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120 lines
3.9 KiB
Plaintext
120 lines
3.9 KiB
Plaintext
Q. Are you implementing the game just like the original (i.e. vector
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drawing)?
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A. No, this is just a quick hack using all sprites.
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I'm not doing something amazing like writing a 6502 optimized
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vector drawing library.
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---
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Q. Why aren't the keyboard controls the same as the original game?
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A. The Apple II has simplistic keyboard support.
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In general it's not possible to read more than one key at a time.
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Additionally, on older models there's no auto-repeat unless you
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hold down the REPT key, which makes running difficult.
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The original game really depends on being able to detect having
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multiple keys down at once.
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---
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Q. Does this have joystick support?
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A. It should not be hard to add, and in fact would give better controls
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than the keyboard. I don't currently have a joystick though so
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it's hard to test properly.
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----
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Q. Is there anything impressive going on here, like with your other demos?
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A. No, it's pretty much straight up "sprite" drawing.
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One unusual thing is I am using grey2 (color 10) as the transparent
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color rather than black, as there is black in the sprites.
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It's actually refreshing not having to cycle count.
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---
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Q. How are you making the graphics?
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A. Using the original for reference (currently a Windows/EGA version
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for some reason?) Size down to 80x40. Manually map colors to
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Apple II Lo-res palette. Then manually adjust to 40x40.
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Finally fine tune in a bit while using original for reference.
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---
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Q. Why lores graphics? It's so *horribly* blocky.
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A. Yes, but I like it anyway. So many colors!
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I spent a lot of time as an ANSI artist so I am used to blocky
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16-color graphics, and to be honest with you my art skills sort
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of peak at that resolution.
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Also Apple II graphics programming is painful and LORES is the
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easiest of them all.
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Partly nostalgia too, but my family only had a monochrome monitor
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so I never got to experience full-color lores back in the day.
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Unfortunately this game doesn't really play well in monochrome.
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---
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Q. Are you going to make a version using Hi-res or Double Hi-res graphics?
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A. No, there's an official version for the Apple IIgs if you want something
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like that. Apple II hires graphics with sprites are a huge pain
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to program, would probably be slower, and would take up a lot more
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RAM.
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---
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Q. How about double-lores graphics (80x48)? It would give you almost
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square pixels?
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A. While not as bad as Hires, double-lores is also a pain. It only
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works on the IIe with 128k or newer. Also you now have to copy
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things to aux memory, and your sprites have to worry about the
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colors being shifted (I think) on the AUX page. It will take
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twice the ram and probably run 1/2 the speed.
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Also the current code uses page-flipping to avoid flicker/tearing,
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but doing page-flipping in double-lores is really tricky.
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---
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Q. Why are you targeting such an old machine, an original Apple II or II+?
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A. Well, I own one. Also there's something about programming on a machine
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from 1977, whose graphics hardware is a glorified shift register,
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and is implemented entirely out of 7400 series logic and 555 timers.
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Q. In the intro, why not have lowercase letters?
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A. The Apple II/II+ only supported uppercase letters by default.
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Also no "|" character, which explains why some of the ASCII art
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looks a bit odd.
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I suppose I could auto-uppercase on older machines on the fly like
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my Still Alive demo does. The memory budget is a bit tight though.
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---
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Q. Could you really use this on an original Apple II from 1977?
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A. Yes, in theory. You would have needed a 48k model which would
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have been expensive at the time ($2638). Also the disk image
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will fail to auto-boot and HELLO won't run as it's in Applesoft
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BASIC (not the Integer BASIC that came with the original II).
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You'll have to manually type C600G and then POKE 0,1 or 2
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to address 5 (to select intro, level1 or level2) and then
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BRUN LOADER
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