122 replies to this topic

[TMR]

SIO99, on Mon Apr 23, 2012 8:21 PM, said:

Are you a double agent from Commodore?

Double agent? No, that'd imply that i make some kind of secret of liking or having twenty five years coding experience with the C64. i've also got seven years programming the Atari 8-bit in machine code and a fairly extensive list of other platforms under my belt, but people here seem to forget that as soon as the C64 is mentioned...

SIO99, on Mon Apr 23, 2012 8:21 PM, said:

This is the first time I've heard of any claim of accessing anything like 63K RAM on a Commodore 64. I could try and sum up what a certain magazine said.

[Snip for brevity]

Short version; never trust a magazine to give you correct technical information without consulting a programmer too. =-)

The only truly tricky space to use is under the I/O - disabling it turns off the VIC-II, SID and I/O registers as well as the colour RAM (which exists outside of the standard 64K, technically a C64 has a little shy of 65K), but you can still write to the screen RAM in that state and the most common use for that area i've seen is graphics data - which has to be somewhere, so might as well be in the space it's a little harder to keep code in.

SIO99, on Mon Apr 23, 2012 8:21 PM, said:

The Sinclair Spectrum 48K had more RAM free to BASIC than the Commodore 64!

No, it has more free RAM for BASIC programs but not to BASIC as a whole. Have a look at the C64's memory map at $c000 to $cfff, that space is available for BASIC to use for storage, data, graphics whatever. 4K on top of the 38K for BASIC programs is 42K.

Oh, and getting back onto the topic at hand; what Heaven said about WSYNC.

[TMR]

SIO99, on Mon Apr 23, 2012 10:15 PM, said:

I never studied 6502 Assembly Language until recently, only Z80 and 68000. I now see that it's more simple than Z80 Assembly Language, but I studied a Z80 Assembler course which criticised the 6502 for having so few registers.

Most Z80 programmers look at the 6502 like that, but the actual situation is a little more complicated; with the Z80, a register pair has to be used as pointers to a location in RAM so it's possible to run out of registers quite quickly if accessing multiple locations in one pass. With the 6502, the registers don't point at addresses in that way and instead two bytes of the zeropage (the first page of memory, which can be addressed faster than the rest of it) take care of the address and the registers are used for moving data between points and offsets from those addresses.


Oh, on topic again: i've always loved Moon Patrol.

[potatohead]

The programming comments are interesting.  I personally preferred programming on the Apple ][.  That was my first real experience outside of a few BASIC programs written on the neighbors TRS-80 Model I, which got me hooked big, crappy as that computer was.

Apples were cool, because they had a real system monitor, a faster integer BASIC, if one wanted that, and mini-assembler, with some goodies, like the shape tables capability.  Turn it on, and you are kind of set, ideally with a DOS, but maybe not, just turn it on and a fairly sophisticated program could be written with what one found "in the box"  My first assembly language programs were authored on an Apple, as were a fair number of ASM bits for the Atari.  I would mini-assemble them, noting the bytes that needed changing to relocate and repoint things and take it home for DATA statements...

Of course, that drove getting MAC/65, which was a superior environment overall, but for lack of 80 column display.  That's probably the biggest short coming of many home computers, IMHO.  Real easy to get used to the higher character density, and once that happens...

I used to use some software 80 column thing on the Atari a lot.  Worked fairly well for BASIC programs too.  I know there were similar things for other computer, generating 64 columns, or 80, depending on what the graphics system would do.  Ate up 8K or so of RAM tho'  

Barring some of those things, I liked the Atari BASIC because it did include commands for some of the better machine features, and it was fairly quick compared to some.  APPLESOFT was slower, though the integer BASIC was significantly faster.  You know, the VIC 20 was damn fast in BASIC.  That BASIC didn't do much, but a little assembly added, and I thought it was pretty sweet.  You all benchmarked the various machines right?  We did.

When I was about 16, some of us formed a club with some guy who really knew his stuff running it.  He was a CoCo fan, and of course promptly polluted us with the greatness of that chip.  Never did a lot of Z80 assembly, because I didn't have a machine.  I did 6809 though.  Sweet.

I think somebody wanting to learn to program could do way worse than an Atari, but they could do better too, and a whole lot depends on what the person wanted to do.  IMHO, the Apple was better equipped to write serious programs, because it could display data and it featured a lot of options, like taking input from serial, used with ADT today, and the monitor that made them possible.  Lots in the box, but then again that box cost $$$ too.  Ataris were a great bang for the buck, in that regard.  Adding some tools really made the difference.  I regret not trying "Action!" moving from BASIC to ASM, to C fairly quickly, as I moved onto DOS and UNIX, where the environments could really support C.  First C program on the Apple was hilarious.  If one had 4 disks, sweet!  If not, pop two in, edit program, swap one, run compiler, link, swap one, output object code, swap one, boot, run, ugh...

Anyway, it's fair I guess.  Memory free under BASIC mattered, if one was just doing BASIC, as did the special commands.  The three machines I computed on a lot, all had BASIC support for graphics and sound, sans the Apple, which did require some assembly required to get any sound besides that classic "beep"  POKEY was notable, because one could ask for basic sounds, which would then just continue to happen, where the CoCo and Apple took some work, and really didn't do polyphonic sound without tricks, unknown to me then.

Writing a little music sequencer on Atari was kind of cake.  Load up the notes in DATA statements, write a loop, and dump them to the POKEY, easy cheezy!  

Another awesomeness was the goodies one found in the magazines!  What a great time!  Miss that the most.  Go with Mom to snag some food, and score BYTE, COMPUTE, ANTIC, etc...  Run home, fire up the machine, and GO!  Good stuff would happen or a type in game.  COMPUTE actually published some pretty great ones, featuring assembly language.

So, the VIC 20 would do wide screen?  Cool.  Didn't know.

Today then, none of that really matters does it?  We can go and get a great machine, no need to worry about $$$ or RAM, just stuff it, and go!  We've got emulators too, meaning we can code on a modern box, then see it all happen on the real deal.  Programming on the real deal seems so limiting now, particularly in 40 columns.  The only machine I really feel like authoring on is the Apple, though I do input BASIC programs on the Atari to see something, hear a sound, plot some dots, test an idea, or to just remember...

[potatohead]

Re:  Video signal.

Yes.  Honestly, the Apple has a first class looking signal too.  I had a C64 for a while, and I thought it looked pretty great on composite.  Never did use it with RF.  It does have color fringing though, due to it's full use of the NTSC signal.

Atari's are distinct in that way, because they don't do that, and have a broad palette.  Other machines, like Apple and CoCo, and I think VIC 20, all didn't use phase change to generate color, so they had rock solid displays, but limited color choices.  The VCS and Atari 8 bit computers look distinctive because the color set is distinctive.  Always liked that, but it does limit the color resolution of the machine to 160 pixels normal DMA.  Notably, many Atari games were abstract things, distinctive.  Always thought the video system influenced that, and it's kind of awesome.  The lack of color, square pixels impacts things, just as having square pixels impacts things.  Not a better statement here, just reflecting on stuff from that time.  Fun stuff, mind you.

Edit:  This just triggered a great memory.  For a short time, I had a TI.  Got rid of it, and shouldn't have, because I had the full deal, metal expansion box, disk, etc...  God!  That was a TANK.  Anyway, I kept one part of it, the RF modulator.  Damn, TI did it spot on right, where the RF box hung right on the back of the TV.  Those things, even today, if you can find one, generate an awesome signal, on par with straight composite.  That was my TV interface of choice for many years, until I got composite inputs, and or one of those high resolution green screens.  Apple heads knew them well, and I still like them for long sessions on the machines.  Ataris were cool there too, because they could do lots of greys.  I was perfectly happy with the 8 or 16 "colors" I got on the monochrome screen.  In some ways, things were easier, just black to white, no worries.

(A fellow Propeller head is shipping me a nice high resolution Amber one.  It will get connected to the Atari to confirm some high-res graphics pixel tricks I've had bouncing around in my head, and on the Apple, display 80 columns proper.  Can't wait, but I still want an old Apple Monitor /// because I ran my Atari on it a lot, and miss that.)

Edited by potatohead, Tue Apr 24, 2012 5:57 AM.

[atarixle]

Quote

What's so fantastic about Atari 8 bitters?

It's the feeling, how you discover the system. Discovering the BASIC and the POKE/PEEKs is better than any game written on it.

It's the smell of the new machine (yes, it still smells like new).

And it's the fact, that this little machine from 30-20 yearg ago still brings together foreign people from accross the world to speak, play, party together on so many meetings.

[Ransom]

What's so fantastic about them?  I guess it depends on your perspective.  From mine, they're well-designed machines that offer some excellent gaming opportunities and a fun programming environment.  Not to mention the distinctive Pokey sound and the way Antic and GTIA form the display.  The software's also very cool in retrospect.  What other computer manufacturer was putting out something like the Educational System series, or the foreign language series?  Not to mention all the financial programs.  (I'm talking about first-party stuff here; I know all kinds of stuff was available for the others. I just don't know of any other that published so much good quality educational material under their own name.)  To totally geek out, I particularly like the software packaging they used during the Warner era.  Really top-quality stuff.  8.5" X 11", three-hole-punched manuals printed on glossy paper.  Metal cartridges.  Three-hole-punched, heavy cardboard diskette holders.  Elaborate (expensive) boxes with whacky imagery.  Great stuff.

I'm also a fan of Apple ]['s, by the way, but the Atari 8-bit was my first and I still appreciate the built-in capabilities of the machine.  To this day there's no other machine I'd rather sit down at to write an arcade-style game.  I wish it had native 80-column support, though.

Edited to add: Oh, oh!  I forgot one of the coolest advantages Atari has over all the rest.  And that was that Atari had a terrible inventory tracking system and ended up with warehouses full of great hardware and software.  Which means you can still easily get lots of stuff brand new today (including replacement parts).  I don't know of any other system for which that's true.

[Bryan]

potatohead, on Tue Apr 24, 2012 5:52 AM, said:

Yes.  Honestly, the Apple has a first class looking signal too.  I had a C64 for a while, and I thought it looked pretty great on composite.  Never did use it with RF.  It does have color fringing though, due to it's full use of the NTSC signal.

The Apple's video always bugged me. It's actually the video circuit's crudeness that leads to the color problems. Woz was good at finding the simplest possible way of making things work, and he discovered that monochrome pixels appeared in different colors if they were shifted slightly left and right (what Atari folk call artifacting). So, the simplest way to get color was to make a pattern of on-off pixels and add a programmable delay. Because there was no real color signal, there was no way to get nice clear text on a color monitor. You had to have obnoxious orange/green text or get the green monitor (which oddly seemed to be the monitor of choice from the Apple II users I've known). It's the same thing with the Apple's sound. Steve discovered you could make sound effects by connecting a single bit to a speaker cone and running the CPU in timing loops. It's simple but it isn't very friendly. I appreciate that Apple was a terrific company (which is how they survived this long) but the Apple II was defined by its lack of features more than anything. The main exception was the slots but no one could produce a TV-connected device and have the kind of slots Apple did (due to specific FCC rules). Atari tried and ended up having to encase the slots in cast aluminum. TI apparently spent a lot of money trying to get FCC approval for slots. So, the fact that Apple didn't target the TV set sort of puts them in a different class of device.

Another factor is that Apple didn't start building computers with a large R&D budget like everyone else, so initially their designs had to be made from off-the-shelf TTL chips rather than custom VLSI's which allow circuits an order of magnitude larger.  Of course, the Woz disk interface is legendary for its speed so sometimes simplicity works in your favor.

[Goochman]

For me the 800 was awesome due to what any kid could do with it.  The Basic out of the box was easy enough to produce sounds and graphics.  A little more investment and you could easily produce something cool to a kid at that time.  I started many game ideas in basic back then and even finished a few - it started a career for me.

The Apple was not as accessible and the C64 just came out when I got my 800.  The C64 wasnt as accessible for a Basic programmer IMHO either.

The games and utilities were great on the 800 - I only wish it wouldve taken the place the C64 did but we cant change history here

[Grevle]

Well the Atari 8-bits is part of the 80's History and Culture, my first Computer was a Atari 400 and i liked the games Like Star raiders and Ms paman and Missile command and
Centipede , And it was my introduction to Basic programming. I wrote a few games back in the 80's , sadly i lost the code to all my old stuff.

Even thoug many of my friends got C64 I like the Atari best, For Many reasons, Had lots of fun Playing and programming Back in the day, very good memories

[Tinman]

Heaven/TQA, on Tue Apr 24, 2012 2:42 AM, said:

- Joust+Donkey Kong (first played on a mate's 600xl on Cart) and I thought they kick ass
- Star Raiders, too (but I was more into Star Master on the 2600)

Starmaster pales in comparison to the original Star Raiders, in my opinion.  That said, it's one of my two favorite games on the 2600 (the other being Adventure).  So, while not up to Star Raiders, it's still one VERY good game, and better, I think, than the 2600 version of Star Raiders.

[potatohead]

Oh, I agree about Apples and artifacting.  I like color done that way, being an NTSC bunny at heart.  (still don't know too much about PAL, but am learning)  The answer on text was to either kill the color on a text only screen.  Worked great.  Or, fat pixel text on the graphics screen...  Most people went with the Apple char set, and that looked crappy.  I would just run the monitor low color saturation and deal...  +1 Atari there, if anything for the nice blue and white, which I can still look at all day long, and do.

The disks on Apple were fab.  Loved 'em, and generally thought the Atari ones less capable and slow, but...  the little beeps were useful.  My first crack of Ultima ][ was to count 23 beeps in, or maybe it was 19...  then open the door, wait for the SIO fail, then close it, game on!!  They only checked for an error, not a specific error...    So, in that way, Atari disks were awesome, because that little trick would work on a number of titles.  Easy cheezy, copy 'em with DOS.

Re: arcade:

Yeah, Ataris with all the options made that possible for a kid, and that's the beauty of today!  I've got all three, they are cheap, I can run stuff on 'em, and there are fab tools now.  All good from here on out.

[SIO99]

TMR, on Tue Apr 24, 2012 3:48 AM, said:

SIO99, on Mon Apr 23, 2012 8:21 PM, said:

Are you a double agent from Commodore?

Double agent? No, that'd imply that i make some kind of secret of liking or having twenty five years coding experience with the C64. i've also got seven years programming the Atari 8-bit in machine code and a fairly extensive list of other platforms under my belt, but people here seem to forget that as soon as the C64 is mentioned...

SIO99, on Mon Apr 23, 2012 8:21 PM, said:

This is the first time I've heard of any claim of accessing anything like 63K RAM on a Commodore 64. I could try and sum up what a certain magazine said.

[Snip for brevity]

Short version; never trust a magazine to give you correct technical information without consulting a programmer too. =-)

The only truly tricky space to use is under the I/O - disabling it turns off the VIC-II, SID and I/O registers as well as the colour RAM (which exists outside of the standard 64K, technically a C64 has a little shy of 65K), but you can still write to the screen RAM in that state and the most common use for that area i've seen is graphics data - which has to be somewhere, so might as well be in the space it's a little harder to keep code in.

SIO99, on Mon Apr 23, 2012 8:21 PM, said:

The Sinclair Spectrum 48K had more RAM free to BASIC than the Commodore 64!

No, it has more free RAM for BASIC programs but not to BASIC as a whole. Have a look at the C64's memory map at $c000 to $cfff, that space is available for BASIC to use for storage, data, graphics whatever. 4K on top of the 38K for BASIC programs is 42K.

Oh, and getting back onto the topic at hand; what Heaven said about WSYNC.

Please post a BASIC program which opens a graphics screen on a Commodore 64, clears the screen of any garbage which I think may be there, then draws a line across the screen. Feel free to post an Assembly Language program that does the same thing.


I've done some more research into the numbers of BASIC commands on the Commodore 64, as well as on rival computers and here they are.

Click here for a full list of Commodore 64 BASIC commands (total 71) -

http://www.c64-wiki....hp/C64-Commands

Click here for a full list of Sinclair Spectrum BASIC commands (total 86) -

http://en.wikipedia..../Sinclair_BASIC

Click here for a full list of Amstrad Locomotive BASIC commands (total 165) -

http://cpcwiki.eu/in...ocomotive_BASIC

Click here for a full list of Atari BASIC XL commands (total 82)

http://www.atariarch...ge.php?page=376

Note that it only takes 11 more commands (82 instead of 71) to make a reasonable BASIC dialect. I hope this proves conclusively that Commodore either just didn't care, were too stingy to pay anyone to create a new version of BASIC for the Commodore 64, or BOTH! We'll never know how many would be programmers had their confidence shattered by the Commodore 64. I can't help wondering how or why anyone managed to learn how to program it in 6502 Assembly Language, running on the compatible 6510 CPU. My theory is that some programmers learnt on the excellent Atari 8 bit range of computers, then were also able to put this knowledge to use on the Commodore 64. I read that one British software house hated the Commodore 64 so much, that they programmed games for it using a development kit running on the BBC Micro. Apart from anything else, the Commodore 64 was a revamped version of the Commodore Max games console (which included a keyboard), that it seems only went on sale in Japan. This had two versions of BASIC available, one without the ability to SAVE or LOAD programs, the other with only 2047 bytes free to BASIC! I don't know if any RAM upgrades were available. For more information on this botched pile of crap click on the two links below!

http://en.wikipedia....ore_MAX_Machine

http://www.northnet....or/cbm/max.html

As for me, I think I've been psychologically damaged by trying to program a Commodore 64 and I need hypnotherapy to forget all about it. I hope to buy an Atari 8 bit computer from eBay soon, complete with any storage device, as part of some therapy to get over all this. This year is the 30th anniversary of the Commodore 64 being released, but it's certainly nothing to celebrate. The far more advanced Sinclair Spectrum (86 BASIC commands instead of 71) came out the same year.

[Gunstar]

what do I think is so fantastic about the Atari 8-bit?

It has 15+ graphic and text modes with an unheard of pallette of colors at the time, and the ability to mix those graphic modes on screen with DLI's and later more advanced techniques allowing for many software graphic modes too, allowing many, most, or all of the colors available at various resolutions from 90x96 upto 320x192/200/240 (NTSC). And recently up to 480i!

Even more than 15 graphic modes with the software driven modes. Though I did wait a couple decades for some of those graphic modes to be invented.

Still, 256 colors even at 90x96 interlaced resolution I loved as an artist, compared to most other computers limited to 16 or less colors, even if higher resolution.

I think the 1.79Mhz clock speed was fantastic compared to other 6502 competition.

The custom chips are fantastic.

The look and style of the first two 8-bit generations is fantastic (800 and XL lines, even though my first was an XE).

I'm still amazed on a regular basis at what programmers manage to get the Atari hardware to do, even 30+ years later, getting graphics out of it not even attempted until 16 and 32 bit systems came along. Especially the 3D vector, polygon and raycasting type grapjics.

I'm amazed at Space Harrier and Crownland and Outrun and Tempest Xtreem.

I've continually been amazed with A8 graphics for the last 3 decades.

Edited by Gunstar, Wed Apr 25, 2012 6:44 PM.

[TMR]

SIO99, on Wed Apr 25, 2012 1:07 PM, said:

I've done some more research into the numbers of BASIC commands on the Commodore 64, as well as on rival computers and here they are.

That wasn't really worth doing... i've not defended Commodore BASIC V2 and, just to avoid any confusion, personally i feel it to be utter crap as a BASIC dialect because it lacks features and is dog slow. The only positive thing i've ever had to say about it over the years is that, at the time and for me personally, it was that same crapness that meant i had to learn 6502 to write the programs i wanted to make.

SIO99, on Wed Apr 25, 2012 1:07 PM, said:

We'll never know how many would be programmers had their confidence shattered by the Commodore 64.

Of course we won't no, but at the same time we've absolutely no idea how many potential machine code programmers started out with more powerful BASICs and subsequently didn't move on for their 8-bit of choice because they didn't feel the need either. Or how many more like me were forced into learning machine code because the BASIC was weak, how many skipped BASIC entirely or even if having BASIC in the first place made a difference one way or the other.

All i did was correct details about free memory and so forth before answering your question about what is fantastic about the Atari 8-bits...

[potatohead]

So, the BASIC is fantastic then?  LOL!!

[Bryan]

I think the SIO system was a really clever idea. Nothing could be easier than connecting your new peripheral to the last one you connected. That way, you don't have cable hell fanning out of the console, and you don't need 10 different kinds of cable at your disposal. Of course, SIO has its limitations, which is why PBI was invented. Overall, it was a very user-friendly approach to expansion.

[sack-c0s]

If we're talking BASIC to assembler - this is something Acorn got right on the BBC, and carried over into the 32-bit machines:

10 DIM org 100: REM program ends up in here
20 FOR pass=0 TO 3 STEP 3
30 P%=org
40 [ OPT pass
50 LDA #0
60 STA ...
70 ....
80 Assembler goes here
90 ....
100 ]
110 NEXT pass
120 CALL org

so there was a nice, powerful BASIC there (it scaled so well that in ARMBASIC you could even write fully-fledge RISC OS desktop apps) so you didn't have to leave basic, but at the same time there were no obstacles preventing you learning 6502/ARM. The other bonus is that some folks didn't bother saving out the assembled code and shipped the BASIC that compiled and called the resulting code, so you had a form of open source as a reference.

I myself did benefit from the 'all the convenience of assembler with half the speed of BASIC' that commodore BASIC V2 gave. V3.5 was nicer on the C16/plus4 though - graphics and sound commands and a machinecode monitor.

[deathtrappomegranate]

sack-c0s, on Thu Apr 26, 2012 4:12 AM, said:

If we're talking BASIC to assembler - this is something Acorn got right on the BBC, and carried over into the 32-bit machines:

Yes, it may be slightly off-topic, but the BBC's in-line assembler was a great feature in what was already an excellent version of BASIC.

[potatohead]

That's damn cool.

[SIO99]

I think they're so fantastic for the following reasons.

Atari took a lot of trouble in having a suitable BASIC written for the original Atari 400 and 800 computers, rebelled against Microsoft BASIC standards, but then even updated it to get rid of bugs, as well as adding more commands for the XL series. The Commodore 64 came with a BASIC not designed for the Commodore 64 at all, but for the earlier PET computers with no colour, graphics or sound commands!

They designed custom sound and graphics chips, working with the CTIA or GTIA display chip, enabling more colours to be used than on any other 8 bit computer at the time. It took several years before any other 8 bit computers had a similar range of colours, namely MSX2, and the Elan Enterprise. I don't think any other computer at the time had 4 channel sound, only 3 channels at most.

They're a relatively simple system to program, compared with later and current computers and games consoles. The BASIC has commands for controlling almost all facilities, and the 6502 CPU has a fairly simple type of Assembly Language, containing only 56 instructions, most of which don't seem to be used that often.

Current computers running Operating Systems such as MS Windows, Mac OS, and even Linux OS seem to make programming anything a lot more complicated. Some early pioneers have expressed their dislike of the operating systems and drivers getting in the way of writing programs. A new type of computer designed to be cheap and to encourage people to learn programming is called the Raspberry Pi. At the moment, demand for this is outstripping supply, but it either comes with a few programming languages installed, or you can download and install them from the Internet in a special package designed for the Raspberry Pi. These include Brandy BASIC (a BBC BASIC clone), Ruby, and Python, all running under a version of Linux OS. It remains to be seen how easy or difficult this computer will be to program. I'd like to buy one. I usually use Linux OS myself.

[TMR]

SIO99, on Thu Apr 26, 2012 10:46 AM, said:

Atari took a lot of trouble in having a suitable BASIC written for the original Atari 400 and 800 computers, rebelled against Microsoft BASIC standards, but then even updated it to get rid of bugs, as well as adding more commands for the XL series. The Commodore 64 came with a BASIC not designed for the Commodore 64 at all, but for the earlier PET computers with no colour, graphics or sound commands!

No need to bring the C64 up again when talking about the Atari 8-bit...

i'm not sure about the idea of Atari BASIC being some kind of rebellion against Microsoft, if Wikipedia and a few other things i've read previously are right, Atari approached Microsoft first and a version of MS BASIC for the Atari 8-bit series was started but aborted because it wouldn't fit into 8K of ROM at least in the timescale they needed, so Atari had to look elsewhere.

They later published MS BASIC on cartridge and disk as Atari Microsoft BASIC, which lends some credibility to that story that Microsoft were their first choice.

SIO99, on Thu Apr 26, 2012 10:46 AM, said:

A new type of computer designed to be cheap and to encourage people to learn programming is called the Raspberry Pi.

It's probably best to assume that most people here are up to speed with things like the RasPi (or indeed programming on recent operating systems) - i believe a few folks have been considering fun things to do with it and an A8 already... =-)

[JamesD]

potatohead, on Mon Apr 23, 2012 1:35 PM, said:

Some stuff I think is awesome:

1.  I really liked Atari Basic.  It was a non-Microsoft variant, and it could do some great tricks!  One of those was boolean operators in expressions:

50 x = x + ((Y < 50)*5)

Y is compared to 50, and if less, the expression evaluates to "1", which is "true", which is then multiplied by 5, finally the product of that was added to x.

30 IF (y < 50) THEN X = X + 5

That's basically the same thing, done in ordinary BASIC terms.

Actually, other BASICs can do the same thing but TRUE is 0 and -1 is FALSE.

[JamesD]

TMR, on Tue Apr 24, 2012 3:57 AM, said:

SIO99, on Mon Apr 23, 2012 10:15 PM, said:

I never studied 6502 Assembly Language until recently, only Z80 and 68000. I now see that it's more simple than Z80 Assembly Language, but I studied a Z80 Assembler course which criticised the 6502 for having so few registers.

Most Z80 programmers look at the 6502 like that, but the actual situation is a little more complicated; with the Z80, a register pair has to be used as pointers to a location in RAM so it's possible to run out of registers quite quickly if accessing multiple locations in one pass. With the 6502, the registers don't point at addresses in that way and instead two bytes of the zeropage (the first page of memory, which can be addressed faster than the rest of it) take care of the address and the registers are used for moving data between points and offsets from those addresses.

While that is somewhat true, my experience has been that Z80 code is slightly smaller than 6502 code, mostly due to the lack of 16 bit support in the 6502.
To compensate for that shortcoming, you end up having to use Page 0 a lot and run out of space on page zero.  Then your code needs extra instructions to move things in and out of Page 0.
The 6502 also has a very small hardware stack which makes some tasks a lot more complex.
But then 6502 instructions take fewer clock cycles.
It's a trade off.

If you guys want to compare CPUs, Motorola's 6803 and 6809 require a lot less code than the Z80 or 6502.
The 6803 supports Page 0 and 16 bits.  The advanced addressing modes of the 6502 are missing but they aren't required for most things.  The single address register is it's biggest shortcoming.
The 6809 has so much more I wouldn't know where to begin.

I really don't see the 6502 as one of the great features of the Atari except possibly that it made it easier to port existing code to.

I think the big thing was how much it offered and when it offered it.  Sprites, sound, lots of colors, joystick interfaces, coprocessor, faster CPU... it was a leap in technology over other home computers at the time of it's release.  Later sprites were easier to work with, sound chips gained new features, etc... but the basis of all things than made computers great for years were there and before anyone else had them.

[Gunstar]

Bryan, on Wed Apr 25, 2012 7:20 PM, said:

I think the SIO system was a really clever idea. Nothing could be easier than connecting your new peripheral to the last one you connected. That way, you don't have cable hell fanning out of the console, and you don't need 10 different kinds of cable at your disposal. Of course, SIO has its limitations, which is why PBI was invented. Overall, it was a very user-friendly approach to expansion.

I agree with that, SIO was like today's USB in many ways, just plug and play. But, though I lack the knowledge of Commodore that I have with Atari, it seems to me that Commodores serial lines worked essentially the same way, with daisy-chaining, so it's not entirely unique to Atari. Is Atari SIO better than Commodore serial? Anyone?

Until usb, PC's were a different plug for every different device just about, which I always hated. Not to mention drivers for everything. Atari smart peripherials were light-years better.


It certainly was better than Texas Instruments solution with the 99/4A line, where they just attach the next device to the side of the previous one and end up with a system 10 feet wide! LOL!

Edited by Gunstar, Thu Apr 26, 2012 2:26 PM.

[JamesD]

SIO99, on Wed Apr 25, 2012 1:07 PM, said:

I've done some more research into the numbers of BASIC commands on the Commodore 64, as well as on rival computers and here they are.

Click here for a full list of Commodore 64 BASIC commands (total 71) -

http://www.c64-wiki....hp/C64-Commands

Click here for a full list of Sinclair Spectrum BASIC commands (total 86) -

http://en.wikipedia..../Sinclair_BASIC

Click here for a full list of Amstrad Locomotive BASIC commands (total 165) -

http://cpcwiki.eu/in...ocomotive_BASIC

Click here for a full list of Atari BASIC XL commands (total 82)

http://www.atariarch...ge.php?page=376

Note that it only takes 11 more commands (82 instead of 71) to make a reasonable BASIC dialect. I hope this proves conclusively that Commodore either just didn't care, were too stingy to pay anyone to create a new version of BASIC for the Commodore 64, or BOTH! We'll never know how many would be programmers had their confidence shattered by the Commodore 64. I can't help wondering how or why anyone managed to learn how to program it in 6502 Assembly Language, running on the compatible 6510 CPU. My theory is that some programmers learnt on the excellent Atari 8 bit range of computers, then were also able to put this knowledge to use on the Commodore 64. I read that one British software house hated the Commodore 64 so much, that they programmed games for it using a development kit running on the BBC Micro. Apart from anything else, the Commodore 64 was a revamped version of the Commodore Max games console (which included a keyboard), that it seems only went on sale in Japan. This had two versions of BASIC available, one without the ability to SAVE or LOAD programs, the other with only 2047 bytes free to BASIC! I don't know if any RAM upgrades were available. For more information on this botched pile of crap click on the two links below!

First of all, starting in 1984, Commodore sold a Basic Upgrade Cart for the C64 called Simon's Basic that added 91 additional commands to C64 BASIC.  If you wanted or needed more commands, they were certainly available.

Second, your statement about a "reasonable BASIC dialect" is opinion.  
Some magazines regularly carried programs for both machines and the C64's BASIC seemed up to the task.
While some things had to be done with POKEs or machine language, the same can be said about Atari BASIC.
Try moving an Atari Player sprite image up and down quickly, or make it animate without machine language.  Those things could be done fast in C64 BASIC just POKEs.
Face it, all machines from that time had their own advantages and disadvantages.
If you spent much time programming a machine, you learned the tricks for that machine.
To this day I still remember some of the ROM CALL addresses for Applesoft BASIC. (CALL -151 for example)