CODING
(C) Viper / Techno Laboratory
After seeing other computer paper,
I found there sections on
programmers. I think that our (VASHA!)
Newspaper is not worse (in my opinion, even
better than many) and it's time to fill this
gap.
Today there will be 4 treatments,
which are often used for
programming:
1) rapid procedure point
2) exchange of the two memory areas
3) the rapid division
4) the rapid multiplication
1) Over this procedure, a long time I broke
head and invented (as it turned out later)
bicycle. But then I thought
procedure even faster (69 cycles), but its
I will not give you, if anyone should, that he
come up with. :-)
This version takes 73 clock cycles for its
work must be 1024 bytes continuous
memory. Sub-create the tables call names CRT. Point coordinates
are given by in DE (XY). Tables are falling down, that is
if PTY = # FE00, then another 3-sector below
will be used. In the procedure itself
points (ZIP) second team
LD H, 'PTY
is nothing but an operation selection
High Byte (ALASM). Such a team
Available STORM, and as far as I
known ZXASM3. If your assembler does not
supports such things, ask
byte directly, although it is
uncomfortable.
; ZIP PLOT 1.4
; Author: Viper of TechnoLab
, 73 Tacts, 4 Tables take four sectors
; PTY - Down HiB, LEN = 192
; PTX - Down LoB, LEN = 192
; ADX - Div8 Lin, LEN = 256
; PTB - BitSet N, LEN = 256
PTY EQU # FF00
; PTX EQU # FE00
; ADX EQU # FD00> for help
; PTB EQU # FC00 /
ORG 40000
ENT
CALL CRT
LD DE, # 0909; coordinates of a point
CALL ZIP
RET
ZIP LD L, E
LD H, 'PTY
LD B, (HL)
DEC H
LD A, (HL)
DEC H
LD L, D
ADD A, (HL)
LD C, A
DEC H
LD A, (BC)
XOR (HL)
LD (BC), A
RET
CRT LD HL, PTY; creating tables
LD DE, # 4000; main screen
LD BC, # C020
CR1 LD (HL), D
DEC H
LD (HL), E
INC L
INC H
INC D
LD A, D
AND 7
JR NZ, $ +12
LD A, E
SUB # E0
LD E, A
JR NC, $ +6
LD A, D
SUB 8
LD D, A
DJNZ CR1
LD L, H; only for those addresses
DEC H; in general LD L, # FF
DEC H
CR3 DEC C
LD B, 8
CR2 LD (HL), C
DEC L
DJNZ CR2
INC C
DEC C
JR NZ, CR3
DEC H
INC A
CR4 LD (HL), A
RLCA
DEC L
DJNZ CR4
RET
