Upgrading early BIOS

Fred Cisin asked (1) Yes I did. (2) The BIOS screens give the following drive selections The following abbreviations are used in the table: Cylinders: CYL Heads: HDS Write Precomp: WP Landing Zone: LZ Sectors: SCT MegaBytes: MB Disk Type CYL HDS WP LZ SCT MB 1 306 4 128 305 17 10 2 615 4 300 615 17 20 3 615 6 300 615 17 30 4 940 8 512 940 17 62 5 940 6 512 940 17 46 6 615 4 -1 615 17 20 7 462 8 256 511 17 30 8 733 5 -1 733 17 30 9 900 15 -1 901 17 112 10 895 15 -1 895 62 406 11 1054 16 -1 1054 63 518 12 855 7 -1 855 17 49 13 306 8 128 319 17 20 14 733 7 -1 733 17 42 15 There is no listing for this drive type 16 987 12 -1 988 35 202 17 977 5 300 977 17 40 18 977 7 -1 977 17 56 19 1024 7 512 1023 17 59 20 880 11 0 0 17 81 21 903 8 0 0 46 162 22 1024 16 0 0 17 136 23 914 14 0 0 17 106 24 1001 15 0 0 17 124 25 977 7 977 977 26 86 26 1024 4 -1 1023 17 34 27 1024 5 -1 1023 17 42 28 1024 8 -1 1023 17 68 29 980 10 980 990 17 81 30 1024 10 0 0 17 85 31 832 6 832 832 33 80 32 1020 15 -1 1024 17 127 33 776 8 0 0 33 100 34 1024 12 0 0 17 102 35 1024 9 1024 1024 17 76 36 1024 5 512 1024 17 42 37 830 10 -1 830 17 68 38 823 10 256 824 17 68 39 980 14 -1 990 30 200 40 615 8 128 664 17 40 41 917 15 -1 918 17 114 42 1023 15 -1 1024 17 127 43 823 10 512 823 17 68 44 820 6 -1 820 17 40 45 1024 8 -1 1024 17 68 The BIOS also allows two User-Defined Types, in which the parameters can have the following ranges: Cylinders: 0-9999 Heads: 0-99 Write Precomp: 0-9999 Landing Zone: 0-9999 Sectors: 0-99 The machine will not recognize ANY second drive. The drives I have tried are all consideraby bewer than the BIOS and I just can't think of any other reason why they would not be recognized. I have tried the "cable select" settings on all of them. I assume that the MASTER/SLAVE methodology is not mandatory. Can someone suggest a good book that goes into this type of thing? Thanks, Kurt