21 Aug
2001
21 Aug
'01
10:42 p.m.
On Tue, 21 Aug 2001, Fred Cisin (XenoSoft) wrote:
Ok, here's my entry on the Apple ][ using no ROM routines:
0300: LDY #$00
0302: LDA $030C,Y
0305: BEQ $030B
0305: STA $0400,Y
0308: INY
0309: BNE $0302
030B: RTS ; or BRK
030C: C8 C5 CC CC CF A0 D7 CF D2 CC C4 00 ; "HELLO WORLD"
Damn, 26 bytes. Can't be any smaller, so Jay's Prime example still beats
it. Curse you, 6502!!! :)
Well, actually it could be one byte smaller:
0300: LDY #$00
0302: LDA $030B,Y
0305: BPL $0316
0305: STA $0400,Y
0308: INY
0309: BNE $0302
030B: C8 C5 CC CC CF A0 D7 CF D2 CC C4 00 ; "HELLO WORLD"
The BPL instruction will branch to location $0316 when it hits a value
less than #$80 (128), which happens to contain #$00, which is the null
terminator for the string which causes the loop to exit, but which also
happens to be the BRK (BReaK) instruction in 6502, which will cause a hard
interrupt and terminate the program.
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
Yes, but per
my earlier example.... are we shooting for less instructions in
the program or less intructions executed in total for the program? (ie, your
23 byte example is calling dos system services, so.... lots of additional
instructions there).
So far, nobody has set the rules for the game.
And if it is NOT to use OS API stuff, should we also outlaw using the OS
to start and end the program or even to load it?
How about routines in ROM? (PC BIOS INT 10h function 0Eh will display a
character)