,M
    CPI    0DH        ;Scan for carriage return
    JZ    GOTCR        ;When CR found, then point to next PW
    CPI    '$'        ;Check for '$' here just in case...
    JZ    NOMORE        ;If '$' found, then no more PW's
    INX    H
    JMP    NXCH
;
GOTCR    INX    H        ;Skip over LF
    INX    H        ;And point to next PW
    SHLD    LASTPW        ;Save pointer to current PW
NOMORE    XCHG            ;MAKE DE==>PW or '$'
    RET            ;Then return to calling routine
;
CHKUSR    XCHG        ;Make HL==>first user number in PWFILE line
    INX    H
NXNUM    MVI    E,0    ;Initialize USER number accumulator
NUMLUP2    MOV    A,M    ;Get first character
    INX    H    ;Point to next location in command line
    SUI    '0'    ;Remove ASCII bias
    JC    CMPUSR    ;Exit with specified user number in A
    CPI    10    ;Check for illegal number (>9)
    JNC    CMPUSR    ;Stop if illegal character found
    MOV    D,A    ;Get specified user number
    MOV    A,E    ; into A register
    ADD    A
    ADD    A
    ADD    E
    ADD    A
    ADD    D
    MOV    E,A    ;Save accumulation
    JMP    NUMLUP2    ;Loop back for next character
;
CMPUSR    DCX    H    ;Back up pointer (NUMLUP2 advanced 1 too many)
    LDA    REQUSR    ;Compare allowable user# to the requested one.
    CMP    E
    JZ    GOTPW    ;Jump if they match, change user #, then exit
    MOV    A,M    ;Check for CR, which means no more user areas
    CPI    0DH    ;Jump if no more, and say "denied"
    JZ    NOBODY2
    INX    H    ;Skip over ',' and point to next user number
    MOV    A,M    ;Check for CR, which means no more user areas
    CPI    0DH    ;Jump if no more, and say "denied"
    JZ    NOBODY2
    CPI    ';'    ;If comments found, then treat same as CR found
    JZ    NOBODY2
    JMP    NXNUM    ;Try next user number in PWFILE line
    ENDIF
;
GOTPW    LDA    REQUSR        ;Get back requested user number
    JMP    CHANGE        ;Change user number and exit
;
BADPW    MVI    C,PRNSTR    ;Print "BAD PASSWORD" message
    LXI    D,BADMSG
    CALL    BDOS
;
    IF    PWFILE    ;Then initialize CONBUF and PW pointer
    CALL    INIT
    ENDIF
;
    IF    NOT PWFILE    ;Then just initialize CONBUF
    LXI    H,CONBUF
    MVI    C,17
NXIN    MVI    M,0
    INX    H
    DCR    C
    JNZ    NXIN
    ENDIF
;
    LDA    FLAG        ;Get # of trys flag
    INR    A        ;Increment # of trys.
    STA    FLAG
    CPI    MAXTRYS        ;See if max guesses...
    JC    PR2        ;If more tries allowed, then jump
;
NOBODY2    LXI    D,CRLF    ;Print 'NO ACCESS' msg on new line, then exit to CP/M
    MVI    C,PRNSTR
    CALL    BDOS
;
NOBODY    CALL    ERRXIT    ;Print 'NO ACCESS' message, then exit to CP/M
    DB    'Sorry, that '
;
    IF    DRIVE
    DB    'drive/'
    ENDIF
;
    DB    'user area is not available.','$'
;
;    Routine to load the password file
    IF    PWFILE
LODPWF    MVI    E,PWUSR
    MVI    C,SETUSR
    CALL    BDOS    ;Set to whatever user number that PWFILE is in
    MVI    A,PWDRV    ;Initialize FCB for selected drive
    STA    LOCFCB
    LXI    H,LOCFCB+12
    MVI    B,21
ZLOOP    MVI    M,0
    INX    H
    DCR    B
    JNZ    ZLOOP
    MVI    C,OPEN    ;Open the file
    LXI    D,LOCFCB
    CALL    BDOS
    INR    A
    JZ    ABORT    ;If A has 0 then no file, so abort
;
;    Now load the file
;
    LHLD    6    ;Check for attempt to load past top of TPA
    LXI    D,-880H    ;Calculate BDOS - 800H (=CCP) - 80H
    DAD    D
    PUSH    H    ;Save top of memory for later checks
;
    LXI    D,PWBUF-80H    ;Point to file load area-80H
    LXI    B,0    ;Initialize record counter
    PUSH    B    ; and save it
    PUSH    D    ;Save load address, too
GLOOP    POP    D    ;Get last load address
    LXI    H,80H    ;Point HL to next address to read to
    DAD    D
    POP    B    ;Increment the record counter
;
;    Check for attempt to load past top-of-memory
;
    POP    D    ;Get -(TOP-OF-MEMORY)
    PUSH    D    ;Save again for next time
;
    MOV    A,E    ;Subtract: (TOP) - (ADRS)
    SUB    L
    MOV    A,D    ;Look at carry to see if out of memory
    SBB    H
;
    JNC    SIZEOK    ;Jump if enough room
    CALL    ERRXIT    ; Else print message and abort
    DB    '+++DATA AREA TOO SMALL FOR PWFILE','$'
;
SIZEOK    INX    B    ;Continue loading...
    PUSH    B
    PUSH    H    ;Save load address
    XCHG
    MVI    C,STDMA ;Set DMA address for next read
    CALL    BDOS
    LXI    D,LOCFCB ;Then read the next sector
    MVI    C,READ
    CALL    BDOS
    ORA    A
    JZ    GLOOP    ;If A=0 then more to read
    POP    B
    POP    B    ;Restore record counter
    POP    H
    MOV    A,B
    ORA    C
    JZ    ABORT    ;If 0 then nothing read, so abort
    LXI    D,80H    ;Else, reset DMA address
    MVI    C,STDMA
    CALL    BDOS
INIT    LXI    H,CONBUF    ;Initialize console input buffer
    MVI    C,17
NXINIT    MVI    M,0
    INX    H
    DCR    C
    JNZ    NXINIT
    LXI    H,PWBUF
    SHLD    LASTPW    ;Save pointer to first PW in file
    RET        ; and return
;
ABORT    CALL    ERRXIT
    DB    '+++CANNOT FIND PW FILE, ACCESS DENIED','$'
    ENDIF
;
ERRXIT    POP    D
    MVI    C,PRNSTR
    CALL    BDOS    ;PRINT THE ABORT MSG, THEN EXIT
;
    IF    DRIVE
    LDA    CURDRV    ;Return to original drive/user
    STA    USERDR
    ANI    0FH
    MOV    C,A
    LHLD    SAVSEL
    LXI    D,WBOOT
    PUSH    D
    MVI    E,1
    PCHL
    ENDIF        ;DRIVE
;
    JMP    WBOOT
;
;
;  Some miscellaneous messages:
;
MSG    DB    'PW=','$'    ;Msg to ask user for pw
;
BADMSG    DB    '+++INCORRECT','$'
;
TUMSG    DB    'You are in USER area $'    ;First part of help msg.
;
CRLF    DB    CR,LF,'$'    ;Printed to start a new line
;
;
    IF    NOT GOCCP;Then save user number here in TPA
REQUSR    DB    00H    ;Temporary storage area for user area number
    ENDIF
;
FLAG    DB    0    ;Counter for multiple PW attempts
;
    IF    DRIVE    ;Then need a place to store these
CURDRV    DB    0    ;Storage area for current drive
SAVSEL    DW    0    ;Storage area for SELDSK address
    ENDIF
;
;
;  CONSOLE INPUT BUFFER, USED FOR PASSWORD INPUT
;
CONBUF    DB    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
        ;Up to 16 characters for password
;
    IF    NOT PWFILE
;  PASSWORD TO ALLOW 'RESTRICTED USER AREA' ACCESS GOES HERE
PASSWD    DB    'PASSWORD','$'    ;Must be followed by '$'
    ENDIF
;
    IF    PWFILE
LOCFCB    DB    0    ;Drive is filled in here
    DB    'PWFILE     '    ;Name of file that contains PW's
    DS    40H    ;Some more room+ for PWFILE
;
LASTPW    DW    0000H    ;Pointer to current PW in PWFILE
;
;  PWFILE is read in starting here.  It can take up the entire TPA
;    if desired.  The CCP is not overlayed.
PWBUF    EQU    $    ;Rest of TPA is available for PWFILE
    ENDIF
;
    END