From: Mike purtell <mtp4 AT pge DOT com>
Newsgroups: comp.os.msdos.djgpp
Subject: error: operator size not specified
Date: Wed, 17 Feb 1999 09:02:45 -0800
Organization: Pacific Gas And Electric Company
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Message-ID: <36CAF635.4E2454D6@pge.com>
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To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp
Reply-To: djgpp AT delorie DOT com

This could probably be cleared up a lot easier if I had Mathew
Mastracci's email ID ( This is from his "how to nasm with DJGPP"
tutorial section 4.3 [and this sucker won't compile]) but since I
don't...

The following function bails at the line

 mov [VideoRAM], 0ffffh

with the error message  "operator size not specified" emenating from the
nasm compiler.
Since this is (n)asm but calls dj lib-function
__dpmi_segment_to_descriptor I didn't know whether to post here or a
comp.lang.asm.x86 or elsewhere...

Here's the function
;
---------------------------------------------------------------------------

; Prototype: int InitGraphics(void);
; Returns: -1 on error, else zero
;
---------------------------------------------------------------------------

_InitGraphics__Fv:
 push ebp
 mov ebp, esp

 push dword 0a000h                     ; Push segment for function
 call ___dpmi_segment_to_descriptor    ; Note the triple underscore
 cmp eax, -1                           ; Check for error
 jne .SelectorOkay                     ; No error, selector is valid

 mov [VideoRAM], 0ffffh                ; Error, make selector invalid /*
CHOKE !! */
 jmp .Done                             ; End function, will return -1

.SelectorOkay:
 mov [VideoRAM], ax                    ; Load selector from ax
 xor eax, eax                          ; Clear eax to return zero

.Done:
 mov esp, ebp
 pop ebp
 ret
;--------------------------------------------
You got it, I'm REAL new to this asm stuff...
I did define the VideoRAM symbol as
VideoRAM    dw 0000hand declared the function
[GLOBAL _InitGraphics__Fv]
in the header

If it would help to post the whole asm module and .cc please say so.

is there any dj help ot there ?
Mike Purtell
mtp4 AT pge DOT com