= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = The MegaDisk (tm) Disk Format Translation System Copyright (C) 1985,1986 Paul Bartholomew All Rights Reserved = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = NOTICE ====== MegaDisk may be freely copied between owners of the AMPRO Little Board computer, as long as it is not sold. Prior written permission from the author is required before you may commercially distribute MegaDisk. Description of MegaDisk: ======================== MegaDisk is a powerful disk read/write system for the AMPRO Little Board series of computers. It is intended to supplement MULTIDSK and ESET. Eventually, MegaDisk will allow formatting different formats, but for now it will only read and write them. MegaDisk can be EASILY expanded without any knowledge of assembly language. It is based on a set of files called disk definition files. You can add and delete these files as you wish to make a "custom" MegaDisk. Currently, MegaDisk comes with 61 disk definition files. Getting the MegaDisk System up and running: =========================================== To use MegaDisk, you'll need the following files: MGD-x-y.OBJ MEGADISK.LBR MGD-x-y.OBJ is the MegaDisk program ('x' is the version number, and 'y' is the revision number. Version 1.4 of MegaDisk would be called 'MGD-1-4.OBJ'. After you get MGD-x-y.OBJ, rename it to MEGADISK.COM. MEGADISK.LBR needs to be present when MegaDisk is run, because all of the disk definition files are within it. MEGADISK.LBR can be present anywhere along the MEGADISK search path (discussed below). Running MegaDisk: ================= Execute MegaDisk by typing MEGADISK followed by a carriage return at the CP/M prompt. After displaying a copyright message, MegaDisk will let you know that it's reading in all of the disk format names by saying: 'Reading disk parameter files...'. MegaDisk will also update the display while reading the names by printing the total number of names read so far. After all of the names have been read, the MegaDIsk Main Menu will be displayed. Below is an example Main Menu: ============================================================================== MegaDisk -- Foreign disk read/write utility Version 1.4 for the AMPRO Little Board computer Copyright (c) 1986 by Paul Bartholomew - 01/21/86 ------------------------------------------------------------------------------ ***************************** MegaDisk Main Menu ***************************** 1. MegaDisk single sided disk format sub-menu # 1 (15) 2. MegaDisk single sided disk format sub-menu # 2 (15) 3. MegaDisk single sided disk format sub-menu # 3 (8) 4. MegaDisk double sided disk format sub-menu # 1 (15) 5. MegaDisk double sided disk format sub-menu # 2 (6) 6. MegaDisk 96tpi disk format sub-menu (2) Enter a sub-menu number, or ESC to exit : __ ============================================================================== The number in parentheses after the sub-menu title is the number of disk formats within that sub-menu. To select a sub-menu, enter the sub- menu number followed by a RETURN. If you decide you want to exit MegaDisk instead, you can press the ESC key (without a RETURN) to end the program. After you select a sub-menu number, MegaDisk will clear the screen and display a list of all the formats in that sub-menu. Below is an example sub-menu format list: ============================================================================== MegaDisk -- Foreign disk read/write utility Version 1.4 for the AMPRO Little Board computer Copyright (c) 1986 by Paul Bartholomew - 01/21/86 ------------------------------------------------------------------------------ *************** MegaDisk single sided disk format sub-menu # 1 *************** 1. AMPRO Little Board (SS DD 48tpi) 2. Access Matrix (SS DD) 3. Bondwell 12 (SS DD) 4. Cromemco CDOS (SS SD) 5. Cromemco CDOS (SS DD) 6. Cromemco Intl Term CPM (SS DD) 7. DEC VT180 (SS DD) 8. Heath (SS SD) 9. Heath w/Magnolia (SS DD) 10. Heath/NEC (SS DD) 11. IBM PC (CP/M-86 SS DD) 12. IMS 5000 (48 tpi SS DD) 13. Kaypro II (SS DD) 14. LOBO MAX-80 (SS DD) 15. Morrow Micro Decision (SS DD) Enter a format number, or ESC to go to Main Menu : __ ============================================================================== At this point, you can press the ESC key to return to the main menu, or enter the disk format number that you want to read/write, followed by a RETURN. When you enter the format number, MegaDisk will read in the disk definition file from disk. If it doesn't find it, it will tell you the name of the file it was looking for, and ask you to press RETURN. After you press RETURN, you will be returned to the sub-menu format list. After you enter the format number, MegaDisk will ask you which drive you want to be assigned to that format when you call it drive E, and will show you the valid drive names that you may enter, for example: 'Select a drive (A,B,C,D) to use as the E-disk : _' The above question tells you that the valid drives you may enter are either A, B, C, or D. You may press ESC at this question to return to the disk format sub-menu. After you enter the drive name, MegaDisk will ask 'Enable double-step bit? (Y/N) _'. Enter a 'Y' to enable double-stepping, or anything else to disable it. You may press ESC at this question to return to the disk format sub-menu. Answer 'Y' only if the drive you selected is a 96 track per inch (tpi) drive AND the format you selected is 48 tpi, otherwise answwer 'N'. After you answer the double-step question, MegaDisk will inform you that the drive you selected will be the format you selected when you call it drive 'E'. If you enabled double-stepping, MegaDisk will also tell you this. After that, MegaDisk will return to CP/M, and you can use the selected format in the selected drive when you access it as drive 'E'. MegaDisk quick entry mode: ========================== The MegaDIsk quick entry mode allows you to specify parameters on the command line instead of entering them one-by-one as MegaDisk asks you for them. To use the quick entry mode, specify the parameters in the following form: MEGADISK m f d s Where 'm' is the sub-menu number, 'f' is the disk format number, 'd' is the disk drive that will be assigned to the new format when you call it drive E, and 's' is the "double-stop mode" respones. 's' will be Y if you want double-stepping enabled, or anything else to disable double-stepping. Below is an example: MEGADISK 4 13 b n The above command (when used with the distributed MEGADISK.LBR) will select sub-menu number #4 (MegaDisk double sided disk format sub-menu # 2), disk format #13 (Morrow Micro-Decision DS DD), and will select drive B as the drive to be assigned to the new format when you call it drive E. Since 'n' was the answer for double stepping, double stepping will be disabled. Modifying the disk formats: =========================== MegaDisk looks at the file MEGADISK.DAT for a list of filenames that hold the disk definitions. MEGADISK.DAT is within the library MEGADISK.LBR. If you wish to modify the list of formats, you will need to use a library utility (LU, NULU, etc.) to extract MEGADISK.DAT from the library. Once you have extracted MEGADISK.DAT from the library, use a text editor (in non-document mode) to modify the file. MEGADISK.DAT file structure: ============================ MEGADISK.DAT contains a list of filenames which hold the disk definitions. After each filename, there is an equal sign ('=") and the name of the disk format. Lines that start with a semi-colon (';') are considered to be comment lines and are ignored by MegaDisk. A line that starts with a period ('.') defines a sub-menu title. MegaDisk automatically inserts a sub-menu title after every 15 disk formats, but you can override this by placing your own sub-menu titles in MEGADISK.DAT. Below is a sample MEGADISK.DAT file: ;This is a comment line that is ignored by Megadisk ; ;Below is a sub-menu title: ; AMPSS48.DSK = AMPRO Little Board (SS DD 48tpi) ACCES-SS.DSK = Access Matrix (SS DD) BONDWLSS.DSK = Bondwell 12 (SS DD) ; ;Below is another sub-menu title: ; NEC80SS.DSK = NEC PC-8001A (SS DD) OSB1SSSD.DSK = Osborne One (SS SD) OSB1SSDD.DSK = Osborne One (SS DD) OSBOSMSS.DSK = Osborne Osmosis (SS DD) You must follow all filenames by an equal sign and the name of the disk format. The name you use here is what is displayed on MegaDisk's sub-menu format list. If you ran MegaDisk using the above MEGADISK.DAT file, the main menu would look like this: ***************************** MegaDisk Main Menu ***************************** 1. MegaDisk single sided disk format sub-menu # 1 (3) 2. MegaDisk single sided disk format sub-menu # 2 (4) As you can see, the sub-menu titles are used on the MegaDisk main menu to segregate different groups of formats. The number in parentheses after the sub-menu title is the number of formats in that sub-menu. If you don't specify any sub-menu titles in the MEGADISK.DAT file, MegaDisk will automatically insert one after every 15 formats, with the form: 1. MegaDisk sub-menu # 1 (15) Again, the number in parentheses is the number of disk formats within that sub-menu. MegaDisk disk definition file structure: ======================================== Below is the structure of a disk definition file. After you have created a new file, be sure you add that filename to the list of filenames in MEGADISK.DAT. NAME = Name of disk SPT = Number of CP/M sectors per track BSH = Block shift factor BLM = Block mask EXM = Extent mask DSM = Disk size in blocks - 1 DRM = Number of directory entries AL0 = Allocation unit 0 AL1 = Allocation unit 1 CKS = Number of "checked" directory entries OFF = Number of reserved tracks SKEW = Sector skew table seperated by commas (',') DENSITY = Density, either 1 or SINGLE for SD, or 2 or DOUBLE for DD SIDES = Sides, either 1 or SINGLE for SS, or 2 or DOUBLE for DS SECTORM = Sector numbering on side 2, either SAME or CONTINUOUS TRACKM = Track numbering on side 2, either DOWN (normal), or UP ALLOC = CP/M allocation unit - 1K, 2K, 4K, or 8K SECSIZE = Physical sector size - 128, 256, 512, or 1024 Numbers in the disk definition file may be in either decimal (default), or hexadecimal. Enter a hexadecimal number by following it with the letter 'H' (28H for example). Refer to the included disk definition files for examples. MegaDisk search path: ===================== MegaDisk requires two files for its operation. The first is the index file, usually called MEGADISK.DAT. The second is the disk definition for the selected format, having names of the form AMPDS48.DSK. A search path is used whereby MegaDisk looks for these two files first outside of a library (e.g. MEGADISK.LBR), then looks for them inside the library. In addition, MEGADISK performs this in a sequence of user areas. The usual search path is: (d=current drive, u=current user) 1. du:filename 2. du:MEGADISK.LBR\filename 3. d0:filename 4. d0:MEGADISK.LBR\filename 5. d15:filename 6. d15:MEGADISK.LBR\filename 7. Au:filename 8. Au:MEGADISK.LBR\filename 9. A0:filename 10. A0:MEGADISK.LBR\filename 11. A15:filename 12. A15:MEGADISK.LBR\filename In the above sequence, "MEGADISK.LBR\filename" represents obtaining the required data file from within the library. As can be seen, the MegaDisk format data base can be modified by placing a revised index file (MEGADISK.DAT) and additional (or modified) format definition files (.DSK files) outside of the MEGADISK.LBR main file. This was done to make it easy to enhance the system without having to modify the main library. In addition, you can simply place a shortened index file (MEGADISK.DAT) along with one or more format definition files (.DSK files) on your system disk, rather than including the entire library. Finally, a utility called MGDINST.COM allows you to modify the above search path if you choose to do so. When you run MGDINST.COM, simply respond to the program's prompts. = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = MegaDisk - Copyright (c) 1986 Paul Bartholomew = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =