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CODING ...
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(C) Viper / TEchno Lab'99
Intro to 256 bytes?
In connection with the nomination 512 intro to CC999
some question arose, whether
write your intro in 256 bytes? The answer is simple -
not only possible, but this figure
easily blocked. An example is a Screen Saver for KrNews, which
you could watch for a few
numbers in a row. The reason for such constancy - a small
amount of memory required for his work. It takes only 153 bytes!
And if you remove the poll keypad (standard Screen Saver;),
then 145 bytes, brings it to the limit is 128 bytes. AND
this despite the fact that he actively uses
stack for its work. This Screen Saver - Full Screen (fullscreen)
Program is not required 128'oy memory.
Need only address table memory screen, located to the smooth
address, in this version # C000. Naturally, all realtime and
nothing is cut.
All this SS was written as a 96,
if not before, so do not blame me.
If someone does not know:
REPT 16
PUSH HL
ENDR
- Directive Zx Asm3.10, correspond
DUP 1916
PUSH HL; in Alasm'e
EDUP
.16 PUSH HL; - in Storm'e
-I mean PUSH repeat 16 times in a row
So:
BEG EQU 7; min-distance
ENX EQU 63; max-lines
GTAB EQU # C000; address table
ORG # 8000
FLIC LD DE, # 401F; construction
LD HL, GTAB; table
LD B, H
FLI INC DE
LD (HL), E
INC L
LD (HL), D
INC HL
DEC DE
INC D; standard Down
LD A, D
AND 7
JR NZ, FL1
LD A, E
SUB # E0
LD E, A
JR NC, FL1
LD A, D
SUB 8
LD D, A
FL1 DJNZ FLI
EI
LD DE, GTAB
EXX
LD E, 96; half of the screen
SFX LD B, BEG
CYCLE1 LD HL, # FFFF; terrible number
CALL CYC2
HALT
INC HL; inversion though:)
CALL CYC2
INC B
LD A, B
CP ENX
JR C, CYCLE1
CYCLE2 DEC HL; back to the Universe
CALL CYC2
HALT
INC HL
CALL CYC2
DEC B
LD A, B
CP BEG
JR NC, CYCLE2
JR SFX
CYC2 LD (OLDSP +1), SP
LD A, B
SRL A
CYC21 LD C, A
ADD A, E; added 96 for
; Middle of the screen
EXX
LD H, E; in the E -0
LD L, A
ADD HL, HL; multiplication by 2
ADD HL, DE; address, in which at
; Hoditsya display ad
, Res (well said)
LD SP, HL; in his stekpoynt
POP HL; display address
LD SP, HL; again stekpoynt
EXX
REPT 16
PUSH HL; long line
ENDR
SUB C; or LD A, E-no
SUB C; SUB C difference
EXX
LD H, E; symmetry is still
LD L, A
ADD HL, HL
ADD HL, DE
LD SP, HL
POP HL
LD SP, HL
EXX
REPT 16
PUSH HL
ENDR
LD A, C
ADD A, B
CP E; off the screen
JP C, CYC21; no climbs?
OLDSP LD SP, 0, and that the stack?
SUB A
IN A, (# FE); do not touch
CPL; keys!
AND # 1F
RET Z
POP HL
RET
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