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****************** Harrier Attack *******************
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************************ (c) 1993 Voodoo Software *************************
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------------------- Just a few notes about the game... --------------------
1. System Compatibility
1.1 It's all system, but...
The entire game is written in a very system-friendly way. However, for
speed and synchronization reasons, the scrolling routines bypass
graphics.library and use the blitter directly. If the 'graphic lib'
scrolling option is selected, the game will use a system function to
_scroll_, but it will still utilize blitter to clear the rightmost 2-7
pixel columns.
1.2 ...and also...
The second and last method I use that may not be the best one is the way I
add my user copper list. I simply find the ViewPort of my newly opened
screen and write the pointer to my UCopList structure to the UCopIns field.
I don't think this can cause any problems as intuition doesn't install its
own UCopLists (why should it?) and I'm very likely to be the first who
finds out about the existence of my screen.
1.3 Public disgrace of graphics.library
While writimg the game, I have encountered an interesting problem:
Originally, I intended to use WaitBOVP() to synchronize my gfx output and
thus avoid flickering etc., but then I discovered that the function busy
waits for the video beam to reach the desired position, which is
unacceptable. I decided to add an user copper list and have it generate a
copper interrupt when the beam is past the dangerous area. The problem was
that I didn't figure out any really reliable way to decide whether a copper
interrupt was caused by my coplist or by something else. The game
circumvents this problem by accepting only those interrupts that occur
below my 'playfield' and are not preceded by another accepted interrupt in
this frame. If no copint has been accepted for a whole frame, it is
simulated by the next vertical blank interrupt. If you know of a more
graceful solution, please let me know.
1.4 Testing
Harrier Attack was tested and found operating on the following machines...
Amiga CPU CHIPSET RAM (C/F) OS
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500 68000 original 0.5/0.5MB 1.3
500 68000 original 1.0/2.0MB 2.1
1200 68EC020 AA 2.0/0.0MB 3.0
I think it is reasonable to expect Harrier Attack to work on ALL 1.3+
Amigas.
2. Game Options
2.1 Controls
The game can be controlled by keyboard only. There are two predefined sets
of keys: Traditional = '5','8','7','6','0','9','space' and
'O','P','Q','A','M','N','G', in left-right-up-down-fire-bomb-pause order.
There's also a user-definable set which is expected to be used in most
cases. Please note that as far as I know, the A1200 cannot read two keys
in one row pressed at the same time, which renders both predefined sets
useless. As any other option, the defined keys are saved in
'harrier.prefs'.
2.2 AutoPause
When this option is selected, the game will be automatically paused
whenever its window becomes inactive.
2.3 AutoSave
When this option is selected, the top ten scores are saved following every
new hero being entered.
2.4 Priority
If the scrolling isn't smooth try setting a higher priority. On the other
hand, if you think that your computer has better things to do (tasks to
attend to) than Harrier Attack, set its priority low to favor other tasks.
2.5 Scrolling
I included this option because I thought that setting it to 'Graphics lib'
might save some CPU time on high-end Amigas. I don't know if this is the
case or not, but I suggest keeping it set to 'Direct Blit'. See also 1.1
3 Saving Scores and Preferences
The Disk menu lets you save your preferences (all settings discussed in
chapter (hahaha) 2 plus the last level played) to S: or any other
directory whose name you pass to the game as a command line parameter.
4 Credits, Please...
I'd like to thank to...
Clive Sinclair for ZX Spectrum
M.A. Richardson for the original Harrier Attack!
Fractalus for testing
If you like my game, please send me a postcard, e-mail me a picture (not by
fidonet!!!) or something like that.
5 Addresses
You can contact me for whatever reason at:
SNAILMAIL: Voodoo Software
Sikma 17
130 00 Praha 3
Czech republic
INTERNET: partl@km1.fjfi.cvut.cz
FIDONET: 2:420/24.902
(I can't process mail right now though, 'cause
pmanager doesn't seem to like my A1200 and I don't
know how to make them become friends.)
----------------------------- Enjoy the Game! -----------------------------
A T T A C K !!!!
