PROGRAMMERS
(C) JAGUAR
Today in the section 'Programmer' I have prepared for you
number of different routines, including
where you'll find:
- Quick procedure vycherchiva
of the circle.
- Accelerated DECRUNCHER to PA
kovschiku DATA_SQUEEZER v4.x.
- Correct handling of disk
errors in the formation
schenii to TR-DOS by # 3D13.
- As well as some more detail,
which are prepared specially
exponentially for beginners program
Misty, experienced the same ... MAKERy
can not even look at
these lines, but instead limit
dlagayu you experienced, collect
camping, and write us some
something his cunning subspace
gram, which we will publish
in the next edition of the newspaper.
Correct handling of disk
mistakes I have decided to publish in
this newspaper despite the fact
that this topic has already been considered
in the computer edition REHO 3
(ECHO), but since that was written about it there at all
is not a "proper treatment" - this is only correct failover in
the event of an error, try while reading the press on
BREAK and your program
immediately fly to some ...
(Eg 12345 or to the address
at 23,456.
*
Begin, as promised, with a procedure drawing on the screen
circle. At the entrance to procedure
you must specify three parameters:
akkamulyatore in the radius, a senior
byte of IX (HX) - coordinate of the center of the circle along
the axis Y, and younger (LX) - coordinate
Center for X. For example, to
draw a circle with a radius
80 in the center of the screen treatment
the procedure CIRCLE will look like:
LD A, 80
LD IX, # 6080
CALL CIRCLE
RET
CIRCLE LD E, 0
LD H, E
LD L, A
LD D, A
DEC D
SRL L
INC L
C1 PUSH DE
LD A, D
LD D, 0
BIT 7, H
JR NZ, C2
SLI E
RL D
SBC HL, DE
POP DE
JR C3
C2 SUB E
DEC A
ADD A, A
RL D
LD E, A
ADD HL, DE
POP DE
DEC D
C3 PUSH HL
LD B, D
LD C, E
PUSH DE
CALL CIR1
LD A, B
LD B, C
LD C, A
CALL CIR1
POP DE
POP HL
INC E
LD A, E
CP D
JR C, C1
RET
CIR1 LD A, B
ADD A, XH
JR C, C4
LD D, A
LD A, C
ADD A, XL
JR C, C4
LD E, A
CALL CIR2
C4 LD A, XH
SUB B
JR C, C5
LD D, A
LD A, C
ADD A, XL
JR C, C5
LD E, A
CALL CIR2
C5 LD A, XH
SUB B
JR C, C6
LD D, A
LD A, XL
SUB C
JR C, C6
LD E, A
CALL CIR2
C6 LD A, B
ADD A, XH
RET C
LD D, A
LD A, XL
SUB C
RET C
LD E, A
CALL CIR2
RET
CIR2 LD A, D
CP 192
RET NC
LD A, E
CPL
AND 7
ADD A, A
ADD A, A
ADD A, A
ADD A, 199
LD (BITNUM +1), A
SRL E
SRL E
SRL E
LD A, D
AND 56
RLCA
RLCA
OR E
LD L, A
LD A, D
AND 7
LD E, A
LD A, D
AND 192
RRA
SCF
RRA
RRA
OR E
LD H, A
XOR A
BITNUM SET 0, A
OR (HL)
LD (HL), A
RET
*
