CRC for betting

Hi, All! The subject algorithm is better, pls. Bye, Yuri.

23-08-98 15:41:00 Yuri Burawtsow ==> All Hi Yuri! YB> The subject algorithm is better, pls. Here I picked something up in my archive: figure it out yourself... These are just pieces of several files where this is mentioned... == Cut == Structure of the 17-byte header added to TR-DOS files using HoBeta.exe: 00-07 - file name 08 - file type 09-0A - Start 0B-0C - Length 0D-0E - Length in 256-byte records (byte 0E - size in sectors) 0F-10 - Checksum Thus, the first 14 bytes are copied from the TR-DOS directory. Checksum calculation: S=S+257*Di+i, where S initial=0 Di - byte value i - byte sequence number (if I’m not mistaken, starting from 0, not 1) C src: */ #include #include #include #include #include #include #include void main(int argc, char *argv[]) { int inh, outh, i, inlen, outlen, CheckSum, w, t; char *file; unsigned char buf[10]; union { struct { unsigned char tr_filename[8]; unsigned char tr_filetype; unsigned int tr_address; unsigned int tr_length; unsigned int tr_tr; unsigned int tr_crc; } tr_head; unsigned char head[17]; } header; file = argv[1]; w = *buf; inh = open(file, O_BINARY|O_RDWR); inlen = filelength(inh);read(inh, header.head, 17); CheckSum=0; for (i=0; i<=14; CheckSum = CheckSum + (header.head[i] * 257) + i, i++); if (header.tr_head.tr_crc != CheckSum) { printf("Not hobeta!!"); exit(1); } printf("Found file "); for (i=0; i<=7; i++) printf("%c", header.head[i]); printf(" <%c> %d byte", header.head[8], header.tr_head.tr_length); /* unsigned int CheckSum; CheckSum=0; for (i=0; i<=14; CheckSum = CheckSum + (header.head[i] * 257) + i, i++); header.tr_head.tr_crc = CheckSum; /*I found such a funny way of counting in one of my programs header checksum: checksum=0; for (i=0; i<=14; checksum+=(unsigned char)*(bufptr+i), i++); checksum*=257; checksum+=105; bufptr is obviously a pointer to the beginning of the header. === Cut === Well that's all *MAS* with a sledgehammer

Greetings to you, oh dearest Aleksandr! On a lunar day 08/24/98 at 22:30:00 someone Aleksandr Majorov in finally wrote 2 Yuri Burawtsow on the topic 'CRC for hobeting'. 23-08-98 15:41:00 Yuri Burawtsow ==>> All [skipatizhi] AM> figure it out yourself... Thank you, I figured it out. I thought I needed a control read the sum of the entire file, but it turns out that only three descriptor... In short, I wrote here a small MS-DOS-like echo processor. Who is it for? For writers without HAYES, but with Specky, to which VICOMM (or XTR) is connected. That is, for those like me. Boris Sokol has also shown interest in this development... How to set DN, NC, VC or anything similar? 1. Write the reaction to the extension in the extension file unread echo (for example, '*.$e'). Run the tosser.exe file; 2. Write a reaction to the extension '*.mai' - extension personal unanswered letter. Run the file echoproc.exe; 3. Write a reaction to the extension '*.re' - extension of the answered letter. Run the glue.exe file; 4. Customize the files to suit your characteristics and email format: general.cfg mailsys.cfg. What should you do before using the processor? 1. Copy the latest echoes and letters from the diskette. 2. Name the freshly copied files something special. Ehi, for example, they are already called '*.$e'. How to use the processor?1. Being in some shell, highlight the echoes one by one another and press ENTER on each (processing the marked ones for now not implemented). A launched tosser does: - search for letters addressed to the operator and select them from the file under names 'xxxx.mai