The Rise and Fall of 6502 Gaming (2020) • Hacker News Board

Re: The Rise and Fall of 6502 Gaming (2020)

#31

Post by OnlyMortal » Wed, Jun 29, 2022, 2:44 PM UTC

satisfice wrote: post #30

NonNefarious wrote: post #19

Earlier quoted context omitted.

Mmmm, I don't think so. The Apple had only blitting, whereas the Atari, Commodore, and TI had hardware sprites. And I have no idea what you mean by "C64 had awkward graphics." It integrated ideas already present in the Atari computers, with some advantages and some disadvantages. Both those platforms utterly crushed the primitive graphics and "sound" available on the Apples, with their hardware sprites, fine scrollin…

It by “blitting” you mean the Apple had a single 6502 chip which could move bytes around, then yes. But it had no dedicated blitting chip like the Amiga had (which I never got to work). The Atari graphics were awkward, too, or so I was told by my boss at the time who did the Atari versions of our products. Good though. What I mean by awkward is just that I was surprised, as someone with no training in computer engine…

The Amiga 500 blitter was nothing to write home about, in my experience. Slow.

But, moving 16bit words was a huge improvement compared to the C64 for obvious reasons.

The one thing the C64 missed was full screen hardware scrolling. I don’t mean the pixel shifting.

I’m aware there’s a clever hack to get full screen scrolling - even at Sonic the Hedgehog rates.

This game leverages that: https://m.youtube.com/watch?v=ldo2ewLBt3Y

Re: The Rise and Fall of 6502 Gaming (2020)

#32

Post by NonNefarious » Wed, Jun 29, 2022, 6:09 PM UTC

NonNefarious wrote: post #19

satisfice wrote: post #9

The article makes it sounds like it was difficult to update the AppleII screen so that there was no flicker. It was not difficult. We had plenty of time. I seem to recall we could flip between two different high res screens and so we drew on the hidden one and then flipped to the other one when the vertical blank interrupt occurred. Also, we rarely had to update the entire screen all at once. Both the Apple and C64 h…

Mmmm, I don't think so. The Apple had only blitting, whereas the Atari, Commodore, and TI had hardware sprites. And I have no idea what you mean by "C64 had awkward graphics." It integrated ideas already present in the Atari computers, with some advantages and some disadvantages. Both those platforms utterly crushed the primitive graphics and "sound" available on the Apples, with their hardware sprites, fine scrollin…

Blitting refers to rewriting bytes, yes. It does not imply dedicated hardware to do so, which is why Apple games flickered.

Calling Atari and Commodore graphics "awkward" in the scenario you describe sounds like laziness in learning and taking advantage of new graphics hardware. The sole "awkward" thing on the Atari was that, for some reason, the sprites were as tall as the screen and therefore the only way to achieve vertical movement of a sprite was indeed to move it through memory. But you could do this even in BASIC by setting the sprite data up in a character string and using the fast string functions to move it.

Both the Atari and Commodore made graphics programming decidedly non-awkward by providing automated collision detection between the sprites, and also with the background. Moving sprites around during screen refresh was common on both platforms. On the Atari, the technique (called a display-list interrupt) could also be used to put 256 colors on the screen at once and simulate multi-color sprites.

An innovative use of display-list interrupts gave rise to this cool effect that was called (by LucasArts if I recall) "altered-perspective scrolling." Check it out here in BallBlazer, a soccer-type game written for the Ataris: https://youtu.be/_tkwWD_BWWQ?t=631

Re: The Rise and Fall of 6502 Gaming (2020)

#33

Post by NonNefarious » Wed, Jun 29, 2022, 6:25 PM UTC

aYsY4dDQ2NrcNzA wrote: post #26

NonNefarious wrote: post #19

Earlier quoted context omitted.

Mmmm, I don't think so. The Apple had only blitting, whereas the Atari, Commodore, and TI had hardware sprites. And I have no idea what you mean by "C64 had awkward graphics." It integrated ideas already present in the Atari computers, with some advantages and some disadvantages. Both those platforms utterly crushed the primitive graphics and "sound" available on the Apples, with their hardware sprites, fine scrollin…

Don’t forget shape tables! https://en.wikipedia.org/wiki/Shape_table

Ugh. When I was in junior high and going to the school library to use the Apples, of course I wanted to write games. I kept asking the teacher how to make moving graphics. Needless to say, nobody knew.

At some point I got clued into shape tables, plotted one out, and then called upon it in a program. It was no faster than a sequence "drawto" statements. At that point, I had my answer: You don't; at least not on an Apple.

Re: The Rise and Fall of 6502 Gaming (2020)

#34

Post by NonNefarious » Wed, Jun 29, 2022, 6:28 PM UTC

tinus_hn wrote: post #28

NonNefarious wrote: post #19

Earlier quoted context omitted.

Mmmm, I don't think so. The Apple had only blitting, whereas the Atari, Commodore, and TI had hardware sprites. And I have no idea what you mean by "C64 had awkward graphics." It integrated ideas already present in the Atari computers, with some advantages and some disadvantages. Both those platforms utterly crushed the primitive graphics and "sound" available on the Apples, with their hardware sprites, fine scrollin…

The scrolling model used on the c64 means you have to copy the entire screen which is difficult to do quickly enough to avoid glitches. In contrast for instance the NES outputs the content of a sliding window on a large buffer so you only have to move the window and draw the newly exposed screen area. That way you can create more dynamic games with the same processor.

I seriously doubt that. This certainly wasn't true on the Atari. The Atari had fine scrolling and no need even to redraw newly exposed areas. The screen was, as you describe, merely a window upon as much memory as you had available.

Because the Ataris and Commodores had redefinable character sets, you could create graphic elements as characters and build huge maps and scroll around them smoothly with ease.

Re: The Rise and Fall of 6502 Gaming (2020)

#35

Post by satisfice » Wed, Jun 29, 2022, 11:22 PM UTC

NonNefarious wrote: post #32

NonNefarious wrote: post #19

Earlier quoted context omitted.

Mmmm, I don't think so. The Apple had only blitting, whereas the Atari, Commodore, and TI had hardware sprites. And I have no idea what you mean by "C64 had awkward graphics." It integrated ideas already present in the Atari computers, with some advantages and some disadvantages. Both those platforms utterly crushed the primitive graphics and "sound" available on the Apples, with their hardware sprites, fine scrollin…

Blitting refers to rewriting bytes, yes. It does not imply dedicated hardware to do so, which is why Apple games flickered. Calling Atari and Commodore graphics "awkward" in the scenario you describe sounds like laziness in learning and taking advantage of new graphics hardware. The sole "awkward" thing on the Atari was that, for some reason, the sprites were as tall as the screen and therefore the only way to achiev…

No, Apple games did not flicker. We used screen swapping to stop that. It's the first lesson I learned as a video game programmer: flicker not allowed.

I don't know what your deal is with the word "awkward." As someone who wrote a lot of games on Apple, C64, and one each on the PC and Amiga, I've earned the right to use whatever innocuous word I want to describe a vague feeling that I have. Mind you, all that more than 35 years ago. Perhaps I am misremembering how non-awkward it all was. I did not do anything with the Atari. I was merely told by my boss and friend Dale Disharoon how strange he found it.

Yes, we liked the C64 collision detection. The main awkwardness about the C64 was, at the time I was first working with it, that it was all undocumented. I just think it's awkward to call information to get the phone number of a writer of a magazine article in Toronto to find out how to work the vertical blank interrupt, since there was no reference manual at that time. The Amiga manuals were full of errors when they first came out.

I suppose I am a lazy learner. As you can read all about in my book about being a high school dropout, published by Simon and Schuster (get your copy in Korean today!). Also see page 60 of this issue of Compute Gazette (https://archive.org/details/1983-11-computegazette/page/n59/...).

Re: The Rise and Fall of 6502 Gaming (2020)

#36

Post by kazinator » Wed, Jun 29, 2022, 11:23 PM UTC

satisfice wrote: post #35

NonNefarious wrote: post #32

Earlier quoted context omitted.

Blitting refers to rewriting bytes, yes. It does not imply dedicated hardware to do so, which is why Apple games flickered. Calling Atari and Commodore graphics "awkward" in the scenario you describe sounds like laziness in learning and taking advantage of new graphics hardware. The sole "awkward" thing on the Atari was that, for some reason, the sprites were as tall as the screen and therefore the only way to achiev…

No, Apple games did not flicker. We used screen swapping to stop that. It's the first lesson I learned as a video game programmer: flicker not allowed. I don't know what your deal is with the word "awkward." As someone who wrote a lot of games on Apple, C64, and one each on the PC and Amiga, I've earned the right to use whatever innocuous word I want to describe a vague feeling that I have. Mind you, all that more th…

Apple II games didn't flicker, but exhibited tearing because there was no indication of the vertical retrace: no I/O pin or interrupt, nothing.

I don't remember a lot either and am searching for this now. It looks like the Apple IIe added a bit at $C019 for detecting vertical retrace, but the II+ and earlier didn't have it.

Re: The Rise and Fall of 6502 Gaming (2020)

#37

Post by tinus_hn » Thu, Jun 30, 2022, 6:32 AM UTC

NonNefarious wrote: post #34

tinus_hn wrote: post #28

Earlier quoted context omitted.

The scrolling model used on the c64 means you have to copy the entire screen which is difficult to do quickly enough to avoid glitches. In contrast for instance the NES outputs the content of a sliding window on a large buffer so you only have to move the window and draw the newly exposed screen area. That way you can create more dynamic games with the same processor.

I seriously doubt that. This certainly wasn't true on the Atari. The Atari had fine scrolling and no need even to redraw newly exposed areas. The screen was, as you describe, merely a window upon as much memory as you had available. Because the Ataris and Commodores had redefinable character sets, you could create graphic elements as characters and build huge maps and scroll around them smoothly with ease.

It’s a 1mhz processor and for scrolling to be smooth you need to move 2k of memory within one frame. That means if you get the timing right you have at most 1 million/60 clock ticks, which is about 16666, to do the scrolling and everything else you need to do.

You really can’t do that ‘with ease’ which is why c64 games typically divide up the screen so the scrolling area is smaller.

Re: The Rise and Fall of 6502 Gaming (2020)

#38

Post by NonNefarious » Sat, Jul 02, 2022, 7:39 AM UTC

satisfice wrote: post #35

NonNefarious wrote: post #32

Earlier quoted context omitted.

Blitting refers to rewriting bytes, yes. It does not imply dedicated hardware to do so, which is why Apple games flickered. Calling Atari and Commodore graphics "awkward" in the scenario you describe sounds like laziness in learning and taking advantage of new graphics hardware. The sole "awkward" thing on the Atari was that, for some reason, the sprites were as tall as the screen and therefore the only way to achiev…

No, Apple games did not flicker. We used screen swapping to stop that. It's the first lesson I learned as a video game programmer: flicker not allowed. I don't know what your deal is with the word "awkward." As someone who wrote a lot of games on Apple, C64, and one each on the PC and Amiga, I've earned the right to use whatever innocuous word I want to describe a vague feeling that I have. Mind you, all that more th…

Apple games flickered and sucked ass. It's time to admit it, bro.

Also: The sound of a planet blowing up on an Apple resembled someone spilling a bowl of pistachio shells.

Re: The Rise and Fall of 6502 Gaming (2020)

#39

Post by NonNefarious » Sat, Jul 02, 2022, 7:41 AM UTC

tinus_hn wrote: post #37

NonNefarious wrote: post #34

Earlier quoted context omitted.

I seriously doubt that. This certainly wasn't true on the Atari. The Atari had fine scrolling and no need even to redraw newly exposed areas. The screen was, as you describe, merely a window upon as much memory as you had available. Because the Ataris and Commodores had redefinable character sets, you could create graphic elements as characters and build huge maps and scroll around them smoothly with ease.

It’s a 1mhz processor and for scrolling to be smooth you need to move 2k of memory within one frame. That means if you get the timing right you have at most 1 million/60 clock ticks, which is about 16666, to do the scrolling and everything else you need to do. You really can’t do that ‘with ease’ which is why c64 games typically divide up the screen so the scrolling area is smaller.

You don't move the memory at all. You move the window. If that's not clear at this point in the discussion (let alone 30 years later) I don't know what to tell you.

Re: The Rise and Fall of 6502 Gaming (2020)

#40

Post by satisfice » Sun, Jul 03, 2022, 7:52 PM UTC

NonNefarious wrote: post #38

satisfice wrote: post #35

Earlier quoted context omitted.

No, Apple games did not flicker. We used screen swapping to stop that. It's the first lesson I learned as a video game programmer: flicker not allowed. I don't know what your deal is with the word "awkward." As someone who wrote a lot of games on Apple, C64, and one each on the PC and Amiga, I've earned the right to use whatever innocuous word I want to describe a vague feeling that I have. Mind you, all that more th…

Apple games flickered and sucked ass. It's time to admit it, bro. Also: The sound of a planet blowing up on an Apple resembled someone spilling a bowl of pistachio shells.

It sounds more like you want to say that the Apple II+ sucked. That’s fair. I don’t disagree with that. The sound was generated by a single click which if repeated fast enough became a buzz. I wrote a nice little routine to emulate pink noise, once, so it would sound like a car skidding. That was kind of cool.

I sense that you are too young to have first hand knowledge of these things, but if you do then your memories are just as faded as mine. I remember that we didn’t have flicker. And I was in the industry at the time developing games for the Apple II.