flat assembler
Message board for the users of flat assembler.

Index > Main > 8086 MOVS, CMPS, SCAS, LODS, and STOS

Author
Thread Post new topic Reply to topic
b1528932



Joined: 21 May 2010
Posts: 287
b1528932
am reading intel manual right now, and have a problem. I belived that string instructions were present since beggining, and only ins/outs was added later.

Now i dont know what to thing, everywhere thay write diffrent. Intel manual has in 8086 emulation chapter this statement:

Quote:
The following instructions make up the core instruction set for the 8086 processor. If
backwards compatibility to the Intel 286 and Intel 8086 processors is required, only
these instructions should be used in a new program written to run in real-address
mode.

...

• I/O instructions IN, INS, OUT, and OUTS.
• Repeat prefixes REP, REPE, REPZ, REPNE, and REPNZ.

Why rep/repe exist when none of instructions it could be used with doesnt? WTF!

Quote:
The following instructions, added to later IA-32 processors (some in the Intel 286
processor and the remainder in the Intel386 processor), can be executed in realaddress
mode, if backwards compatibility to the Intel 8086 processor is not required.

...

• String instructions MOVS, CMPS, SCAS, LODS, and STOS.
Post 20 Mar 2011, 14:35
View user's profile Send private message Reply with quote
edfed



Joined: 20 Feb 2006
Posts: 4237
Location: 2018
edfed
don't care about 8086 specificities as more than 99% of working PCs are more than pentium.

time to advance one step, and don't look backward.

if you have a doubt about an instruciton for 8086, try it on your machine, in the eventuallity you have a real 8086.

if not, don't care.
Post 20 Mar 2011, 15:31
View user's profile Send private message Visit poster's website Reply with quote
bitRAKE



Joined: 21 Jul 2003
Posts: 2915
Location: [RSP+8*5]
bitRAKE
INS/OUTS first appeared on 80186.
Post 20 Mar 2011, 15:36
View user's profile Send private message Visit poster's website Reply with quote
b1528932



Joined: 21 May 2010
Posts: 287
b1528932
INS/OUTS first appeared on 80186.

and stos/movs/scas/lods/cmps?
Post 20 Mar 2011, 16:00
View user's profile Send private message Reply with quote
Ninho



Joined: 07 May 2010
Posts: 16
Ninho
b1528932 wrote:
INS/OUTS first appeared on 80186.

and stos/movs/scas/lods/cmps?


These were available always.
Why do'nt you search for a
reference instead of asking
semi-randomly ? I'm /not/
throwing this as a flame, it
just bewilders me why so many
people seem to prefer to post
any silly (or not) question
rather than search for good
reference material and study it
silently. /Then/ if there's
still something you don't
understand it's time to ask the
forums. Just mine and very humble
opinion, of course ;=)
Post 20 Mar 2011, 19:36
View user's profile Send private message Reply with quote
Overflowz



Joined: 03 Sep 2010
Posts: 1046
Overflowz
Offtopic.
Ninho
This forum is not like any others. Here everyone are free to ask questions and share ideas to others. For example for me, this forum is best teacher. people can find things like that but not everyone understands everything and they are asking for more information to know. Next time, try you too Wink
P.S instead of suggesting them what is privately better for them, try to ask on questions and not judge them for their post. Wink
Post 20 Mar 2011, 21:36
View user's profile Send private message Reply with quote
edfed



Joined: 20 Feb 2006
Posts: 4237
Location: 2018
edfed
Ninho wrote:
b1528932 wrote:
INS/OUTS first appeared on 80186.

and stos/movs/scas/lods/cmps?


These were available always.
Why do'nt you search for a
reference instead of asking
semi-randomly ? I'm /not/
throwing this as a flame, it
just bewilders me why so many
people seem to prefer to post
any silly (or not) question
rather than search for good
reference material and study it
silently. /Then/ if there's
still something you don't
understand it's time to ask the
forums. Just mine and very humble
opinion, of course ;=)

http://docs.huihoo.com/help-pc/asm-movs.html
http://docs.huihoo.com/help-pc/asm-outs.html
http://docs.huihoo.com/help-pc/asm-stos.html
http://docs.huihoo.com/help-pc/asm.html
Post 20 Mar 2011, 23:02
View user's profile Send private message Visit poster's website Reply with quote
Ninho



Joined: 07 May 2010
Posts: 16
Ninho
Overflowz wrote:
Offtopic.
...Here everyone are free to ask questions and share ideas to others. For example for me, this forum is best teacher.
people can find things like that but not everyone understands everything and they are asking for more information to know.


I don't disagree, asking the
forum when you couldn't
find authoritative material/ didn't understand/ aren't quite sure you understood understand/ aren't sure you
understood what you found... is
a great way to learn.

What I do find annoying is when
people like the O.P. repeatedly jump onto
their keyboard and type any
random question as a substitute
for making /any/ effort to think
by themselves.

ISTM this kind of behavior is
bad both for the one
questioning, as evidently (s)he
learns nothing; for readers and for the
forum itself, as the contents
become more and more diluted.

Quote:

P.S instead of suggesting them what is privately better for them, try to ask on questions and not judge them for their post. Wink


I'm not judging them, as
it were, morally or legally
they have all rights to ask any
question and hope someone will
bite the bait and answer, again
and again :=)
Post 22 Mar 2011, 18:08
View user's profile Send private message Reply with quote
Overflowz



Joined: 03 Sep 2010
Posts: 1046
Overflowz
Ninho
Maybe they don't have time to search ? and asking it here to make their job more easy ? (Like me.) Hehe it makes me laugh why that makes you nervous ? Razz Enjoy things here mate ))
Regards
Post 22 Mar 2011, 21:37
View user's profile Send private message Reply with quote
Display posts from previous:
Post new topic Reply to topic

Jump to:  


< Last Thread | Next Thread >
Forum Rules:
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


Copyright © 1999-2020, Tomasz Grysztar. Also on YouTube, Twitter.

Website powered by rwasa.