Atari v Commodore

[popmilo]

@Atariksi:

Correct me, but do you do something else while playing samples and displaying pictures ?

Are you grabing sound and image info from data streamed on serial port ?

How much data is it and how does it work ?

That would make it even more difficult on C64...

 

Yeah, I am buffering the data from joystick port into a queue in the background. It's not a serial port, although that is also used during boot-up. It's 11025 nibbles/second for audio and 8000 bytes per picture. Pictures are lower priority so maintain audio playback continuously and put up images in the background as fast as possible.

Let me see if I understood it correct:

1. You get 8000 bytes from PC across joystick port cable (Pc sends data over parallel port)

2. You display image that those 8000 bytes represent.

3. Start streaming audio from PC at 11025 nibbles/second

4. In interupt (11025 times a second) you receive nible and put it in buffer and you put sample value to pokey audio out.

 

Are receiving and playing sample in same interupt (or maybe not at all in interupt) ?

How do you synchronize PC send routine and Atari receive ?

[Jetboot Jack]

The really sad thing about this thread is that when ANYONE with ANY actual experience of making games (and no not just ONE game, once, 20 years ago) expresses their opinion the idiot fanboys shout them down. With random unproven technical theories, and NO proof.

 

I love the A8, I had one from the start of the 80's YEARS before the C64 came out, I ENJOYED the system, it was/is great - with MANY great games...

 

DO I care there are games on both systems where the C64 version has more colors, no, IF I WANTED THOSE GAMES I WOULD HAVE BOUGHT A C64 - it was very cheap!!!!

 

All this comparison is meaningless, the A8 is a OLDER hardware design, that was a really great one, and those us who owned one in the early 80's liked them then and still do.

 

But please stop fighting, respect people who have actually made something and demonstrated their skills, feel free to disagree, but unless you can actually show (in code and pixels) why they are wrong, stop it...

 

sTeVE

Edited September 13, 2009 by Jetboot Jack

[emkay]

DO I care there are games on both systems where the C64 version has more colors, no, IF I WANTED THOSE GAMES I WOULD HAVE BOUGHT A C64 - it was very cheap!!!!

 

Right. But there is one thing that's getting in the way

It's when you know that any other machine could have done a better job for that game.... you get horrible toe nail rolling , but you don't see a cause for buying the C64.

You only think about nailing this thingy onto the next wall, if you get one at that moment.

[emkay]

did i say anything about the technical specs of the machine? NO.

 

 

No, but you even do not care about it here. I told you that I built the water on some colour floating... that's all. Please don't blame ME for Your own failures, thanks.

 

 

and for someone who it appears has done fck all on their super machine of choice (with the exception of a truly fcking awful Fist tune?) in the last 25 years it does make me smile that u can criticize anyone elses efforts

 

25 years? Done all? How?

 

To have done all in the last 30 years on the Atari, it was necessary to know all about this machine. Only then, coders can think about it and bind it into their project BEFORE they started it. And, well, there still was the "market" that changed everything, after C64 got all attention.

Just things like

 

bad 3D games

better scrolling games

music got limited to 3 channels

a.s.o...

 

we got thankfully by the C64, it's usership , and the market ...

 

The A8 only got some games, the C64 cannot reach after endless "optimisation" were done, to compete with the A8.

Rescue on Fractalus, Koronis Rift, Ballblazer, The Eidolon. It's just that some already good coders got a huge amount of money for producing them.

Well, after that money was gone, they even decided NOT to realease other finished games (Labyrith f.e.) .... but, the chance of making big money with the C64 made further titles possible there...

 

IF the A8 was supported better by Atari, the knowledgebase, and the end users, we would have approached a fully different era of home computers in the 80's, and the "rule" of computer's hardware growth got never interrupted.

Perhaps, people would have bought the C64 for the good sprite games and to make music with the SID. But the main game line would have stand "Ego/3D".

[STE'86]

i think u are being purposefully obtuse again

 

i will spell it out:

 

I dont think YOU, who have done NOTHING for your machine in the last 25 years except post bullshit on this forum have any kind of right to critisize ANYONE who has actually produced anything for real.

 

now is that clear enuf? i am not talking in generalisations about the a8 world or the 64 world i am talking about your PERSONAL contribution to this a8 world.

 

so either please show me what u have done to help it along or stop posting to me.

 

Steve

[TMR]

and for someone who it appears has done fck all on their super machine of choice (with the exception of a truly fcking awful Fist tune?) in the last 25 years it does make me smile that u can criticize anyone elses efforts

 

25 years? Done all? How?

 

To have done all in the last 30 years on the Atari, it was necessary to know all about this machine. Only then, coders can think about it and bind it into their project BEFORE they started it.

 

He was talking about what you've personally done, emkay...

 

Perhaps, people would have bought the C64 for the good sprite games and to make music with the SID. But the main game line would have stand "Ego/3D".

 

So there's another reason for me to like the C64 right there! Give me a 2D scrolling shoot 'em up every time over 3D, regardless of platform, era or indeed anything else.

[carmel_andrews]

I think we are becoming a LOT MORE like the jaguar community/market...If there is a god out there save us from this damnation

 

Let's not try and compete with the jaguar community/market to see which one can tear itself apart first eh, lets at least respect and appreciate what anyone here has contributed to either atariage or the atari 8bit community

 

Btw, nice to see some commodore 64 converts as well...like ste and pete d (any more like you that want to come to the right side of the force)

Edited September 13, 2009 by carmel_andrews

[atariksi]

I wasn't really looking for cycle-exact coding just no badlines. I can live with a few cycles here and there from interrupt. Perhaps, if I set up a 160*200 sprite layer w/screen off.

 

That still gets you ten chunks of sprite handling interrupt and an eleventh to jiggle the lower border to enable hyperscreen (just having the screen turned off will also hide the sprites, the border has the highest priority of anything on the C64), but if you run the sample player on NMI it'll take priority in those cases.

 

I thought it was suggested in post #8111 that you can disable screen and have sprites enabled. Anyway, how about writing to some register every audio IRQ to prevent a badline or swap sprite ram area completely since sprite positions are fixed (assuming I can have sprites w/o screen area).

[andym00]

I thought it was suggested in post #8111 that you can disable screen and have sprites enabled. Anyway, how about writing to some register every audio IRQ to prevent a badline or swap sprite ram area completely since sprite positions are fixed (assuming I can have sprites w/o screen area).

 

He is agreeing I think, just there's two ways to do it, top of the the screen or bottom of the screen

The jist of it is this..

Set an interrupt on line $2F and disable the screen.. $D011:[4] = 0

Interrupt again on or after $31 (up to $33) enable the screen.. $D011:[4] =1

The top and bottom borders will vanish as well, and there'll be no screen DMA, only sprite DMA (if they're enabled), and the only displayed screen data (apart from sprites) will be the idle byte from VIC which is located at the top byte of the VIC bank.. It's one byte that VIC fetches when idle and repeatedly displays it.. You can fiddle with this to do some funky effects on the screen.. The only way badlines can occur is simply if the display enable bit is set for at least one cycle on line $30.. Stop that occuring, but enable the screen again before it's started to be drawn and voila, the magical 'HyperScreen' as it's called..

It's the easiest way by miles for a display with no badlines, if you can live with sprites only..

Edited September 13, 2009 by andym00

[atariksi]

@Atariksi:

Correct me, but do you do something else while playing samples and displaying pictures ?

Are you grabing sound and image info from data streamed on serial port ?

How much data is it and how does it work ?

That would make it even more difficult on C64...

 

Yeah, I am buffering the data from joystick port into a queue in the background. It's not a serial port, although that is also used during boot-up. It's 11025 nibbles/second for audio and 8000 bytes per picture. Pictures are lower priority so maintain audio playback continuously and put up images in the background as fast as possible.

Let me see if I understood it correct:

1. You get 8000 bytes from PC across joystick port cable (Pc sends data over parallel port)

2. You display image that those 8000 bytes represent.

3. Start streaming audio from PC at 11025 nibbles/second

4. In interupt (11025 times a second) you receive nible and put it in buffer and you put sample value to pokey audio out.

 

Are receiving and playing sample in same interupt (or maybe not at all in interupt) ?

How do you synchronize PC send routine and Atari receive ?

 

Everything is streamed-- the video (bunch of frames at 8000 bytes each), the audio, and in some cases the code (for loading extra routines if needed). However, audio is highest priority. PC send and Atari receive is not synchronized because PC has to read from CDROM which is slower than playing back a sample of audio on Atari. So audio gets queued until it's time to be played by the Audio IRQ.

[NorthPole(heeHAW)]

Hello!

 

I'm new to this thread and feel rather shy, may I speak in the same language but on a different level?

 

 

%74%68%65%20%61%74%61%72%69%20%76%73%20%43%36%34%20%74%68%72%65%61%64%20%69%73%20%6c%6f%61%64%73%20%65%6e%74%65%72%74%61%69%6e%69%6e%67%2e%2e%2e%2e%20%74%6f%20%61%20%70%6f%69%6e%74%2e%2e%2e%2e%2e%20%42%75%74%2c%20%69%74%27%73%20%67%65%74%74%69%6e%67%20%6c%69%6b%65%20%61%20%62%61%64%20%72%75%6e%20%6f%66%20%4e%65%69%67%68%62%6f%72%73%2e%2e%2e%2e%20%53%6f%20%74%6f%20%4b%69%6c%6c%20%74%68%69%73%20%74%68%72%65%61%64%20%61%6e%64%20%61%6c%6c%20%69%74%73%20%68%79%70%6f%63%72%69%74%65%73%2e%2e%2e%2e%57%65%20%6e%65%65%64%20%74%6f%20%64%6f%20%74%68%69%73%2e%2e%2e%2e%20%41%49%4d%3a%20%20%54%68%65%20%66%69%72%73%74%20%6f%6e%65%20%74%6f%20%70%72%6f%76%65%20%74%68%65%69%72%20%70%6f%69%6e%74%20%61%62%6f%75%74%20%68%61%72%64%77%61%72%65%20%73%68%6f%75%6c%64%20%64%6f%20%74%68%65%20%66%6f%6c%6c%6f%77%69%6e%67%2e%a%a%43%6f%64%65%20%69%74%2e%a%a%50%6f%72%74%20%69%74%20%a%a%52%65%6c%65%61%73%65%20%69%74%2e%a%a%a

 

 

Regards.

 

A

[Bryan]

the atari vs C64 thread is loads entertaining.... to a point..... But' it's getting like a bad run of Neighbors.... So to Kill this thread and all its hypocrites....We need to do this.... AIM: The first one to prove their point about hardware should do the following.??Code it.??Port it ??Release it.???

[popmilo]

Everything is streamed-- the video (bunch of frames at 8000 bytes each), the audio, and in some cases the code (for loading extra routines if needed). However, audio is highest priority. PC send and Atari receive is not synchronized because PC has to read from CDROM which is slower than playing back a sample of audio on Atari. So audio gets queued until it's time to be played by the Audio IRQ.

So you start interupts on Atari at 11025 Hz and just prey to gods that pc will send data at same rate ?

No sync pulse, no start stop bits - nothing ?

I guess its not a big deal if you skip one audio sample or play one twice...

Just a stream of nibles ? Or sometimes 4bits, sometimes 8 bits ?

I guess you have some markers like few specific bytes to decide if incoming data is picture or sound or program ?

 

If you disable screen and leave only sprites you still have to multiplex them (that is not such a problem - you have one LDA and 9 STA to do in 21 scanlines) but they do steal 17 cpu cycles every scanline from CPU.

Normal scan line, 8 sprites
0         1         2         3         4         5         6
012345678901234567890123456789012345678901234567890123456789012 cycles
ggggggggggggggggggggggggggggggggggggggggrrrrr  pspspspspspspsps phi-1 VIC
                                              ssssssssssssssss phi-2 VIC
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxXXX                 phi-2 6510
46-49 cycles available

g= grafix data fetch (character images or graphics data)
r= refresh
p= sprite image pointer fetch
c= character and color CODE fetch during a bad scan line
s= sprite data fetch
x= processor executing instructions
X= processor executing an instruction, bus request pending

So instead of 40 cycles stolen every 8th line, you get 16-17 cycles stolen every line

and sprites can cover only 96 4color multicolor pixel wide area... 24 chars...

Oo you could get same resolution as GTIA with 7 sprites double expanded in x direction but only in 4 colors.

 

25x40 cycles stolen seams better than 160x16 to me...

[emkay]

i think u are being purposefully obtuse again

 

i will spell it out:

 

I dont think YOU, who have done NOTHING for your machine in the last 25 years except post bullshit on this forum have any kind of right to critisize ANYONE who has actually produced anything for real.

 

 

Regards

 

At that moment, when you get money for your production, you lose all right to protect it from an official customer statement.

 

I have done many stuff, but not all outlived til today.

One is the game "Admirandus" , one is the "networking" game "XL-ST Schiffeversenken" , several Basic games and graphics converters, which helped to win a contest once in the 80s. And so on.... but those projects were done in my spare time, between doing my daily work and some relaxing from it. If I intended to make money, I would have changed to the ST or AMIGA. But, after losing any fun with programming, I dropped it all. My real life has nothing to do with coding, making music or doing graphics....

 

Just for information.

 

now is that clear enuf? i am not talking in generalisations about the a8 world or the 64 world i am talking about your PERSONAL contribution to this a8 world.

 

so either please show me what u have done to help it along or stop posting to me.

 

Steve

 

 

[carmel_andrews]

the atari vs C64 thread is loads entertaining.... to a point..... But' it's getting like a bad run of Neighbors.... So to Kill this thread and all its hypocrites....We need to do this.... AIM: The first one to prove their point about hardware should do the following.??Code it.??Port it ??Release it.???

 

 

 

 

 

 

 

Did you cheat and use google translate....what language was that

[TMR]

I thought it was suggested in post #8111 that you can disable screen and have sprites enabled. Anyway, how about writing to some register every audio IRQ to prevent a badline or swap sprite ram area completely since sprite positions are fixed (assuming I can have sprites w/o screen area).

 

He is agreeing I think, just there's two ways to do it, top of the the screen or bottom of the screen

 

Yeah, i've always done Hyperscreen as i'd do a normal upper/lower border routine down at scanline $f9 but both work in the same way.

 

Anyway, how about writing to some register every audio IRQ to prevent a badline or swap sprite ram area completely since sprite positions are fixed (assuming I can have sprites w/o screen area).

 

To change the sprite definitions in a hurry you just have to use what i was talking about previously, have multiple screen RAMs in memory with the data pointers at the end pointing to your rows of sprites and simply change where the screen is pointing within the current 16K bank; one LDA / STA pair gets you eight sprites changed instantly (and to clarify, yes it still works when Hyperscreen is running and the screen RAM is being ignored for the actual display).

[TMR]

At that moment, when you get money for your production, you lose all right to protect it from an official customer statement.

 

No that's utter rubbish because he doesn't, certainly not from someone who wouldn't have actually been a customer (unless you're telling me you paid money for Codemasters games on the C128 you owned for was it fourteen days?) and i'll say it again just for emphasis, a lot of what Ste did in the past and his work on Fist now was and is for the love of it and not for money. It's just that someone decided he was good and that they'd pay him to do more. Is all this bitterness on your part because nobody offered you a job back then or something?

[TMR]

Did you cheat and use google translate....what language was that

 

It wasn't a language, those are character codes and the text was already in English.

[oky2000]

As I have always said there can be no 100% slamdunk winner on either side. Which is why this thread will end.

 

BOTH machines have compromises and yes BOTH machines could have been improved. If you look at the Commodore 16/+4 TED chipset it is more like the A8 in the features it chooses to include than the C64 eg Faster CPU and 128 colours with huge restrictions on how many are available on screen etc but without the PM graphics...but then the C16 was a budget machine intended initially by Jack Tramiel to be sold for $70-100 in basic Atari 400 style (ie no proper keyboard).

 

As for who's point is valid or not really should come down to being able to prove a point with some working code their point, whether you have written 0 or 100 games on either machine. There are plenty of games on both that were produced using less then 90% of that machines ability. We can all wax lyrical about things that theoretically are possible but in reality they may not be suitable for use in a game with realtime user input so might only be good for demos.

[Gury]

Isn't the biggest problem with Draconus the drop in resolution - rather than the colour choice. Having to run software sprites rather than H/W shows the difference between the two systems more than anything else.

 

It doesn't show the difference between the two systems, but shows a difference in implementation of the game.

This talk about implementations of Draconus game on both platforms can go on and on forever. The fact is, as I am concerned, the game on A8 rocks. The title screen music is excellent and gameplay is perfect. Those days in my childhood I was always amazed by the graphics and the sounds of this game. Just my thought.

[TMR]

This talk about implementations of Draconus game on both platforms can go on and on forever. The fact is, as I am concerned, the game on A8 rocks. The title screen music is excellent and gameplay is perfect.

 

The discussion came from a comparison and, since both games play the same, seem to rely on pretty much the same attack pattern data and code and have the same notes in the music, those are moot points past the subjective personal preference for POKEY or SID and the only difference is colour use (cyan highlights versus purple mountains) and the lower resolution on the A8. Now me, i'm perfectly happy to play either version of Draconus (well okay, i don't particularly enjoy it as a game on either so there's not one version that i prefer, but the same arguments are true of Zybex and i enjoy that as a gamer) but if emkay is going to talk rot about "realism" and the cyan highlights of the C64 version when the A8 has bright purple mountains and totally cyan brickwork, i'm going to seriously question his idea of reailty and possibly his eyesight to boot.

 

What bugs me a little as a coder is the flak that Brian Jobling's code is actually taking from A8 people, it really isn't as simple a piece of work as some seem to feel and converting it up to a higher resolution would probably cause issues in a similar way that my mocked bitmap mode C64 version would.

Edited September 14, 2009 by TMR

[PeteD]

Just waiting for the next round of god awful Pics to ruin the tranquillity...

 

 

Pete

[NorthPole(heeHAW)]

So who's gonna do me a lovely demo?

[carmel_andrews]

Just waiting for the next round of god awful Pics to ruin the tranquillity...

 

 

Pete

 

 

 

 

 

 

Just for you Pete

 

 

Commodore Girls

 

 

http://www.dickestel.com/images/expo305.jpg

 

 

Atari girls

 

http://www.e3girls.com/subview.cfm?photoid=1288&type=companyyear&query=47&company=47&year=6

[PeteD]

I wouldn't say any of those are god awful

 

 

Pete