PC Welt 1999 Hardware/PCWExtra.iso/sharewar/pcproble/CMOSSV.EXE/CMOS.ASM

Assembly Source File | 1997-07-08 | 21.1 KB | 936 lines

    PAGE    60,132
NAME    CMOSSAVE
    TITLE    CMOSSave Save CMOS to a file on disk or floppy
Comment |
    Version 3.0 by Roedy Green
    works with MASM 6.0 and Optasm
    This assembler code generates all three programs:
    CMOSSAVE.COM CMOSREST.COM and CMOSCHK.COM.

Note that we never compute or verify a checksum.  Every vendor computes
may compute it a slightly different way.

To come:
  /V:xx - additional volatile byte

See CMOS.TXT for details on use.

  USAGE:

Examples:
*********

CMOSSave A:\MyCMOS.Sav /Q

CMOSRest A:\MyCMOS.Sav /Q

CMOSChk  A:\ByCMOS.Sav /Q

Syntax errors or missing file trouble generates an ERRORLEVEL 4.
CMOSChk generates an ERRORLEVEL 1 if the CMOS has changed since
the CMOSSave was done.

Version History
***************

Version 1.0
- released to BIX 91/09/07

Version 1.1
- released to BIX 91/09/18
- added special check for small 64 character CMOSes.

Version 1.2
- fix spelling errors
- use CMOS.SAV instead of MyCMOS.SAV in examples

Version 1.3
- now consider fewer bytes volatile, restore more stuff.
- hints in docs about clearing CMOS.

Version 1.4
- now consider flags Status register C, offset 0C as volatile.
  fixes false alarms.

Version 1.5 1994 June 1
- change of address and phone number
- address now appears in the banner.

Version 1.6 1994 August 29
- more information about how CMOS bits are used.

Version 2.0 1994 October 1
- easier configuration of CHKCMOS volatile bytes.
- smarter bat files.
- docs on different ways to use.

Version 2.2 1995 April 16
- docs on use before experimentation

Version 2.3 1995 July 24
- add 3F as volatile byte.  PCI Pentiums are volatile.

Version 2.4 1995 August 7
- add /Q switch to suppress banners, only complain
- presume installation done to C:\CMP and that files saved there too.

Version 2.5 1996 January 27
- better documentation

Version 2.6 1996 June 3
- better documentation. Win 95 explanations.

Version 2.7 1996 August 19
- treat hex 3F differently in CMOSRest and CMOSChk

Version 2.8 1996 October  23
- POB in Quathiaski address.  Back to C:\SAFE as presumed directory
- lower cost $10, combined site licence.

Version 2.9 1996 November 22
- fix missing com files.

Version 3.0 1997 July 8
- notes on Y2K checking
- notes on separate rescue diskettes.

CMOS Usage - see also CMOS.OFS

How to Assemble
***************

Manually set the GENERATING equate embedded in this code, then:

to assemble with MASM 6.0 use:
ML.EXE /AT /c /Fl /VM /Zf /Zm CMOS.Asm
LINK.EXE /TINY /MAP CMOS.Obj,CMOS.com,CMOS.map;
copy cmos.com cmossave.com

to assemble with OPTASM use:
Optasm     CMOS.Asm,CMOS.Obj,CMOS.Lst/L/N/G/S
OLINK     CMOS.Obj,CMOS.COM,/MAP/TINY;
copy cmos.com cmossave.com

Register Conventions
********************

Subroutines may trash all registers except those explicity
documented as input or output.

| ; end of comment


;    E Q U A T E S

CMOSSAVE    EQU    1
CMOSREST    EQU    2
CMOSCHK     EQU    3

; use /DGenerating#CMOSSAVE
;     /DGenerating#CMOSREST
;     /DGenerating#CMOSCHK
; on the assembler command line to select which version
; of the code to assemble.
;    Or add code following of the form:

; GENERATING EQU CMOSSave


    If    Generating eq CMOSSave
%OUT Generating CMOSSave.Com
    Endif

    If    Generating eq CMOSRest
%OUT Generating CMOSRest.Com
    endif

    If    Generating eq CMOSChk
%OUT Generating CMOSChk.Com
    endif
;==============================================================


stack    segment stack        ; keep MS link happy by providing null stack
stack    ends

CODE    SEGMENT PARA        ; start off in code.

;==============================================================

data    segment byte        ; provide a separate DATA segment
                ; actually all come after the code
;==============================================================
;  V A R I A B L E S


    If    Generating eq CMOSSave

BannerMsg    label    byte
    DB    '░▒▓█ CMOSSave 3.0 █▓▒░',13d,10d
    DB    13d,10d
    DB    'Saves contents of CMOS to a file on hard disk or floppy.',13,10
    DB    'Copyright (c) 1991,1996 Roedy Green Canadian Mind Products.',13,10
    DB    'POB 707 Quathiaski Cove, Quadra Island, BC Canada V0P 1N0',13,10
    DB    'Telephone: [phone]          Internet:[e-mail]',13,10
    DB    'Shareware to freely distribute and use for any purpose except military.',13,10
    DB    13,10
    db    '$'

UsageMsg    DB '░▒▓█ Error █▓▒░',7,13,10
        DB 'Insert a formatted diskette.',13,10
        DB 'then try:',13,10
        DB 'CMOSSave A:\CMOS.Sav',13,10
        DB 'or if want to save on hard disk try:',13,10
        DB 'CMOSSave C:\SAFE\CMOS.Sav',13,10
        DB 'Read CMOS.TXT to find how to use it properly.',13,10
        db '$'

FileTroubleMsg    DB '░▒▓█ Error █▓▒░',7,13,10
        DB 'Cannot create the disk file.',13,10
        db '$'

WorkedMsg    DB 'CMOS successfully saved',13,10
        db '$'

    EndIf


    If    Generating eq CMOSRest
BannerMsg    label    byte
    DB    '░▒▓█ CMOSRest 3.0 █▓▒░',13d,10d
    DB    13d,10d
    DB    'Restores CMOS from a CMOSSave file on hard disk or floppy.',13,10
    DB    'Copyright (c) 1991,1996 Roedy Green Canadian Mind Products.',13,10
    DB    'POB 707 Quathiaski Cove, Quadra Island, BC Canada V0P 1N0',13,10
    DB    'Telephone: [phone]          Internet:[e-mail]',13,10
    DB    'Shareware to freely distribute and use for any purpose except military.',13,10
    DB    13,10
    db    '$'

UsageMsg    DB '░▒▓█ Error █▓▒░',13,10
        DB 'Insert the diskette you used for CMOSSave.',13,10
        DB 'then try:',13,10
        DB 'CMOSRest A:\CMOS.Sav',13,10
        DB 'or if the file is on hard disk try:',13,10
        DB 'CMOSRest C:\SAFE\CMOS.Sav',13,10
        DB 'Read CMOS.TXT to find how to use it properly.',13,10
        db '$'

FileTroubleMsg    DB '░▒▓█ Error █▓▒░',7,13,10
        DB 'Cannot find/read the disk file.',13,10
        db '$'

WorkedMsg    DB 'CMOS successfully restored',13,10
        db '$'

    EndIf

    If    Generating eq CMOSChk
BannerMsg    label    byte
    DB    '░▒▓█ CMOSChk 3.0 █▓▒░',13d,10d
    DB    13d,10d
    DB    'Ensures CMOS not corrupted or changed.',13,10
    DB    'Copyright (c) 1991,1996 Roedy Green Canadian Mind Products.',13,10
    DB    'POB 707 Quathiaski Cove, Quadra Island, BC Canada V0P 1N0',13,10
    DB    'Telephone: [phone]          Internet:[e-mail]',13,10
    DB    'Shareware to freely distribute and use for any purpose except military.',13,10
    DB    13,10
    db    '$'

UsageMsg    DB '░▒▓█ Error █▓▒░',7,13,10
        DB 'Insert the diskette you used for CMOSSave.',13,10
        DB 'then try:',13,10
        DB 'CMOSChk A:\CMOS.Sav',13,10
        DB 'or if you have the file on hard disk try:',13,10
        DB 'CMOSChk C:\SAFE\CMOS.Sav',13,10
        DB 'Read CMOS.TXT to find how to use it properly.',13,10
        db '$'

FileTroubleMsg    DB '░▒▓█ Error █▓▒░',7,13,10
        DB 'Cannot find/read the disk file.',13,10
        db '$'

MatchTroubleMsg DB '░▒▓█ Error █▓▒░',7,13,10
        DB 'CMOS has been corrupted! at hex offset:value:expected ',13,10
        db '$'

ColonMsg    db ':','$'

NextTripleMsg    db 13,10,'$'


WorkedMsg    DB 'CMOS is OK, i.e. unchanged since the last CMOSSave.',13,10
        db '$'

    EndIf

ParmIndex    DW    0


Filename    DB    64 dup (0)
            ; asciiz filename

SlashQuiet    DB    0
            ; -1 means quiet mode /Q

CMOSSize    DB    0
            ; size of cmos in bytes

CMOSBuff    db 0    ; dynamic buffer will grow to 128
            ; it hangs out past the end of the program

data        ends

com    group    code,data    ; force data segment to go at the end

    ASSUME    CS:com,DS:com,ES:com,SS:com
                ; seg regs cover everything
    ORG    100H        ; in Code segment

;==========================

Main    proc    far

;    M A I N L I N E   R O U T I N E
Start:
    Call    Parse        ; get filename and /Q from command line

    lea    dx,BannerMsg    ; display the banner if no /Q
    Call    SayQ

    If    Generating eq CMOSSave
    call    GetCMOS     ; fetch CMOS to buffer
    call    WriteCMOS    ; write CMOS contents to file
    lea    dx,WorkedMsg    ; crow about success
    Call    Say
    EndIf

    If    Generating eq CMOSRest
    call    ReadCMOS    ; read CMOS contents from file
    call    CalcCMOSSize    ; it is 64 or 128 bytes long?
    call    PutCMOS     ; store buffer to CMOS
    lea    dx,WorkedMsg    ; crow about success
    Call    Say
    EndIf

    If    Generating eq CMOSChk
    call    ReadCMOS    ; read CMOS contents from file
    call    CalcCMOSSize    ; it is 64 or 128 bytes long?
    call    CompareCMOS    ; compare CMOS with buffer
    lea    dx,WorkedMsg    ; crow about success
    Call    SayQ
    EndIf

Done:
    mov    ax,4c00h
    int    21h        ;normal termination

Main    EndP

;===============================================================

Trouble proc    near

FileTrouble:
    Lea    dx,FileTroubleMsg    ; display file trouble
    Call    Say
    Jmp    Abort

SyntaxTrouble:
    lea    dx,BannerMsg
    Call    Say
    LEA    dx,UsageMsg
    Call    Say
    Jmp    Abort

abort:
                ; error exit
    mov    ax, 4c04h    ; ERRORLEVEL = 4
    int    21h        ; DIE

Trouble endp

;===============================================================

SayQ    Proc
;    on entry DX points to a string to display
;    Only displays string if /Q not on
    test    SlashQuiet,-1
    jnz    Quietly
    call    Say
Quietly:
    ret
SayQ    Endp

;========================================

Say    Proc

;    on entry DX points to a string to display
    push    ax
    MOV    AH,9
    Int    21h
    pop    ax
    ret

Say    EndP

;======================================

    If    Generating eq CMOSSave

GetCMOS Proc    Near

;    Get 128 byte contents of CMOS into a buffer.

    mov    cx,128        ; count of times through loop
    lea    bx,CMOSBuff    ; where to put the contents
    sub    al,al        ; start offset in CMOS
GetLoop:
    Call    PeekCmos    ; al=offset ah=contents
    mov    byte ptr[bx],ah
    inc    al
    inc    bx
    loop    GetLoop
    ret

GetCMOS EndP

    EndIf

;===============================================================

    If    Generating eq CMOSRest

PutCMOS Proc    Near

;    Put 128-byte contents of buffer into CMOS.
;    do not touch the volatile bytes

    mov    cx,128        ; count of times through loop
    lea    bx,CMOSBuff    ; where to put the contents
    sub    al,al        ; start offset in CMOS
PutLoop:
    call    Volatile    ; test if this is a volatile byte
                ; test offset in al
    jc    LeaveItAlone
    mov    ah,byte ptr[bx]
    Call    PokeCMOS    ; al=offset ah=contents

LeaveItAlone:
    inc    bx
    inc    al
    loop    PutLoop
    ret

PutCMOS EndP

    EndIf

;===============================================================

    If    Generating eq CMOSChk

hexPAD    DB    '00$'    ; where numeric output built by SayHexByte

SayHexByte    proc    Near
    ;    al contains hex byte to display:

    push    ax        ; preserve regs
    push    bx
    push    cx
    push    dx
    mov    dl,al        ; save input
;    Do first (leftmost digit)
    mov    cl,4
    shr    al,cl
    and    al,0fh        ; get first digit
    cmp    al,9
    jg    HexChar1
    add    al,'0'        ; convert digit to ASCII
    jmp    StoreChar1
HexChar1:
    add    al,'A'-0AH    ; convert to uppercase A..H
StoreChar1:
    mov    hexPad,al

;    Do second (rightmost digit)
    mov    al,dl
    and    al,0fh        ; get last digit
    cmp    al,9
    jg    HexChar2
    add    al,'0'        ; convert digit to ASCII
    jmp    StoreChar2
HexChar2:
    add    al,'A'-0AH    ; convert to uppercase A..H
StoreChar2:
    mov    hexPad+1,al

;    Number is ready
    lea    dx,Hexpad
    mov    AH,09h        ; BIOS put string terminated by $
    int    21h
    pop    dx
    pop    cx
    pop    bx
    pop    ax
    ret

SayHexByte    ENDP

    EndIf

;===============================================================

    If    Generating eq CMOSChk
CompareCMOS    proc    Near

;    compares buffer version of CMOS with contents of actual CMOS
;    ignores mismatches of volatile bytes.
;    Aborts if finds a mismatch

    mov    cx,128        ; count of times through loop
    lea    bx,CMOSBuff    ; where to find comparison set
    sub    al,al        ; start offset in CMOS
    push    si
    sub    si,si        ; count of mismatches
CompLoop:
    call    Volatile    ; test if this is a volatile byte
                ; test offset in al
    jc    MatchedOk
    Call    PeekCMOS    ; al=offset ah=contents
    cmp    ah,byte ptr[bx] ; compare CMOS with buffer
    je    MatchedOk

;    Mismatch
    test    si,si            ; only complain on first mismatch
    jnz    AlreadyComplained
    lea    dx,MatchTroubleMsg    ; display CMOS mismatch
    call    Say
AlreadyComplained:
    push    ax
    inc    si        ; count of how many mismatches found
    Call    SayHexByte    ; report offset
    lea    dx,ColonMsg
    call    Say
    mov    al,ah        ; report bad value in CMOS
    Call    SayHexByte
    lea    dx,ColonMsg
    call    Say
    mov    al,byte ptr[bx] ; report what value should be from file.
    call    SayHexByte
    lea    dx,NextTripleMsg
    call    Say
    pop    ax

MatchedOk:
    inc    bx
    inc    al
    loop    CompLoop

    test    si,si
    jz    NoMismatches

    mov    ax, 4c01h        ; ERRORLEVEL = 1
    int    21h            ; DIE

NoMisMatches:
    pop    si
    ret

CompareCMOS    EndP

    EndIf

;===============================================================

    If    Generating ne CMOSSave

;    Add to this list if you need more volatile bytes.
;    Remember the trailing h.
;    Volatile bytes are not checked or restored.

;    0..09 are volatile
;    0ch is status byte
;    032h is century byte
;    03Fh is Pentium volatile byte


    if    Generating eq CMOSChk
VolatileList    db    0ch,032h,03Fh
;    see restore list below
    Endif

    if    Generating eq CMOSRest
VolatileList    db    0ch,032h
;    leave off 03Fh
    Endif

VolatileCount    equ    $-VolatileList


Volatile    Proc    near

;    Is cmos offset in AL volatile?    If so set carry.
;    These bytes will be undisturbed.
;    Preserves all registers.
;    00..09, 0C, 32 and 3F are volatile, rest are not.
;    0A 0B 0D 0E 0F used to be considered volatile, now are not.
;    if cmos is small, all bytes past end are considered volatile

    cmp    al,CMOSSize        ; bytes past end are volatile
    jae    IsVolatile
    cmp    al,09h
    jbe    IsVolatile        ; early bytes are for timing
    push    cx
    push    di
    mov    cx,VolatileCount
    lea    di,VolatileList
    repne    scasb            ; search till find a match
    pop    di
    pop    cx
    je    IsVolatile

IsNotVolatile:
    clc                ; clear carry
    ret

IsVolatile:
    stc
    ret

Volatile    EndP
    EndIf

;===============================================================

    If    Generating ne CMOSSave

CalcCMOSSize    Proc    near

;    Is CMOS 64 or 128 bytes long?
;    It is 64 if bytes at 10..2F match those at 50..6F.
;    Otherwise it is 128 bytes.
;    Preserves all registers.

    push    si
    push    di
    push    cx
    lea    si,CMOSBuff+10h
    lea    di,CMOSBuff+50h
    mov    cx,02fh+1-10h
    repe    cmpsb
    je    IsCMOS64

IsCMOS128:
    mov    CMOSSize,128    ; differ, must be a big CMOS
    jmp    CalcCMOSSizeDone

IsCMOS64:
    mov    CMOSSize,64    ; all same, small CMOS

CalcCMOSSizeDone:
    pop    cx
    pop    di
    pop    si

    ret

CalcCMOSSize    EndP
    EndIf

;===============================================================

    if    Generating ne CMOSRest

PeekCMOS    proc    near

;    Reads one byte from cmos.
;    on entry al has offset desired
;    on exit ah has the contents of that byte.
;    preserves all registers

;    See page 5-81 IBM AT Tech ref BIOS listing for how to read CMOS
;    We always enable the NMI with bit 7 on.

    push    bx
    push    ax
    cli                ; disable interrupts
    or    al,80h            ; disable NMI
                     ; controlled by port 70
    out    70h,al            ; output the byte address to CMOS
    jmp    $+2            ; delay, safer than nop
    in    al,71h            ; read the CMOS byte
    jmp    $+2            ; delay, safer than nop
    mov    bl,al
                    ; re-enable the NMI, high bit off
    mov    al,0dh            ; point to battery status register
    out    70h,al            ; leave pointing at a safe r/o register
    sti                ; restore interrupts
    pop    ax
    mov    ah,bl
    pop    bx
    ret

PeekCMOS    EndP

    EndIf

;===============================================================

    If    Generating eq CMOSRest

PokeCMOS    proc    near

;    Stuffs one byte into cmos.
;    on entry al has offset desired, ah has the value to stuff.
;    Preserves all registers.

;    See page 5-81 IBM AT Tech ref BIOS listing for how to write CMOS
;    We always enable the NMI with bit 7 on.

    push    ax
    cli                ; disable interrupts
    or    al,80h            ; disable NMI
    out    70h,al            ; output the byte address to CMOS
    jmp    $+2            ; delay, safer than nop

    mov    al,ah            ; get contents
    out    71h,al            ; poke the CMOS byte
    jmp    $+2            ; delay, safer than nop
                    ; re-enable the NMI
    mov    al,0dh            ; point to battery status register
    out    70h,al            ; leave pointing at a safe r/o register
    sti                ; restore interrupts
    pop    ax
    ret

PokeCMOS    EndP

    EndIf

;===============================================================

    If    Generating ne CMOSSave

ReadCMOS    Proc    Near

;    Open a file read the CMOS into a buffer

    lea    dx,FileName    ; DS:DX point to file
    xor    al,al        ; AL=0 is attribute read/only
    mov    ah,03Dh     ; DOS open function
    int    21h
    jc    FileTrouble
    mov    bx,ax        ; save handle
    mov    cx,128        ; read 128 bytes
    lea    dx,CMOSBuff    ; buffer address
    mov    ah,3fH        ; DOS read
    int    21h
    jc    FileTrouble
    cmp    ax,128
    jne    FileTrouble
    mov    ah,3eh        ; DOS close
    int    21h
    jc    FileTrouble
    ret

ReadCMOS    EndP

    EndIf

;===============================================================

    if    Generating eq CMOSSave

WriteCMOS    Proc    Near

;    Create a file; write CMOS to it

    lea    dx,FileName    ; DS:DX point to file
    xor    cx,cx        ; CX=0 is attribute
    mov    ah,03ch     ; DOS create function
    int    21h
    jc    FileTrouble
    mov    bx,ax        ; SAVE HANDLE
    MOV    CX,128        ; write 128 bytes
    lea    dx,CMOSBuff    ; buffer address
    mov    ah,40h        ; DOS write
    int    21h
    jc    FileTrouble
    cmp    ax,128
    jne    FileTrouble
    mov    ah,3eh        ; DOS close
    int    21h
    jc    FileTrouble
    ret

WriteCMOS    EndP

    EndIf

;===============================================================

Parse    Proc    near
;    Parse the command line and process each parameter.
;    sample inputs
;    CMOSSAVE A:\CMOS.SAV /Q
;    CMOSREST C:\CMP\CMOS.SAV
                ; counted string at HEX 80 PSP
                ; contains command line.
                ; Preceeded by unwanted spaces.
                ; possibly followed by unwanted spaces.
                ; currently missing a trailing null.
                ; Both ES and DS cover the command line
                ; since this is a COM file.
                ; However to make code compatible with EXE
                ; files we use ES: to cover the command line.
    call    CommandLine    ; string addr ES:bx, length cx.
    jcxz    NullParms

    mov    ParmIndex,1    ; start parsing with the 1st parm
                ; note start with 1 not 0!
                ; We don't want the the program name.
    jmp    Short Parseloop

NullParms:
NoMoreParms:
    test    fileName,-1    ; ensure some sort of filename provided
    jz    BadCmd        ; by the time all done
    mov    ax,DS
    mov    ES,ax        ; restore ES to match DS
    ret            ; we are done

Parseloop:
    call    CommandLine    ; commmandline=ES:bx, length=cx
    mov    dx,ParmIndex
    call    NthParm     ; work left to right
    jcxz    NoMoreParms    ; null param means no more
                ; e.g. ES:bx points to A: or /Q
                ; cx is length of that piece
    mov    ax,ES:[bx]    ; al=A ah=:  or  al=/ ah=Q
    call    ToUc        ; Convert both chars to upper case
    xchg    ah,al
    call    ToUc
    cmp    ah,'/'        ; drive or Switch?
    jne    ProcessDrive
                ; it was a switch with slash
                ; was it /Q?
    cmp    al,'Q'
    JE    ProcessQ
                ; something else, give up.
BadCmd:
    jmp    SyntaxTrouble

ProcessDrive:
                ; don't insist on drive letter.
                ; should have C:\CMP\CMOS.SAV
                ; copy string to FileName
                ; followed by a null

    mov    si,bx
    lea    di,FileName    ; ES:si -> DS:di ( segs are backwards )
    push    ES        ; swap ES DS
    push    DS
    pop    ES
    pop    DS
    rep movsb        ; copy filename DS:si -> ES:di
    mov    ES:[di],byte ptr 0 ; append a null
    push    ES        ; swap ES DS back to normal
    push    DS
    pop    ES
    pop    DS
    jmp    short Next

ProcessQ:            ; handle /Quiet
    mov    SlashQuiet,-1

Next:
    inc    ParmIndex    ; bump loop counter
    jmp    Parseloop    ; loop till hit null param

Parse    EndP

;===============================================================

CommandLine Proc  near
;    gets command line into ES:bx with length in cx.
;    This version works for a COM file only.
    xor    ch,ch
    mov    cl,ES:80H
    mov    bx,81H
    ret
CommandLine EndP

;===============================================================
NthParm Proc    near
;    Parses string for Nth Parameter delimited by blanks
;    e.g.  "  A: /Q " with bx=1 would give string "/Q"
;    on entry:
;    ES:bx - string, usually the command line
;    cx - length of string
;    dx - which parm wanted 1=parm1 2=parm2 etc.
;    NthParm only finds one parm per call.
;    On exit ES:bx points to string and cx is its length.
;    If there is no parm, the length will be 0.
;    It also handles multiple leading/trailing blanks on parms.
    mov    al,20h        ; al = blank  -- the search char
    mov    di,bx
Parmloop:
;    Remove leading blanks on parm
    jcxz    NullParm    ; jump if null string
    repe    scasb        ; scan ES:di forwards till hit non blank

                ; di points just after it
                ; cx is one too small, or 0 if none found
    je    NullParm    ; jump if entire string was blank
    inc    cx        ; cx is length of remainder of string
    dec    di        ; di points to non-blank
    mov    si,di        ; remember start of string
;    Search for terminating blank on parm
    jcxz    NullParm    ; jump if null string
    repne    scasb        ; scan ES:di forwards till hit blank
                ; di points just after it
                ; cx is one too small, or 0 if none found
    jne    NoBlank     ; jump if entire string was non blank
    inc    cx        ; cx is length of remainder of string
    dec    di        ; backup di to point to blank at string end
NoBlank:
                ; di=addr tail end of command string,
                ; cx=len tail end of command string
                ; si=addr parm just parsed
;    Major loop for each parm
    dec    dx
    jnz    Parmloop    ; loop once for each parm

    mov    cx,di
    sub    cx,si        ; cx is length of parameter.
    mov    bx,si
    ret
NullParm:            ; was no nth parameter
    mov    cx,0
    mov    bx,si
    ret
NthParm EndP

;==============================================================

ToUC        PROC    NEAR
;    converts char in AL to upper case
    cmp    al,'a'
    jb    FineAsIs
    cmp    al,'z'
    ja    FineAsIs
    sub    al,20H        ; convert a to A
FineAsIs:
    ret

ToUc        ENDP

;======================================

;===============================================================

CODE    ends            ; end of code segment
    end    Start