16 Aug
2014
16 Aug
'14
9:45 a.m.
Was there more or less a standard or reference 6502 assembly language (e.g.
from MOS) with regard to syntax and pseudo ops? With
the cpu being used in
so many different computers, and so many vendors writing their
own
assemblers for each platform, did the assemblers tend to resemble each
other (besides the instruction set), or did everyone tend to do their own
thing?
16 Aug
16 Aug
10:44 a.m.
Hi A.P,
The data sheets are out there; I've seen about three different datasheets
for the 6502 floating around, one is the original MOS preliminary, there's
a Synertek one, and there's the brand new one from WDC. I'm sure you could
find more if you hunted around.
It's all the same op-codes and addressing modes; except in the currently
shipping 65C02(S) they added a few instructions and filled out a few pins
that aren't present in the earlier revs. So if you are working with an
older 6502, use the older datasheet; if you just went out and got a brand
new one from WDC, use the new data sheet.
Other than that, any old 6502 data sheet is about as definitive as it gets
:)
If you are talking about assembler macros and stuff like that, I'm sure
there are as many variants as there were assemblers, little to no
standardization there from my experience, LOL. But regardless of the
computer, it's the same 6502 and same op-codes underneath.
I'm in the middle of doing a little 6502 SBC right now so I've been poring
through these publications quite a bit over the course of the last few
weeks ;)
Another neat reference is 'The 6800 Processor' by Jack Quinn, I know it's
not 6502-specific but the two CPUs were so similar, there's a lot of
relevance... nice book discussing the programming model on these CPUs
including a very thorough treatment on hand-assembly which I found to be
quite educational.
Best,
Sean
On Sat, Aug 16, 2014 at 9:45 AM, A. P. Garcia <a.phillip.garcia at gmail.com>
wrote:
Was there more or less a standard or reference 6502
assembly language (e.g.
from MOS) with regard to syntax and pseudo ops? With the cpu being used in
so many different computers, and so many vendors writing their own
assemblers for each platform, did the assemblers tend to resemble each
other (besides the instruction set), or did everyone tend to do their own
thing?
11:01 a.m.
It is electrically different to the 6800 not to confuse the two chips,
different clock etc
There was a Rockwell version too
Dave Caroline
On 16/08/2014, Sean Caron <scaron at umich.edu> wrote:
Hi A.P,
The data sheets are out there; I've seen about three different datasheets
for the 6502 floating around, one is the original MOS preliminary, there's
a Synertek one, and there's the brand new one from WDC. I'm sure you could
find more if you hunted around.
It's all the same op-codes and addressing modes; except in the currently
shipping 65C02(S) they added a few instructions and filled out a few pins
that aren't present in the earlier revs. So if you are working with an
older 6502, use the older datasheet; if you just went out and got a brand
new one from WDC, use the new data sheet.
Other than that, any old 6502 data sheet is about as definitive as it gets
:)
If you are talking about assembler macros and stuff like that, I'm sure
there are as many variants as there were assemblers, little to no
standardization there from my experience, LOL. But regardless of the
computer, it's the same 6502 and same op-codes underneath.
I'm in the middle of doing a little 6502 SBC right now so I've been poring
through these publications quite a bit over the course of the last few
weeks ;)
Another neat reference is 'The 6800 Processor' by Jack Quinn, I know it's
not 6502-specific but the two CPUs were so similar, there's a lot of
relevance... nice book discussing the programming model on these CPUs
including a very thorough treatment on hand-assembly which I found to be
quite educational.
Best,
Sean
On Sat, Aug 16, 2014 at 9:45 AM, A. P. Garcia <a.phillip.garcia at gmail.com>
wrote:
Was there more or less a standard or reference
6502 assembly language
(e.g.
from MOS) with regard to syntax and pseudo ops? With the cpu being used
in
so many different computers, and so many vendors writing their own
assemblers for each platform, did the assemblers tend to resemble each
other (besides the instruction set), or did everyone tend to do their own
thing?
11:20 a.m.
Oh, yes, sorry, I hope I wasn't unclear in my previous message; the only
similarity between 6800 and 6502 is the general machine architecture and
programming modality (they also share many assembly mnemonics). The 6800
and 6502 are not op-code or pin compatible.
I just referenced the Quinn text because I think it's pretty good for the
high-level concepts and I'm not aware of any similar publication dedicated
to the 6502 specifically.
Best,
Sean
On Sat, Aug 16, 2014 at 11:01 AM, Dave Caroline <dave.thearchivist at gmail.com
wrote:
> It is electrically different to the 6800 not to confuse the two chips,
> different clock etc
> There was a Rockwell version too
>
> Dave Caroline
>
> On 16/08/2014, Sean Caron <scaron at umich.edu
wrote:
> > Hi A.P,
> >
> > The data sheets are out there; I've seen about three different datasheets
> > for the 6502 floating around, one is the original MOS preliminary,
> there's
> > a Synertek one, and there's the brand new one from WDC. I'm sure you
> could
> > find more if you hunted around.
> >
> > It's all the same op-codes and addressing modes; except in the currently
> > shipping 65C02(S) they added a few instructions and filled out a few pins
> > that aren't present in the earlier revs. So if you are working with an
> > older 6502, use the older datasheet; if you just went out and got a brand
> > new one from WDC, use the new data sheet.
> >
> > Other than that, any old 6502 data sheet is about as definitive as it
> gets
> > :)
> >
> > If you are talking about assembler macros and stuff like that, I'm sure
> > there are as many variants as there were assemblers, little to no
> > standardization there from my experience, LOL. But regardless of the
> > computer, it's the same 6502 and same op-codes underneath.
> >
> > I'm in the middle of doing a little 6502 SBC right now so I've been
> poring
> > through these publications quite a bit over the course of the last few
> > weeks ;)
> >
> > Another neat reference is 'The 6800 Processor' by Jack Quinn, I know
it's
> > not 6502-specific but the two CPUs were so similar, there's a lot of
> > relevance... nice book discussing the programming model on these CPUs
> > including a very thorough treatment on hand-assembly which I found to be
> > quite educational.
> >
> > Best,
> >
> > Sean
> >
> >
> >
> > On Sat, Aug 16, 2014 at 9:45 AM, A. P. Garcia <
> a.phillip.garcia at gmail.com>
> wrote:
> >
> >> Was there more or less a standard or reference 6502 assembly language
> >> (e.g.
> >> from MOS) with regard to syntax and pseudo ops? With the cpu being used
> >> in
> >> so many different computers, and so many vendors writing their own
> >> assemblers for each platform, did the assemblers tend to resemble each
> >> other (besides the instruction set), or did everyone tend to do their
> own
> >> thing?
> >>
> >
>
11:31 a.m.
On Sat, Aug 16, 2014 at 9:44 AM, Sean Caron <scaron at umich.edu> wrote:
<snip>
If you are talking about assembler macros and stuff
like that, I'm sure
there are as many variants as there were assemblers, little to no
standardization there from my experience, LOL. But regardless of the
computer, it's the same 6502 and same op-codes underneath.
Yes, that's what I was getting at. Given the lack of standardization,
my next set of questions would be: Was there a specific 6502 assembler
that you particularly enjoyed working with? Was there a dominant one
on the market--i.e. is there a particular assembler for which a
majority of available code was written for? Probably the most famous
bit of 6502 asm out there is the Apple II Prince of Persia
[https://github.com/jmechner/Prince-of-Persia-Apple-II]. Which
assembler(s) can process this source as-is?
I'm in the middle of doing a little 6502 SBC right
now so I've been poring
through these publications quite a bit over the course of the last few
weeks ;)
Another neat reference is 'The 6800 Processor' by Jack Quinn, I know it's
not 6502-specific but the two CPUs were so similar, there's a lot of
relevance... nice book discussing the programming model on these CPUs
including a very thorough treatment on hand-assembly which I found to be
quite educational.
Nice. Thanks for the recommendation.
12:10 p.m.
On Sat, 16 Aug 2014, A. P. Garcia wrote:
Date: Sat, 16 Aug 2014 08:31:18
From: A. P. Garcia <a.phillip.garcia at gmail.com>
Reply-To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at
classiccmp.org>
Subject: Re: standard 6502 syntax?
On Sat, Aug 16, 2014 at 9:44 AM, Sean Caron <scaron at umich.edu> wrote:
<snip>
Thank you for the github link.
I think that the assembler source for Prince of Persia was
written for the Merlin version 2.52 assemlber. See the line:
* Merlin 2.52 --> RW18 "USR" interface routine.
near the top of the file "04 Support/MakeDisk/USR18.S".
--Ernest
If you are talking about assembler macros and
stuff like that, I'm sure
there are as many variants as there were assemblers, little to no
standardization there from my experience, LOL. But regardless of the
computer, it's the same 6502 and same op-codes underneath.
Yes, that's what I was getting at. Given the lack of standardization,
my next set of questions would be: Was there a specific 6502 assembler
that you particularly enjoyed working with? Was there a dominant one
on the market--i.e. is there a particular assembler for which a
majority of available code was written for? Probably the most famous
bit of 6502 asm out there is the Apple II Prince of Persia
[https://github.com/jmechner/Prince-of-Persia-Apple-II]. Which
assembler(s) can process this source as-is?
I'm in the middle of doing a little 6502 SBC
right now so I've been poring
through these publications quite a bit over the course of the last few
weeks ;)
Another neat reference is 'The 6800 Processor' by Jack Quinn, I know it's
not 6502-specific but the two CPUs were so similar, there's a lot of
relevance... nice book discussing the programming model on these CPUs
including a very thorough treatment on hand-assembly which I found to be
quite educational.
Nice. Thanks for the recommendation.
2:09 p.m.
Is there an assembler for which a
majority of available code was written for? Probably the most famous
bit of 6502 asm out there is the Apple II Prince of Persia
The mnemonics for the 6502 instruction set were pretty well known. As far as macros and
such, back in the early 80s I wrote a 6502 assembler in C that ran on our 11/34 (unix),
and used the M4 preprocessor. This was in support of software development on Commodore 64
and superpet systems.
3:03 p.m.
On Aug 16, 2014 1:12 PM, "Roe Peterson" <roeapeterson at gmail.com>
wrote:
Of course. I'm wondering about other conventions, e.g. how to delineate
comments, the types of pseudo ops that were necessary, macros, that sort of
thing. I've only really done x86 assembly to any meaningful extent, where
for example there's "intel syntax" which is the order of operands that you
see in the data sheets, and "at&t syntax", which reverses that order. At
first some of these things were a bit different among assemblers, but
eventually most of them tried to be masm compatible...
good show. I happen to be a c, unix, and dec pdp&vax junky, so I find your
choice to platform to be in the finest of taste. :-)
Is there an assembler for which a
majority of available code was written for? Probably the most famous
bit of 6502 asm out there is the Apple II Prince of Persia
The mnemonics for the 6502 instruction set were pretty well known. As far as macros and such, back in the early 80s I
wrote a 6502 assembler
in C that ran on our 11/34 (unix), and used the M4
preprocessor. This was
in support of software development on Commodore 64 and superpet systems.
5:10 p.m.
On Sat, 16 Aug 2014, A. P. Garcia wrote:
Is there an assembler for which a
majority of available code was written for? Probably the most famous
bit of 6502 asm out there is the Apple II Prince of Persia
Do you want to assemble Prince of Persia? If you're using
an Apple II (or an emulator) you could use the assembler
Merlin -- see my earlier message about PoP using Merlin.
Various different versions of Merlin can be downloaded from
http://apple2online.com/index.php?p=1_27_Software-M-P
There were many 6502 assemblers that ran on the Apple II, but
Merlin and Lisa were the most popular.
Of course. I'm wondering about other conventions, e.g. how to delineate
comments, the types of pseudo ops that were necessary, macros, that sort of
thing. I've only really done x86 assembly to any meaningful extent, where
for example there's "intel syntax" which is the order of operands that you
see in the data sheets, and "at&t syntax", which reverses that order. At
first some of these things were a bit different among assemblers, but
eventually most of them tried to be masm compatible...
Do you want to learn 6502 assembler in general? If so, you
can focus on the standard op codes, but the various assemblers
use a wide variety of mutually-incompatible syntaxes for macros
and pseudo-ops. You'd probably be best off to get the manual
for Merlin or some other popular 6502 assembler. The manual
for Merlin 8/16 can be downloaded from
http://www.apple-iigs.info/doc/fichiers/merlin816.pdf
Randy Hyde's book "How to Program the 6502 Using Assembly
Language" can be downloaded from
(two lines, glue them together)
ftp://ftp.apple.asimov.net/pub/apple_II/documentation/
programming/6502assembly/Using%206502%20Assembly%20Language.pdf
Best wishes,
--Ernest
5:43 p.m.
On Aug 16, 2014 4:15 PM, "Ernest G. Allen" <eallen at owt.com> wrote:
Thanks for all your help! I really appreciate it.
On Sat, 16 Aug 2014, A. P. Garcia wrote:
sort of
Is there an assembler for which a
majority of available code was written for? Probably the most famous
bit of 6502 asm out there is the Apple II Prince of Persia
Do you want to assemble Prince of Persia? If you're using
an Apple II (or an emulator) you could use the assembler
Merlin -- see my earlier message about PoP using Merlin.
Various different versions of Merlin can be downloaded from
http://apple2online.com/index.php?p=1_27_Software-M-P
There were many 6502 assemblers that ran on the Apple II, but
Merlin and Lisa were the most popular.
>
> Of course. I'm wondering about other conventions, e.g. how to delineate
> comments, the types of pseudo ops that were necessary, macros, that > thing. I've only really done x86 assembly to
any meaningful extent,
where
> for example there's "intel syntax"
which is the order of operands that
you
see in the
data sheets, and "at&t syntax", which reverses that order. At
first some of these things were a bit different among assemblers, but
eventually most of them tried to be masm compatible...
Do you want to learn 6502 assembler in general? If so, you
can focus on the standard op codes, but the various assemblers
use a wide variety of mutually-incompatible syntaxes for macros
and pseudo-ops. You'd probably be best off to get the manual
for Merlin or some other popular 6502 assembler. The manual
for Merlin 8/16 can be downloaded from
http://www.apple-iigs.info/doc/fichiers/merlin816.pdf
Randy Hyde's book "How to Program the 6502 Using Assembly
Language" can be downloaded from
(two lines, glue them together)
ftp://ftp.apple.asimov.net/pub/apple_II/documentation/
programming/6502assembly/Using%206502%20Assembly%20Language.pdf
Best wishes,
--Ernest 
17 Aug
17 Aug
5:28 p.m.
On Sat, Aug 16, 2014 at 11:09 AM, Roe Peterson <roeapeterson at gmail.com> wrote:
Heh. At the same time, I was writing a 6502 emulator in FORTRAN on a
VAX, and set set of macros for the VAX assembler that allowed me to
use it as a 6502 assembler. In support of Atari 400/800 software
development.
-- Charles
Is there an assembler for which a
majority of available code was written for? Probably the most famous
bit of 6502 asm out there is the Apple II Prince of Persia
The mnemonics for the 6502 instruction set were pretty well known. As far as macros and
such, back in the early 80s I wrote a 6502 assembler in C that ran on our 11/34 (unix),
and used the M4 preprocessor. This was in support of software development on Commodore 64
and superpet systems.
16 Aug
16 Aug
6:10 p.m.
It was thus said that the Great A. P. Garcia once stated:
Probably the most famous bit of 6502 asm out there is the Apple II Prince
of Persia [https://github.com/jmechner/Prince-of-Persia-Apple-II]. Which
assembler(s) can process this source as-is?
Wouldn't the bit shown in the movie "Terminator" be a bit more famous?
-spc
3661
days inactive
3662
days old
11 comments
7 participants
participants (7)
-
a.phillip.garcia＠gmail.com -
charles.unix.pro＠gmail.com -
dave.thearchivist＠gmail.com -
eallen＠owt.com -
roeapeterson＠gmail.com -
scaron＠umich.edu -
spc＠conman.org