From: "J.A. Bijsterbosch" <bijster AT worldonline DOT nl>
Newsgroups: comp.os.msdos.djgpp
Subject: Syntax differences between TASM and NASM
Date: 29 Oct 1997 18:08:20 GMT
Organization: Bijsterbosch Productions
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To: djgpp AT delorie DOT com
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Hello All,

After some years in C/C++ programming and a quote in mind of Michael
Abrash that "the best optimiser is between the ears" <g>, I found it time
to start learning a little bit assembler as well.
I found a nice book that starts from zero knowledge by Peter Norton & John
Socha about this subject, but it uses MASM and/or TASM as assembler.
Because I don't want to spend money immediately, I thought of using NASM,
however some derictives used in the book are not recognised by this last
one.
I have been digging through nasm.doc to see if there where replacements for
these, and found some solutions with which the revised code compiles
alright, but
since I'm a total newbie in assembler and it's terminology still, It would
be nice if someone could tell whether the two following code snippets
evolve
to the same result and functionality.

TASM code:

PUBLIC		WRITE_HEX_DIGIT

WRITE_HEX_DIGIT	PROC
        PUSH    DX                  		; Save registers used
        CMP     DL,10               		; Is this nibble <10?
        JAE     .HEX_LETTER         	; No, convert to a letter
        ADD     DL,"0"              		; Yes, convert to a digit
        JMP     Short WRITE_DIGIT  	; Now write this character
HEX_LETTER:
        ADD     DL,"A"-10           		; Convert to hex letter
WRITE_DIGIT:
        CALL    WRITE_CHAR          	; Display letter on screen
        POP     DX                  		; Restore old value of DX
        RET
WRITE_HEX_DIGIT	ENDP

NASM code:

[ORG 0x100]				; for creating .com file direct

[GLOBAL WRITE_HEX_DIGIT]

WRITE_HEX_DIGIT:
        PUSH    DX                  		; Save registers used
        CMP     DL,10               		; Is this nibble <10?
        JAE     .HEX_LETTER         	; No, convert to a letter
        ADD     DL,"0"              		; Yes, convert to a digit
        JMP     Short .WRITE_DIGIT  	; Now write this character
..HEX_LETTER:
        ADD     DL,"A"-10           		; Convert to hex letter
..WRITE_DIGIT:
        CALL    WRITE_CHAR          	; Display letter on screen
        POP     DX                  		; Restore old value of DX
        RET

Finally before someone calls out: "Use JAS", and to stay a little bit on
topic. ;-)
I tried to compile this assembler that seems to use these TASM directives,
but, while linking, Make reported a missing library -lfl
Since I have all the required files for DJGPP C and C++ as stated in
readme.1st, I don't know which packet this lib belongs to. Anyone?
A binary version of jas of course would do too. ;-))

Thanks in advance.

-- 
Greetings from sunny Amsterdam,

    Jan Bijsterbosch

email: bijster AT worldonline DOT nl
http://www.worldonline.nl/~bijster