/*************************************************************************** mmcpm - List and extract files from CP/M 2.2 disk image files begin : 10/11/2006 copyright : (c) 2006 by Michael Minn email : See http://www.michaelminn.com Code in this file is intended to be platform independent. Please do not use references to functions other than standard POSIX. This program is free software; you can redistribute it and/or modify it under the terms of version 2 of the GNU General Public License as published by the Free Software Foundation (see COPYING or www.gnu.org). ***************************************************************************/ #include #include #include #include #include #include #include /* See README.html for explanation of these configuration constants */ #define SECTOR_SIZE 512 #define SECTORS_PER_TRACK 10 #define BYTES_PER_SIDE 179200 #define ALLOCATION_BLOCK_SIZE 2048 #define SECTOR_SKEW 2 #define SIDE_INTERLEAVE 1 #define SYSTEM_TRACKS 2 #define DIRECTORY_SIZE 2048 #define ONES_COMPLIMENT 1 #define BUFFER_SIZE 2000000 #define EXAMINE_FILE "mmcpm.img" int print_syntax() { fprintf(stderr, "SYNTAX: mmcpm [copy | examine] \n"); exit(-1); } int main(int argc, char **argv) { unsigned char data[BUFFER_SIZE]; char *filename = NULL; int copy_files = 0; int examine = 0; /* command line arguments */ if (argc == 2) filename = argv[1]; else if ((argc == 3) && (argv[1][0] == 'c')) { copy_files = 1; filename = argv[2]; } else if ((argc == 3) && (argv[1][0] == 'e')) { examine = 1; filename = argv[2]; } else print_syntax(); /* Read the image file */ int descriptor = 0; if ((descriptor = open(filename, O_RDONLY)) < 0) return fprintf(stderr, "%s: %s\n", strerror(errno), filename); int length = 0; if ((length = read(descriptor, data, BUFFER_SIZE)) < 0) return fprintf(stderr, "%s: %s\n", strerror(errno), filename); close(descriptor); /* If the image exceeds the maximum for a single-sided disk, it must be double-sided */ int sides = 1; if (length > BYTES_PER_SIDE) sides = 2; /* The SuperBrain stores data with the bits inverted */ if (ONES_COMPLIMENT) { int x; for (x = 0; x < length; ++x) data[x] = ~data[x]; } /* Some images are stored with sides interleaved (cyl 1 side 1, cyl 1-side 2, cyl 2 side 1, cyl 2 side 2...) */ /* even though data is used as if all of side 1 is together and all of side 2 follows */ /* This code de-interleaves data, if needed */ if ((sides > 1) && SIDE_INTERLEAVE) { int cylinder = 0; int track_size = SECTOR_SIZE * SECTORS_PER_TRACK; unsigned char buffer[BUFFER_SIZE]; memcpy(buffer, data, length); for (cylinder = 0; cylinder < length; cylinder += (track_size * 2)) { // fprintf(stderr, "0x%x > 0x%x 0x%x\n", cylinder, (cylinder / 2), (cylinder / 2) + (length / 2)); memcpy(data + (cylinder / 2), buffer + cylinder, track_size); memcpy(data + (length / 2) + (cylinder / 2), buffer + cylinder + track_size, track_size); } } /* Some old, slow CPUs and buses couldn't handle data at the rate it came off the disk. */ /* So sectors were skewed to provide time for processing a sector before the next one came around. */ /* A skew of 2 with 10 sectors per track means data stored in sectors in order 0 2 4 6 8 1 3 5 7 9 */ /* This code deskews the data, if needed */ if (SECTOR_SKEW > 0) { int track = 0; int sector = 0; int track_size = SECTOR_SIZE * SECTORS_PER_TRACK; unsigned char buffer[BUFFER_SIZE]; memcpy(buffer, data, length); for (track = 0; track < length; track += track_size) for (sector = 0; sector < SECTORS_PER_TRACK; ++sector) { int source = sector * SECTOR_SKEW; while (source >= SECTORS_PER_TRACK) source = source + 1 - SECTORS_PER_TRACK; memcpy(data + track + (sector * SECTOR_SIZE), buffer + track + (source * SECTOR_SIZE), SECTOR_SIZE); } } /* Performs a hex dump of the modified image and, also, saves it to a file */ if (examine) { int x = 0; for (x = 0; x < length; x += 16) { int y = 0; printf("%06x ", x); for (y = 0; y < 16; ++y) printf("%02x ", data[x + y]); for (y = 0; y < 16; ++y) if ((data[x + y] >= ' ') && (data[x + y] <= 127)) printf("%c", data[x + y]); else printf("."); printf("\n"); } if ((descriptor = open(EXAMINE_FILE, O_WRONLY | O_CREAT | O_TRUNC, 0644)) > 0) { write(descriptor, data, length); close(descriptor); printf("Modified image saved to %s\n", EXAMINE_FILE); } } /* Traverse the directory entries */ int directory_start = SYSTEM_TRACKS * SECTORS_PER_TRACK * SECTOR_SIZE; int directory_end = directory_start + DIRECTORY_SIZE; int extent = 0; for (extent = directory_start; extent < directory_end; extent += 32) if ((data[extent + 1] != 0xe5)) { /* CP/M names are stored as 8 name and 3 extension char, padded with spaces */ int despace = 0; char unix_name[13]; sprintf(unix_name, "%.8s.%.3s", data + extent + 1, data + extent + 9); for (despace = 0; unix_name[despace]; ++despace) { unix_name[despace] = tolower(unix_name[despace]); if (unix_name[despace] == ' ') { memmove(unix_name + despace, unix_name + despace + 1, strlen(unix_name + despace)); --despace; } } int file_size = (data[extent + 12] * 16384) + (128 * data[extent + 15]); printf("%02x %6d %12s ", data[extent], file_size, unix_name); /* Open output file if copying files */ descriptor = -1; if (copy_files) if ((descriptor = open(unix_name, O_WRONLY | O_CREAT | O_TRUNC, 0664)) < 0) fprintf(stderr, "%s: %s\n", unix_name, strerror(errno)); /* Traverse list of blocks */ int block; for (block = 0; block < 16; ++block) if (data[extent + 16 + block] > 0) { int block_number = data[extent + 16 + block] - 1; int offset = (SECTOR_SIZE * SECTORS_PER_TRACK * SYSTEM_TRACKS) + DIRECTORY_SIZE + (ALLOCATION_BLOCK_SIZE * block_number); int block_size = ALLOCATION_BLOCK_SIZE; if (block_size > (file_size - (block * ALLOCATION_BLOCK_SIZE))) block_size = (file_size - (block * ALLOCATION_BLOCK_SIZE)); printf("%02x ", block_number); if (offset > length) printf("(Invalid block) "); else if ((descriptor > 0) && (block_size > 0)) write(descriptor, data + offset, ALLOCATION_BLOCK_SIZE); } printf("\n"); } return 0; }