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ZX Review #7-8-9-10
08 ноября 1997 |
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Retro - 40 best treatments: Removal of REM-strings.
7.3. Removal of REM-strings
Length: 132
Number of variables: 0
Checksum: 13809
Purpose: This program removes all comments from
BEYSIKprogrammy.
Subroutine call:
RANDOMIZE USR address
Error checking: If no-BASIC program, the procedure returns to
BASIC without any action.
Comment: The procedure ROM
which is used to delete characters, is not running
very quickly and therefore routine "removal REM-lines" running
slow.
LISTING machine code
Assembly label number to VVODA147.
LD HL, (23635) 42 83 92
JR CHECK 24 31
NEXT_L PUSH HL 229
INC HL 35
INC HL 35
LD C, (HL) 78
INC HL 35
LD B, (HL) 70
NXT_CH INC HL 35
LD A, (HL) 126
CP 33254 1933
JR C, NXT_CH 56250
CP 234 254 234
JR NZ, SEARCH 32 26
INC BC 3
INC BC 3
INC BC 3
INC BC 3
POP HL 225
DEL_L PUSH BC 197
CALL 4120 205 24 16
POP BC 193
DEC BC 11
LD A, B 120
OR C 177
JR NZ, DEL_L 32246
CHECK LD DE, (23,627) two hundred thirty-seven 91 75 92
AND A 167
SBC HL, DE 237 82
RET NC 208
ADD HL, DE 25
JR NEXT_L 24214
SEARCH INC HL 35
LD A, (HL) 126
CP 13254 1913
JR NZ, N_ENT 32 8
ENT_FD POP HL 225
ADD HL, BC 9
INC HL 35
INC HL 35
INC HL 35
INC HL 35
JR CHECK 24231
N_ENT CP 14254 1914
JR NZ, N_NUMB 32 7
INC HL 35
INC HL 35
INC HL 35
INC HL 35
INC HL 35
JR SEARCH 24,231
N_NUMB CP 33254 1933
JR C, SEARCH 56,227
CP 34254 1934
JR NZ, N_QUOT 32 8
FD_QT INC HL 35
LD A, (HL) 126
CP 34254 1934
JR NZ, FD_QT 32250
JR SEARCH 24,215
N_QUOT CP 58254 1958
JR NZ, SEARCH 32,211
LD D, H 84
LD E, L 93
FD_ENT INC HL 35
LD A, (HL) 126
CP 13254 1913
JR Z, ENT_FD 40209
CP 33254 1933
JR C, FD_ENT 56246
CP 234 254 234
JR NZ, N_QUOT 32236
LD H, D 98
LD L, E 107
DEL_CH PUSH BC 197
CALL 4120 205 24 16
POP BC 193
DEC BC 11
LD A, (HL) 126
CP 13254 1913
JR NZ, DEL_CH 32245
POP HL 225
INC HL 35
INC HL 35
LD (HL), C 113
INC HL 35
LD (HL), B 112
DEC HL 1943
DEC HL 1943
DEC HL 1943
JR CHECK 24160
Error control: if the number
bytes to copy is 0
or the first line is already there,
the program returns to BASIC.
The program does not check if there is enough memory for the
new line. The program requires 10 bytes per byte of data plus
five bytes Line numbers, pointers
length, etc. In addition, the used subroutine ROM also uses a
large working area - take this into account. If the available
memory is not enough, signs line will be installed correctly
and BASIC listing is not reliable.
Comment: The time involved in work of this program is
proportional to the amount of memory for copying.
LISTING machine code
Assembly label number to VVODA147.
LD DE, (23296) 237 91 0 91
LD BC, (23298) 237 75 February 1991
LD A, B 120
OR C 177
RET Z 200
LD HL, (23635) 42 83 92
LD A, (HL) 126
CP 0254 0
JR NZ, CONT 32 6
INC HL 35
LD A, (HL) 126
CP 1 254 1
RET Z 200
DEC HL 1943
CONT PUSH HL 229
PUSH BC 197
PUSH DE 213
SUB A 151
CALL 3976 205 136 1915
EX DE, HL 235
LD A, 1 January 1962
CALL 3976 205 136 1915
EX DE, HL 235
CALL 3976 205 136 1915
EX DE, HL 235
CALL 3976 205 136 1915
EX DE, HL 235
LD A, 228 62 228
CALL 3976 205 136 1915
EX DE, HL 235
NEXT_B POP DE 209
LD A, (DE) 26
PUSH DE 213
LD C, 47 14 47
HUNDR INC C 12
LD B, 100 6100
SUB B 144
JR NC, HUNDR 48250
ADD A, B 128
LD B, A 71
LD A, C 121
PUSH BC 197
CALL 3976 205 136 1915
EX DE, HL 235
POP BC 193
LD A, B 120
LD C, 47 14 47
TENS INC C 12
LD B, 10 June 1910
SUB B 144
JR NC, TENS 48250
ADD A, B 128
LD B, A 71
LD A, C 121
PUSH BC 197
CALL 3976 205 136 1915
POP BC 193
EX DE, HL 235
LD A, B 120
ADD A, 48 198 1948
CALL 3976 205 136 1915
EX DE, HL 235
LD A, 14 62 14
LD B, 6 6 6
N_ZERO PUSH BC 197
CALL 3976 205 136 1915
POP BC 193
EX DE, HL 235
SUB A 151
DJNZ N_ZERO 16247
POP DE 209
PUSH HL 229
DEC HL 1943
DEC HL 1943
DEC HL 1943
LD A, (DE) 26
LD (HL), A 119
POP HL 225
INC DE 1919
POP BC 193
DEC BC 11
LD A, B 120
OR C 177
JR Z, ENTER 40 10
PUSH BC 197
PUSH DE 213
LD A, 44 62 44
CALL 3976 205 136 1915
EX DE, HL 235
JR NEXT_B 24173
ENTER LD A, 13 62 13
CALL 3976 205 136 1915
POP HL 225
LD BC, 0 1 0 0
INC HL 35
INC HL 35
LD D, H 84
LD E, L 93
INC HL 35
POINT INC HL 35
INC BC 3
LD A, (HL) 126
CP 14254 1914
JR NZ, END? 32 12
INC BC 3
INC BC 3
INC BC 3
INC BC 3
INC BC 3
INC HL 35
INC HL 35
INC HL 35
INC HL 35
INC HL 35
JR POINT 24237
END? CP 13254 1913
JR NZ POINT 32233
LD A, C 121
LD (DE), A 18
INC DE 1919
LD A, B 120
LD (DE), A 18
RET 201
2
How it works:
In a couple of registers DE loads the address of bytes to copy
and a pair of registers loaded BC number of bytes to copy.
If BC contains 0, the program
returns to BASIC.
In a couple of registers, the address is loaded HL-BASIC
program. As the battery is loaded a byte from address specified
in HL. This byte line number. If
it is not 0, the first line of not
exists and the program jumps to CONT. If the high byte
contain 0, the accumulator is loaded least significant byte. If
this value set to 1, the first line already exists and
the program returns to BASIC.
Address high byte numbers
string is stored on the stack.
Preserved the number of bytes to copy, then the address data. In
battery is loaded 0 (high byte of a new line number).
Caused by routine ROM, located at 3976, inserts the character
with the battery, at the address set in the HL.
In HL reduced the value stored at this before this
operation. In a battery is loaded, and this value is inserted 3
times. The first unit - is the low byte line number
the following two - the length of the pointer
line. In the battery and then load the character code DATA and
is value is entered in a row.
Address of the next byte of data
recovered from the stack and
loaded into the DE. This itself bytes
loaded into the accumulator and the contents stored in the DE
again stack. The C-register is loaded
value of 1 less than the code
symbol 0. C-register is increased, and the B-register value is
loaded 100. B-register is subtracted from the battery and, if
the result is negative, the routine returns to HUNDR.
B-register is added to the battery (so the battery has a
positive value). This value is then
loaded into the B-register. As the battery is loaded content
C-register, and BC remains at
stack. Calling routines ROM
(3976), is inserted into the symbol that is stored in the
battery, the address contained in the HL. BC register pair is
recovered from the stack, and a battery load value B-register.
The above-mentioned method is then repeated for the B = 10.
Battery is then increased by 48 and the resulting character is
inserted into the string.
The above-described subroutine interpolate decimal
representation occurs bytes Data in the expression of DATA. Now
should be inserted into a binary
representation. This value is marked with the code NUMBER
(CHR 14), which is introduced first, followed by five zeros.
The value of bytes copied is placed in a cell to replace third
zero. DE increases pointing to the next byte of data. The
number of bytes to copy is removed from the stack in the BC and
this value decreases. If the result is 0, a transition is made
to the ENTER, otherwise the contents register pairs BC and DE
again pushed onto the stack, the expression
DATA includes a comma, and the program returns to NEXT_B.
This procedure code ENTER
(End of line) is added to
marking the end of the expression of DATA.
In HL load address of the beginning
line, and BC is set to
0. HL increased, indicating
pointer to low byte strings, and this new address is copied
into the DE. HL increased, pointing to the byte pointer line.
HL and BC then incremented, and the battery is loaded symbol,
located on address in HL.
If the battery contains the code
14 - the number is found, the HL and BC
increases by 5, jumping over the number and pointing to the
character following behind him. Subroutine then proceeds to
POINT.
If the battery does not contain
values of 14 and 13, the transition to a POINT.
Completion of the formation line is executed by putting the
contents of BC in the cell pointer string length. To the
desired address points DE. At the end of of the procedure
executes, returned to BASIC.
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