beginner Assembler question

[Reck]

could someone tell me just what 'space=data', 'align=1' and 'segment my_data' does?
Yes, it's for schoolwork - unfortunately they didn't bother handing us a book nor explaining it; unless you wanna call 30 lines in notepad an explanation. (and yes, I tried Google, oh Lord how did I try )

DEFINE my_data,space=data ,align=1,ORG=data_ram

and segment my_data
<lots of variables come here>

[Darkwraith]

I know what the segment my_data probably means. That is probably your data segment. This is where you put all of your data (variables and constants) in. I find that different assemblers treat this differently (like MASM and NASM.)

I am not sure of the others, atm.

[chemicalNova]

I would assume the DEFINE part is just like the C equivalent. I also assume this is MASM, since DEFINE isn't a valid statement in Turbo Assembler..


Phreak

[Darkwraith]

The problem is that there are several different assemblers and each has their own take of the syntax.

This is evident in the differences between MASM and NASM.

[chemicalNova]

MASM is just different. I like MASM, but its turning into C. They have so many different macros now, that you could almost run a full C file in MASM, and compile it.

Phreak

[Darkwraith]

( My aside: )
That is the reason why I cannot see large scale projects written in assembler. Most of the end result looks like C and the rest becomes a jumble of loops. Asssembler, however, is excellent for small bits of code that need to be optimized.
( End aside )

Have you taken a look at HLA? The arguments that you send to the instructions are backwards from the regular 80x86 syntax.

I founda site that illustrates this:
http://board.win32asmcommunity.net/p...ddressingModes

[chemicalNova]

Ah. I've never actually seen this, thanks for the link.

I don't think you'll find many people willing to begin a massive project in any type of ASM.

Phreak

[LeeC]

Originally posted by Reck
could someone tell me just what 'space=data', 'align=1' and 'segment my_data' does?
Yes, it's for schoolwork - unfortunately they didn't bother handing us a book nor explaining it; unless you wanna call 30 lines in notepad an explanation. (and yes, I tried Google, oh Lord how did I try )

DEFINE my_data,space=data ,align=1,ORG=data_ram

and segment my_data
<lots of variables come here>

I suspect that the line is saying that you are defining a segment of memory (segments used to be and I assume still are 64k blocks of memory on 64k boundaries 0 - 65535, 65536 - etc...) It's a while since I did any PC assembler language.

The segment type is data

The align=1 I suspect means it is Byte aligned rather than word aligned.

and the ORG tells it that the the space is placed at a memory location referred to by data_ram, usually org would be followed by a memory address eg. ORG $8000 but by using a label, you can change the address of the label to move your data in memory if the preceeding segment gets full.

Hope I have remembered this stuff correctly and that it helps, although I notice this post is fairly old now... only just joined this forum though... soz.

[Darkwraith]

What assembler do you suspect that this code was generated for?

[LeeC]

I'm not too sure to be honest, the last time I was doing any assembler on the PC it was in DOS using A86/D86 which was a shareware assembler and it looks similar to what was used then but not identical.

I could of course be completely wrong with my answer as I am speculating on the terminology. I haven't used any of the Windows based assembler packages and it is several years since I did any PC assembler... actually, come to think of it, it's a lot of years... god I'm too old..

[chemicalNova]

Hehe. I'm say you are right. I've never seen this in any assembler I've used.

Tis a stumper

Phreak