Adding to the x Register

[emkay]

In 2015, it would surprise me to see any number of "power users" who are not using some form of upgrade. Therefore, the bone stock machine becomes the "strange setup."

In 2015 it is surpisingly enough that people code on/for those old machines. The ONLY REAL sense for doing so is to show what the STOCK machines had been capable of.

If you want to use machines with more power, you could buy a new computer anydays.

 

Using those "Hardwareupgrades" makes the coding for that old machines senseless... Amiga is a very good example, even if the machines had been upgraded by C itself.... While the Amiga is "OCS/ECS" , people made stuff working later just on the faster AGA machines with bigger processors. That made the Amiga look worse in colourful graphic games and 3D.

Without the "upgrading" , the quality of "original" Amigas would have been far better.

[xxl]

one day we'll be out of 6502C's and you'll have to convert to a 65C02, which doesn't support undocumented instructions.

 

therefore we should redefine what is Atari XL/XE?

 

You are not changing your beloved Atari into a 16 bit, you are only enhancing its capabilities.

 

no? 65816 - that's 16 bit processor

 

 

 

All I am asking you (and everyone) to do is respect the documented opcodes so everyone can use your software.

 

all I asking you to do is respect with Atari spec., I hope everyone with real Atari would use software written for 16 bit atari xl/xe. - you see how ridiculous are that kind of requests?

 

 

 

the decimal mode problem was a bug which was fixed.

 

so I can't use decimal mode because it works "right" on 65816 but not on Atari cpu?

 

don't you like Atari with 8bit power from the '80? change cpu to 16 bit,

don't you like Atari with ANTIC/GTIA gfx? change it to gfx card,

don't you like Atari with POKEY/GTIA sfx? change it to sound card,

but do not tell me to strip my code for working on this kind of computer. I like my not so powerfull old Atari XL/XE.

[danwinslow]

lol, you guys are wack. Any thread on assembler, no matter how simple, turns into approximately this one with approximately the same people making approximately the same arguments. I'm not really complaining, I ALWAYS learn something, but its just kind of funny.

[Kyle22]

OK, I'm done with this... Some people just don't get it...

 

Did you even read about the 65c816? It is compatible with a 6502, the only difference is it can address more memory, and has more instructions, etc. If you would plug one in your computer, you would not know the difference until you ran a program that uses it. It is THE SAME.

 

Yes, I do like ANTIC/GTIA, but I also like the extra modes provided by the VBXE. It does not take anything away from the Atari experience, only enhances it.

 

I also like PoKey. Do you have a problem with 2 of them for stereo? Oooooh wait, that's not how Atari originally designed it.... Scary thought...

 

I like ALL Ataris, so unless you're writing a new program that requires the 816, or some other upgrade, please be considerate, and write proper software that everyone can use.

 

Could this be a jealousy thing? People with that mindset feel inferior because they don't have an 816, so they take an attitude with those that do.

[snicklin]

Whether or not today's developers respect the new processor, there are developers from the past who didn't (as there was only 1 processor). Therefore when you are purchasing a 16 bit processor, you are accepting that some software will not work with it. Therefore you should either purchase another Atari or not upgrade if you want 100% compatibility. Compatibility is the choice of the modern developer. It is correct that people here point out incompatibility but can not demand it. If they can achieve something great with illegal op-codes which couldn't without them, they should use them.

[snicklin]

People write games in English knowing full well that a Mandarin only speaker cannot play them.

 

People write demos in PAL only.

 

If a demo can be written for PAL and PAL only, it is better that this is created in the first place then saying "No, because I can't achieve those effects in NTSC, I shouldn't create it".

 

Lets be respectful however that we try to keep compatibility wherever possible, but if it isn't possible for whatever you want to achieve, then so be it.

[+Stephen]

lol, you guys are wack. Any thread on assembler, no matter how simple, turns into approximately this one with approximately the same people making approximately the same arguments. I'm not really complaining, I ALWAYS learn something, but its just kind of funny.

Yup - as many people as I have complementing me for my over the top 300 HP motor in my 87 Daytona, there are the same # of people screaming at me for not keeping it 100% stock. Hey man - I rescued this thing from the crusher, I will build it as I see fit.

[Grevle]

I think its nice in 2015 that people code for the Atari 8-Bit. Im a amateur assembler programmer so my progams hardly shows what the Atari is capable of, But im nostalgic when it

comes to the Atari 8-bit and enjoy create anything for it even though its simple, just being in touch with The 80's era Hardware is kinda special and interesting and rewarding.

[Kyle22]

Yup - as many people as I have complementing me for my over the top 300 HP motor in my 87 Daytona, there are the same # of people screaming at me for not keeping it 100% stock. Hey man - I rescued this thing from the crusher, I will build it as I see fit.

87 Daytona, 300 HP... One word... AWESOME

 

I had an 89 GTC Turbo III intercooled with 5 speed. I love those things!

 

Edit: Sorry, off-topic.

Edited May 12, 2015 by Kyle22

[tschak909]

To all those people who saw fit to derail this topic, and start this other senseless topic:

 

[pirx]

lol, you guys are wack. Any thread on assembler, no matter how simple, turns into approximately this one with approximately the same people making approximately the same arguments. I'm not really complaining, I ALWAYS learn something, but its just kind of funny.

 

Yea, some men have their extra extra large agenda and one learns to ignore these zealous ramblings

[drac030]

Lets be respectful however that we try to keep compatibility wherever possible

 

That is the entire point. Some people look like they are enforcing illegal opcodes just to make life harder for those who have 65C02/C816 in their Ataris. "Because this CPU was not there in the past". But *now* it is not the past, so that is not an argument: *today* some Ataris have such a mod (just as many other mods there are there) and that is a fact. I see no point in making it a quasi-religious dogma that we should only use the stuff that was available only before 1990 (or something like that). This stuff does exist today "on the market".

 

Besides, the entire 65xx line of processors is backwards compatible, so it takes completely no effort in making programs which run equally well on 6502, on 65C02 or on 65C816: it is enough to stick to the legal 6502 instruction list (the few problems that remain can be probably less or more easily patched out by those who are interested).

 

As for "developers in the past", unaware about the new CPU: surprisingly, most (like 95%) old software is compatible and runs very well on 65C816. The fixation on 6502 illegal instructions and/or deliberate ousting of 65C816 is rather today's thing. It goes as far as some demo, which could run on 65C816 unless the author did not deliberately block execution on that processor, giving as a reason, that "timings are different and this affects the program". The humorous point here is that that same program is (also deliberately) allowed to run on 65C02, and 65C02 instructions timings are more off from 6502 timings than 65C816 from 6502. For me this clearly demonstrates that the term "fixation" I just have used, is justified.

 

And, last but not least, stuffing a program with illegal opcodes guarantees it to be less popular, because f.e. I personally will rather delete the non-working program than replace the better CPU with the older model.

Edited May 12, 2015 by drac030

[Heaven/TQA]

drac030... in my position it's simply my creative decision to do what I want same like yours to delete what you want

[xxl]

Atari users do not have to worry about that, users with transform computers must face some incompatibilities with Atari software... and delete it

[emkay]

Atari users do not have to worry about that, users with transform computers must face some incompatibilities with Atari software... and delete it

Deleting optimized code for original Ataris. What could that mean?

[xxl]

if soft that runs fine on oryginal Atari do not work on your computer then:

1. time to buy Atari

2. time to use emulator

3. time to delete software and pretend that you still have Atari and nothing had happened

Edited May 12, 2015 by xxl

[flashjazzcat]

It seems simple enough to me: if the situation absolutely demands illegal opcodes, use them and accept the consequences. For 99 percent of other coding jobs they're arguably unnecessary (and many illegal opcodes seem to me like unintended behaviours looking for a purpose), and it would be best not to advocate their use for non-critical tasks by those beginning in assembly language.

[drac030]

I can only add to my post that arguing for "original" (= unmodded) Atari, and insisting that a modded one is not an Atari anymore, while personally using not an Atari at all, but a PC for everything (write programs in a PC editor; compile on a PC using a cross-assembler; run/test using an emulator on a PC) is a clear-cut case of hypocrisy.

 

And (different case) insisting that the only original, justified Atari setup is 130XE + unmodded 1050, while personally not using a 1050 as a storage, but rather a SIO2SD, is (IMHO) a case of the exact same mental disorder.

[tschak909]

Guys...you derailed...a beginner topic... all of you.... _ALL OF YOU_ ... you know who you are, need to be thwacked with a brick.

 

-Thom

[ZylonBane]

Guys...you derailed...a beginner topic... all of you.... _ALL OF YOU_ ... you know who you are, need to be thwacked with a brick.

A beginner topic in which the question was answered by the second post.

[JamesD]

I would appreciate it if your software doesn't break on a 65816 but it's the programmer's prerogative, just as it's a programmer's prerogative to support the 65C02 or 65816 and not the 6502.

FWIW, there were programmers that insisted on banging the hardware direct and ignoring the rules on the Amiga.
I patched several Amiga demos to use the OS waitblit so they ran fine on 68030 machines and they still ran fine on 68000 machine in spite of claims to the contrary.
But not all programs ran successfully on the 68000 after the same kind of patching.

As long as you don't use "illegal instructions" unless you absolutely have to there shouldn't be any problem.
Frankly, I've written code for the Apple II that can be assembled for the 6502 or 65C02, it's not that difficult.

As for the topic being derailed, it's an important discussion. A beginner should be aware of the consequences of using the undocumented opcodes.
I think it's important the OP hear both sides of the argument even if some people approached the conversation like 12 year olds.

Edited May 12, 2015 by JamesD

[Grevle]

That was a long answer to a short question. Being a beginner with assembler i like to write code for the stock 64k XE Atari, So for my use the ADC and SBC to add or subtract values in equates will suffice and also its easier to learn and make more sence to a beginner in assembler. So i be using the accumulator instead of X register to add or substract.

Edited May 12, 2015 by BioFreeze

[Joey Z]

 

 

therefore we should redefine what is Atari XL/XE?

not at all, they were called undocumented op codes for a reason. Officially, they weren't ever a part of anything in the first place, so you're not redefining anything.

 

anyway, point is, if you write things with undocumented op codes, and I get a 65816, I'll nicely ask you to fix it, and when you get pissy like this again, then I'll choose to not use it. Or maybe I'll fix it myself. depends on if it's software I actually want to use.

[Heaven/TQA]

It seems simple enough to me: if the situation absolutely demands illegal opcodes, use them and accept the consequences. For 99 percent of other coding jobs they're arguably unnecessary (and many illegal opcodes seem to me like unintended behaviours looking for a purpose), and it would be best not to advocate their use for non-critical tasks by those beginning in assembly language.

True.... But the dark side is quicker, easier, more seductive...

 

And I tend to say that SAX, LAX would help you in your bitmap rendering and masking code

Edited May 12, 2015 by Heaven/TQA

[emkay]

not at all, they were called undocumented op codes for a reason. Officially, they weren't ever a part of anything in the first place, so you're not redefining anything.

Funny. All the crap that happened with the Atari, many bugs made not all features usable. But , at least, the core of the machine was the same from 1979 to the 90s ... a part of that is the "undocumented" opcodes, also the "GTIA" Bug and the POKEY timing. It's all the same in that huge timespan. So those "features" have become "common" in that machines, SO THEY SHOULD be used. And, if someone asks for "adding the X register" it is 100% correct to point to those opcodes, because the're in the Rule of the A8, instead of still taking nonsense out of the book....

"Undocumented" means only that someone forgot to put those to the documentation and could cause problems with "Upgrades". But the Upgrade... the real 16 Bit Atari never had been released. And, you know what? History writes the best books.

Heck... Atari sold almost the same machines from 1979 as "new" for such a long time... even the C64 had several Hardwareupdates...

It's the common parts that define the machine...

Edited May 12, 2015 by emkay