Additional information.
There are some hidden instruments in SmileBASIC.
For example, @256 is saw tooth wave, one of the most famous 8-BIT sound.
And it is better to use @266 as noise source rather than @151 to reproduce like wind blowing sound.
Almost all legacy game platform had simple and cheap sound generator IC. If you reproduce such 8-BIT sound, you should use @144-@150 or @151 for music instrument, and use less than three music parts.
It is very difficult for me to tell you how to compose a music, just I can tell you is how to choose instrument for 8-BIT sound.
Choose instrument @144-@150(square waves with various duty ratio) or @151(noise).
SPCOL N,TRUE should be followed by SPSCALE.
The second argument of SPCOL allows collision detection area to follow sprite size, but if SPCOL N,TRUE is done after SPSCALE, size of collision detection area will be kept the state before SPSCALE is done.
AND is the most often-used operator to detect multiple button pressing.
If you press L without pressing R,
((K AND #L)!=0)==TRUE, ((K AND #R)!=0)==FALSE
If you press R without pressing L,
((K AND #L)!=0)==FALSE, ((K AND #R)!=0)==TRUE
If you press both L and R at the same time,
((K AND #L)!=0)==TRUE, ((K AND #R)!=0)==TRUE
The method is so simple. Replace line 61 with follows.
X1=X1+((K AND #LEFT)!=0)*2
X2=X2+((K AND #B)!=0)*2
X3=X3+((K AND #L)!=0)*2
X4=X4+((K AND #R)!=0)*2
If you replace "*2" by greater value, the car will move faster.
@BeefJerkey:
I'm sorry I don't understand what do you want to know exactly, but I guess you want to avoid moving a sprite continuously.
If so, the method is very easy. Could you refer to the attached photo? If you write "(0)" instead of "(2)" in line 8, a sprite will move continuously as long as you press A button.
@BeefJerkey:
I wrote that if an aircraft land on carrier deck with keeping supersonic speed, all people on deck will be blown off by sonic boom.
In my opinion, Japanese is one of the most difficult language to translate automatically, because one Japanese Kanji character often has plural meanings. For example, "生" has at least three meanings, "born", "live" and "raw".