CRC-16 bit
ZXNet echo conference «code.zx»
Hello Orionsoft
Ori> who can suggest a procedure that counts the subject, but is not limited to 256
Ori> bytes as in the well-known source ...
For X-modem;
┌─-; code ───
crc=0;
for (i=0; i= sizeof(buff)) {
debug0("buffer overflow!
");
send_break("buffer overflow!");
return 0;
}
while (1) {
CHECK_TIMEOUT;
if (kbhit()) {
buff[ptr+i] = c = getch();
crc^=((unsigned)c<<8)&0xff00;
b=8;
do {
if (crc&0x8000) crc<<=1, crc^=0x1021;
else crc<<=1;
} while (--b!=0);
break;
}
}
}
└── code ───
In general, at one time in CODE.ZX this issue was considered, given
all sorts of procedures, and in my opinion it was even explained that that sign is simply built
through a tableless algorithm and can easily be generated dynamically when
Need speed and compactness. And even in my zxlib there is such an algorithm:I just couldn't insert it. The message is long, do you understand? And
It’s also not much fun to suffer in a window the size of 1/16 of a monitor. Therefore not
I will write nothing more meaningful here. Just rave and get confused.
Ask at fido7.zx.spectrum.
Hello, All
who can suggest a procedure that counts the subject, but is not limited to 256 bytes like
in the well-known source...
Hello, Orionsoft
о нашел и проверил , она правильно расчитывает в формате cciit
CRC16;
;Borrowed; from http://zilog.sh.cvut.cz/~base/misc/z80bits.html
; and moddified to be a loop
;The arrow comments show what lines I added or commented out from the original.
;Inputs; de->data; bc=number of bytes
;Outputs; hl=CRC16;
push bc ;<---<<<
push de ;<---<<<
push af ;<---<<<
ld hl,$FFFF
push bc ;<---<<<
CRC16_Read;
ld; a,(de)
inc de
xor h
ld h,a
ld b,8
CRC16_CrcByte;
add; hl,hl
jr nc,CRC16_Next
ld a,h
xor $10
ld h,a
ld a,l
xor $21
ld l,a
CRC16_Next;
djnz; CRC16_CrcByte
; dec c ;>>>--->
pop bc ;<---<<<
dec bc ;<---<<<
push bc ;<---<<<
ld a,b ;<---<<<
or c ;<---<<<
jr nz,CRC16_Read
pop bc ;<---<<<
pop af ;<---<<<
pop de ;<---<<<
pop bc ;<---<<<
ret
Hello Orionsoft
Ori> who can suggest a procedure that counts the subject, but is not limited to 256
Ori> bytes as in the well-known source ...
source hrust2.x
Hello fk0
Here's from fk0.
File: zxlib_crc_fk0.zip http://zx.pk.ru/attachment.php?attachmentid=4300