mirror of
https://github.com/QB64-Phoenix-Edition/QB64pe.git
synced 2024-08-30 16:30:14 +00:00
153 lines
No EOL
4.3 KiB
Text
153 lines
No EOL
4.3 KiB
Text
Taito's Space Invaders
|
|
|
|
|
|
## The Invaders march ...
|
|
#### Bom bom bom bom ...
|
|
###### Left, right, fire!
|
|
## ## ## Faster, faster they march ...
|
|
######## Suddenly you're 11 again!
|
|
# # Dodge the bombs ...
|
|
# ## # They're turning green ...
|
|
# # # # Get them before they land!
|
|
|
|
|
|
A version of Taito's original Space Invaders(TM) for the PC
|
|
|
|
anarky, April 2005
|
|
|
|
http://www.anarky.tk/
|
|
anarkynet@hotmail.com
|
|
|
|
Disclaimer
|
|
|
|
This game is mailware. That is, it's free to use and distribute anywhere you
|
|
like, but only on condition that you keep the two files together and that you
|
|
don't charge any payment for it. Also, when you download it, email me on the
|
|
above address.
|
|
|
|
Also, I cannot be held responsible if this program does anything nasty to your
|
|
machine. It hasn't damaged anyone's PC that I'm aware of and there's no reason
|
|
why it should, really.
|
|
|
|
|
|
Playing
|
|
|
|
Start QuickBasic and load invader1.bas. Now press F5.
|
|
|
|
Left - Left CTRL
|
|
Right - Left ALT
|
|
Fire - Right SHIFT
|
|
Stop program - Esc
|
|
|
|
|
|
History
|
|
|
|
What's to be said? I remember as a kid playing the original on the big consoles.
|
|
So I thought, "Why not port it to the PC?" Heh, so I did.
|
|
|
|
|
|
Needs
|
|
|
|
Basically, don't worry - it'll almost certainly work on your PC.
|
|
|
|
Requires:
|
|
---------
|
|
|
|
DOS - tested with MS-DOS 7.1 and Windows 95. No known lower limit. I don't
|
|
know if it works with Windows 2000 or Windows ME.
|
|
|
|
VGA - tested with generic standard low-grade video card. It uses screen 13:
|
|
320x200x256, so it should work on yours no matter what it is.
|
|
|
|
Supports:
|
|
---------
|
|
|
|
Soundblaster - tested with AWE32. Make sure you've got your soundcard driver
|
|
set up for DOS (e.g. if you have a Soundblaster, a line starting 'SET BLASTER=' in your
|
|
c:\autoexec.bat file).
|
|
|
|
|
|
Technical
|
|
|
|
Uses ports:
|
|
-----------
|
|
|
|
&H3DA - for vertical retrace
|
|
|
|
&H388
|
|
&H389 - for Adlib sound
|
|
|
|
&H3C6
|
|
&H3C8
|
|
&H3C9 - for palette setting
|
|
|
|
Uses memory locations:
|
|
----------------------
|
|
|
|
&H417 - to read the keyboard
|
|
|
|
Machine speed requirements:
|
|
---------------------------
|
|
|
|
Should run at full speed on any x86 processor.
|
|
|
|
When interpreted, rather than compiled, the program does all its work
|
|
within 15% of the vertical retrace cycle on a 486DX/66. The compiled
|
|
version should keep up with the vertical retrace on an 8086.
|
|
|
|
If you press the '=' key, the game will display how much of the vertical
|
|
retrace time the game takes up each cycle. Exciting, eh?
|
|
|
|
Unknown requirements:
|
|
---------------------
|
|
|
|
Base memory - tested with 479K free base memory
|
|
Memory manager - tested with himem.sys and emm386.exe
|
|
|
|
|
|
Notes
|
|
|
|
1. The program does not attempt to detect a soundcard; it assumes a
|
|
Soundblaster is installed. Apparently it works ok on machines without a
|
|
soundcard, but I can't guarantee it'll work on yours.
|
|
|
|
2. The player's bullet fire and explosion sound effects are pretty
|
|
dismal. But so were the original sound effects.
|
|
|
|
3. The demo mode is none. I might add one in future.
|
|
|
|
4. The program simulates a monitor 256 pixels wide, as per the original (I
|
|
think). The background colour for this is set to a dark grey to attempt to
|
|
simulate a little bit of monitor wear and burn-in. I found the jet black of a
|
|
modern PC monitor was not quite authentic enough :-) If you cannot see the
|
|
grey background, try increasing your brightness and contrast controls.
|
|
|
|
5. There's no high-score table, because the original game didn't have one.
|
|
|
|
6. You can't re-assign the keys and it doesn't work with a joystick, sorry.
|
|
|
|
7. Quake it ain't. It's just a nostalgia trip.
|
|
|
|
|
|
Source Notes
|
|
|
|
The file invader1.bas is the source code for the game. It's for QBASIC and it
|
|
compiles with QuickBasic 4.5. It runs, interpreted, within QBASIC easily at
|
|
full speed on a 486/66, probably on lower-powered machines, too.
|
|
|
|
The code is reasonably structured. I tend to suffix variables with "s"
|
|
to mean "status", so the variable 'saucers' means 'saucer status'.
|
|
|
|
The SUBs and FUNCTIONs that start with "sb", e.g. "sbreset" are general-
|
|
purpose SoundBlaster routines that can be plugged into any program
|
|
without modification.
|
|
|
|
What else? Well, not much - it's a very simple program. Hope you find
|
|
it useful, though, if you're into this sort of thing!
|
|
|
|
|
|
History
|
|
|
|
v1 - Feb 2002
|
|
---------------
|
|
Version 1.0 ;) |