mirror of
https://github.com/deater/dos33fsprogs.git
synced 2024-07-01 18:29:27 +00:00
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
|
|
drawing)?
|
|
|
|
A. No, this is just a quick hack using all sprites.
|
|
I'm not doing something amazing like writing a 6502 optimized
|
|
vector drawing library.
|
|
|
|
---
|
|
|
|
|
|
Q. Why aren't the keyboard controls the same as the original game?
|
|
|
|
A. The Apple II has simplistic keyboard support.
|
|
In general it's not possible to read more than one key at a time.
|
|
Additionally, on older models there's no auto-repeat unless you
|
|
hold down the REPT key, which makes running difficult.
|
|
The original game really depends on being able to detect having
|
|
multiple keys down at once.
|
|
|
|
---
|
|
|
|
Q. Does this have joystick support?
|
|
|
|
A. It should not be hard to add, and in fact would give better controls
|
|
than the keyboard. I don't currently have a joystick though so
|
|
it's hard to test properly.
|
|
|
|
----
|
|
|
|
Q. Is there anything impressive going on here, like with your other demos?
|
|
|
|
A. No, it's pretty much straight up "sprite" drawing.
|
|
One unusual thing is I am using grey2 (color 10) as the transparent
|
|
color rather than black, as there is black in the sprites.
|
|
|
|
It's actually refreshing not having to cycle count.
|
|
|
|
---
|
|
|
|
|
|
Q. How are you making the graphics?
|
|
|
|
A. Using the original for reference (currently a Windows/EGA version
|
|
for some reason?) Size down to 80x40. Manually map colors to
|
|
Apple II Lo-res palette. Then manually adjust to 40x40.
|
|
Finally fine tune in a bit while using original for reference.
|
|
|
|
|
|
---
|
|
|
|
Q. Why lores graphics? It's so *horribly* blocky.
|
|
|
|
A. Yes, but I like it anyway. So many colors!
|
|
I spent a lot of time as an ANSI artist so I am used to blocky
|
|
16-color graphics, and to be honest with you my art skills sort
|
|
of peak at that resolution.
|
|
|
|
Also Apple II graphics programming is painful and LORES is the
|
|
easiest of them all.
|
|
|
|
Partly nostalgia too, but my family only had a monochrome monitor
|
|
so I never got to experience full-color lores back in the day.
|
|
Unfortunately this game doesn't really play well in monochrome.
|
|
|
|
---
|
|
|
|
Q. Are you going to make a version using Hi-res or Double Hi-res graphics?
|
|
|
|
A. No, there's an official version for the Apple IIgs if you want something
|
|
like that. Apple II hires graphics with sprites are a huge pain
|
|
to program, would probably be slower, and would take up a lot more
|
|
RAM.
|
|
|
|
---
|
|
|
|
Q. How about double-lores graphics (80x48)? It would give you almost
|
|
square pixels?
|
|
|
|
A. While not as bad as Hires, double-lores is also a pain. It only
|
|
works on the IIe with 128k or newer. Also you now have to copy
|
|
things to aux memory, and your sprites have to worry about the
|
|
colors being shifted (I think) on the AUX page. It will take
|
|
twice the ram and probably run 1/2 the speed.
|
|
|
|
Also the current code uses page-flipping to avoid flicker/tearing,
|
|
but doing page-flipping in double-lores is really tricky.
|
|
|
|
---
|
|
|
|
Q. Why are you targeting such an old machine, an original Apple II or II+?
|
|
|
|
A. Well, I own one. Also there's something about programming on a machine
|
|
from 1977, whose graphics hardware is a glorified shift register,
|
|
and is implemented entirely out of 7400 series logic and 555 timers.
|
|
|
|
---
|
|
|
|
Q. In the intro, why not have lowercase letters?
|
|
|
|
A. The Apple II/II+ only supported uppercase letters by default.
|
|
Also no "|" character, which explains why some of the ASCII art
|
|
looks a bit odd.
|
|
|
|
I suppose I could auto-uppercase on older machines on the fly like
|
|
my Still Alive demo does. The memory budget is a bit tight though.
|
|
|
|
---
|
|
|
|
Q. Could you really use this on an original Apple II from 1977?
|
|
|
|
A. Yes, in theory. You would have needed a 48k model which would
|
|
have been expensive at the time ($2638). Also the disk image
|
|
will fail to auto-boot and HELLO won't run as it's in Applesoft
|
|
BASIC (not the Integer BASIC that came with the original II).
|
|
You'll have to manually type C600G and then POKE 0,1 or 2
|
|
to address 5 (to select intro, level1 or level2) and then
|
|
BRUN LOADER
|
|
|
|
|