Crazyace

Does that mean it's not possible? I was hoping that you'd be a bit more helpful - I spent more time programming on the 8 bit ( I had a 64 , but the only game I wrote was a graphic adventure - and I wrote it using Mac65, and transferred to the c64 via a joystick to par port cable .. It wasn't something that stretched the technical capabilities of the c64 much ) On the a8 the left/right border is way smaller - and on NTSC it may actually be overscanned already, so it's not so obvious as on the c64. I should finish my pacman demo - it would be so much easier on the C64 because of the amazing sprite capabilities - but the playfield is overscanned fully on the a8

Yes, the C64.. I had a look around, and most of the comments ( in C= hacking for example ) just talk about the border disappearing and the ability to put sprites there - I guess that it must be possible - as there are games with control panels in the bottom border, but I dont really want to waste too much time researching it

Actually I'll show my ignorance of the c64 here - when you open the borders, is there still character data being fetched in the borders?

they still need more effort that on the 8bit atari. I never played around with the c64 that much - does scrolling still work with the borders removed?

I think overscan is one area where the 8 bit wins - it takes a lot of effort to open the borders on the C64, on the Atari it's quite easy ( even trivial ) - and if you're using horizontal scrolling there's no real point not using the wide playfield as the data is fetched anyway.

Not this again. Sorry, but they already had the original VIC I to look at for improvement. Garak The designers stated that they looked at the Atari sprite system ( and the TI 99 as well ) - as the VIC I had no sprites anything would have been an improvement. I took it as a given that they also looked at the VIC I when designing the sequel - the seperate colour memory was already a feature for that chip.

I think he was thinking about how to improve on the Atari VCS graphics.. and he succeeded there. He was probally also looking at the Apple II ( with a wierd, 6 colour high res based on 7 bits high res and artifacting, along with an 8 bit to push the phase further ) - but I'm glad he didn't go for that Again it's 4 years , 1978 Atari 400/800 -> 1982 C64..... in 1986 the Amiga was out, and I think that made the C64 look way more dated than the c64 made the Atari ( It's funny, the Amiga startup began in 1982 )

Ok, that didn't work... trying again...

I quite like the Pacman / Cowboy picture I cant find many 256 colour images on the web , this one comes from a standard jpeg convertor

I love the 8 bit tech - but it's stupid to ignore the fact that the C64 does some things better - After all, the MOS designers looked at the Atari when they designed the VICII chip - and they tried to improve on what they thought were the shortcomings.. I really like this image on the C64 - It's not the most technical, but it's displayed by the C64 without any software efforts at all. I expect it's possible to display it on the Atari, but that would need at lot more cpu time, ( and the use of PM graphics I guess )

However, there still was somebody who did it, including scrolling: (when it is running you can use keys 1,2 or 3 to select/deselect/change demo-features, like turning sprite underlays on/off, etc. Push 'HELP'-console-key for showing description of the keys) Are there 16 background+8 foreground colours per line - I only counted 9 It's nice - but where are the player and enemy sprites - on the c64 you could have 8 multicolour sprites without any difficult programming needed

Seems a little harder than the C64 - where you'd use an inverse character set and extended background to get 16 backgrounds + 4 foreground colours.. - and scrolling might be a bit of a chore I haven't seen any program on the 8 bit that allows that either On the plus side for the 8 bit - the '256' colur GTIA9/11 mode still impresses today - lowres, but true colour in a way that nothing else could match until the Amiga with HAM ( or ST with Spectrum512 , or maybe the MSX2? )

retriggering isn't that practical for players anyway - to retrigger you'd also want to reload data as well as a new x position

It's not possible to retrigger that much. C64 sprites are 192 hires/96 lores pixels wide. That's the equivalent of 24 players! You would have to retrigger players 19 times -> completely impossible. c64 sprites have double width as well - so you can cover the screen with single colour sprites at the same res given by players. - even the Amiga H/W sprites weren't actually that much of an improvement over the C64 Something like this would be difficult to reproduce as well on the 8 bit http://www.youtube.com/watch?v=FcTQarRrTjM...feature=related just because of the number of sprites on a single line ( I think even the NES/SMS versions have some flicker in these situations )

12-bit character is just one mode. I can keep repeating GTIA but that's not the point. In general you have more choices on Atari with graphics modes. We are not only looking at some applications that may take advantage of 12-bit characters but everything that can possibly be done on each machine so all choices have to be taken into account. Just looking at sprite hardware, C64 is superior. Now if you start mixing things up like some are trying to do by claiming C64 has more colors per scanline so it has more colors then I can start mixing DLIs and timer IRQs and claim Atari has more sprites per scanline as well. Why are you claiming C64 HW is way more powerful? GTIA is the strengh of the Atari in the colour sense ( I did mention in the original post about colour range ) I think the C64 sprite h/w is a large portion of the chip - it's actually almost competitive with the NES in someways - it wasn't till the SNES/Megadrive that you could cover a complete scanline with sprites! ( I know you can retrigger the pm graphics - but you'd have to retrigger them a lot before you matched the standard C64 sprites, and there would be difficulties in a game situation ) The colours per scanline is the other improvement - that's the big win from the colour ram. It doesn't really matter if you can get 17 colours per scanline with a software loop ( I can do that with a 2600 )

In HW terms the C64 is way more powerful than the Atari 8 bit - but it did come out four years later ( 1982 vs 1978 ) . In modern terms that's the difference between the Xbox and the Xbox360 You cant argue with the 12 bit character format ( 8+4bit colour ram ) and the far superior sprites. But the Atari does seem to hold it's own quite well - and it trashes the Vic20 ( which was introduced 2 years later ) and still wins out on colour range and 'hires' scrolling. I was thinking that it would have been a 'tiny' change to make the Atari missiles 8 bits wide rather than 2 , and that would have made a major difference to the sprite capabilities.

translate.google.com with auto detect language does a fair job. The keyboard/basic looks interesting

I'll make a demo when I finally finish with the 8 bit pacman demo

PDF would be nice - but it's not a real killer - ( My original copy of Mapping is mouldy - and DeRe is probally worse, as I guess it's still in my mum's loft ) Putting the help on an e-reader would be nice

The supercart has 8k of ram at $4000 as well as the 4k built into the console.. ( The memory space was 16k for ram ) I never used it in code at the time , Chronicles was designed as a 128K rom only game ( 16k code, and 6 banks of 16k for each level + 16k for the shop ) - but there was a lot of wastage. If I finished it today I wouldn't bother compressing it though All the Atari carts are 16k fixed at $c000-$ffff , and a 16k bank switched in at $8000-$bfff ( I switched by writing 0-7 to $8000 ) Do you have the 7800_Devkit pdf? I think it's documented more fully there

It looks like the backdrop is a movie ( or anim streamed from HDD ) - apart from that it looks pretty simple to reproduce on a stock jaguar

It's easy to program for, especially if you've just finished working on some 2600 games

If you know the hardware - then you know the limits quite well.

I had the a8 trackball - it ruled for missile command ( Even the touch tablet wasn't too bad for some games )

All game coders are like illusionists I find one of the things about demos is that way more time is put into a small bit of code than most commercial coders have the luxury for. But the results are there - and sometimes , an effect that appears as a demo first may make it into a game somewhere. Othertimes 'demo' effects are produced in house, and games can be made around them ( Rescue on Fractalus ) Anyway, an extreme situation is still using the H/W - ( isn't scrolling on CV where theres no hw scroll just one extreme situation ) For the 7800 one thing is nice that memory isn't limited - so it would be practical to put in 128 or 256K of rom if it were needed to get some amazing effect... ( As one point - it would be easy to have a game like Xmen vs SF on the 7800 - as the h/w could support massive sprites - the only limitation would be memory )