Atari 8 bit Memory Addresses Nicknames

[Grevle]

In the book "Mapping the Atari" certain memory addresses are given certain names, Like address 53278 (DOlE) has the name "HITCLR" -- adress is used to clear the player missile hit register. And address 53248 (D000) named "HPOSPO" - adress is to control horizontal position of player 0.

 

When programming Atari assembler and then assemble with atasm or similar, then it,s nice to have a set of equates for memory addresse in the source code.

 

So those memory addresses Nicknames that are in the book "Mapping the Atari", Are those names generally used in the Atari 8 bit community and also in other books, Like a usual standard to more easily learn the assembly coding or communicate some coding with others and so on..?  

 

 

[+Stephen]

I believe they were used in the OS source code, therefore a standard.  There's tons of source code out there for various assemblers too, which have nice pre-built include files for the OS equates.

[phaeron]

Hardware register and variable names were canonically defined in the Atari OS and Hardware manuals. While Mapping the Atari has its issues, AFAIK it always uses the official names where available.

 

I'd avoid using Atariki for register/variable names, which has a bunch of strange names like GTIACTL instead of PRIOR for $D01B. All official names are six characters at most, anything beyond that was made up by someone.

 

Keep in mind that hardware register addresses don't map 1:1 with names, because frequently there are two different read and write registers at the same address. You cannot read a write-only register or write a read-only register. Even cases like CONSOL or PORTA are not actually purely read/write -- you're reading the input register and writing the output register.

 

[TGB1718]

Have a look at the OS Source Listing, towards the end there's a cross reference listing, I know all variables used are

there too, but you can get the "real" names of any your not sure of.

[Mclaneinc]

I seem to remember a HUGE thick blue fronted OS book that had all the official defined names as well as a full documentation of either the source or the hardware breakdown, possibly there were two huge books, one for each. All I remember is that they weighed a ton and were not cheap (nothing official Atari paperwork ever was).

 

The jist of the matter is that if it's in those books then it's the REAL defined name, other sources may be erroneous.. I forget what the issues were with Mapping the Atari, but I always found it pretty reliable. Not that I coded anything useful for others..

 

And for a bit of trivia, the very books Atari User used, they drove down from Stockport to buy the only one's they could find in the UK from us , hence how I ended up writing for them. Right time, right place and all that..

Edited December 31, 2021 by Mclaneinc

[TGB1718]

I used to have all those books, I remember Atari wouldn't post them and I had to drive to

somewhere in London or Reading (so long ago, can't remember exactly where it was)

and bought them over the "counter".

 

My only regret is I sold nearly all of them off on Ebay some years ago, the only one I still have

is the 1050 Service manual (in pristine condition  )

 

 

[Mclaneinc]

Probably Slough is where you went, I had them all but lost it and all my machines when my mother passed (they were in storage at her place, but they cleared it before asking me)

[TGB1718]

1 hour ago, Mclaneinc said:

Probably Slough is where you went

? spot on that's where I went

[drac030]

10 hours ago, phaeron said:

I'd avoid using Atariki for register/variable names, which has a bunch of strange names like GTIACTL instead of PRIOR for $D01B.

The alternative names Atariki lists beside (not "instead of") those have been in circulation in Europe (or at least in Poland) for more than 30 years now. I think most/all of them come from the reverse-engineered XL OS listings which were published here in printed form around 1989. So you may say that they were made up by someone (as if Atari's official names were not), but still, GTIACTL actually makes much more sense than "PRIOR".