GT for DOS Evaluation Pack - README.TXT ========================================== Thanks for your interest in GT. This file contains instructions for the GT for DOS evaluation. If you're reading this, you've probably already unpacked the archive file, and you should have the following programs: * GT32.EXE (32-bit GT Compressor) * UNGT32.EXE (32-bit GT Decompressor) * DOS4GW.EXE (32-bit DOS Extender for the above programs) GT is a PKZIP-like utility used to compress files to a fraction of their original size. GT is optimised for maximum decompression speed, and is particularly useful for developers of CD-based products. It also features a very simple API (just two functions) and a unique memory-saving decompression process which avoids the need for separate data buffers. Note that, for simplicity, GT doesn't generate archive files - it just concentrates on squashing individual files as much as possible. This evaluation pack provides all you need to test GT on a PC - to use GT in a retail product, you need to purchase a GT decompression library (DOS / Win 3.1 / Win 95 / Win NT / PSX / Saturn). 'C' and assembler source code versions are also available - contact ATD for pricing and ordering information. Note that the GT utilities supplied are 32-bit; i.e. they require at least a 80386 processor in order to run. GT32 Command Line Parameters ============================ ATD GT32 File Compressor Version 2.11 - (C) 1995,1996 Usage: GT32 [-b|l] [-p#] [-x] [-h] may include wildcards -b - Output file in big endian format -l - Output file in little endian format (default) -p# - Pad data at front so file is multiple of # bytes -x - Maximum compression -h - Display this help screen ---------- This specifies the files you wish to compress - wildcards are accepted. The output file name(s) are the same as the input one, except that the file extention is .GTO - take care to ensure that no two input files have the same first 8 characters! -b - Output file in big endian format -------------------------------------- The compressed files will be output in 'big endian' or Motorola format, storing the most significant byte first, and least significant byte last. This is the native format for the Mac, and most games consoles. -l - Output file in little endian format (default) ----------------------------------------- The compressed files will be output in 'little endian' or Intel format, storing the least significant byte first, and most significant byte last. This is the native format for the PC. -p# - Pad data at front so file is multiple of # bytes ------------------------------------------------------ In order to optimise loading from CD (which tend to load data in fixed sized chunks), unused data can be placed at the start of the file so that the file size becomes a multiple of # bytes. For PC CD-ROMs, # = 2048 bytes. -x - Maximum compression ------------------------- Maximum compression may be gained by specifying this switch. Note that although this may increase compression time, decompression time will not rise - indeed, if the resultant file size is smaller with maximum compression, the decompression time should be reduced. UNGT32 Command Line Parameters ============================== ATD GT32 File Decompressor Version 2.11 - (C) 1995,1996 Usage: UNGT32 [-c] [-p#] [-o] [-h] may include wildcards -c - Decompresses using C rather than pure 80386 -p# - Pentium timings where # is processor speed in MHz -o - Test overlapped decompression -h - Display this help screen ---------- This specifies the files you wish to decompress - wildcards are accepted. These files should be .GTO files, produced by the GT32 compressor. The output file name(s) are the same as the input one, except that the file extention is .TST - take care to ensure that no two input files have the same first 8 characters! -c - Decompresses using C rather than pure 80386 ------------------------------------------------- UNGT32 contains two separate but functionally equivalent decompression routines - one written in 'C', the other in assembler. This switch (when used in conjunction with -p#) allows you to monitor the decompression performance using the 'C' code (which is available separately). -p# - Pentium timings where # is processor speed in MHz ------------------------------------------------------- Allows you to monitor the decompression performance (for Pentium machines only!) by counting the number of cycles that the processor takes inside the decompression routine. -o - Test overlapped decompression ----------------------------------- Overlapped decompression is when the compressed data is decompressed 'over itself' in order to minimise memory requirements. This option allows you to make sure that decompressing in this manner is successful. Attention To Detail Ltd Unit 3 Nunhold Business Centre Dark Lane Hatton Warwickshire CV35 8XB United Kingdom Tel: +44 (0) 1926 843444 Fax: +44 (0) 1926 843363 E-mail: info@atd.co.uk