*** Binary *** Document revision 1.1 This is really a non-format, as it has no specific layout whatsoever, but instead is simply a data file. This does make it difficult to describe any general layout, as there are many possibilities. It is assumed that a binary is a single file, usually having no special extension (like LNX/SFX/SDA, etc), sitting on a PC hard disk, not inside of *any* other file (like in a D64/T64/LNX etc). By looking at the whole file (but especially the beginning) with a HEX editor, and a well-trained eye, you can usually determine what file type it is by the BASIC code, load address, and text strings contained within. If the file is a normal C64 program, then the first two bytes are the load address, stored in low/high byte format. If it is a BASIC program (or has a BASIC header), then the first two bytes might be $01 $08 (or $01 $04 for PET, $01 $1C for C128, the numbers vary for different systems like VIC-20, Plus4, C61, etc), and the rest is line number pointers, line numbers and BASIC code. If it is not a BASIC file (like part of a game loader), then it could be a machine language file, requiring a SYS call to execute. Many secondary files with multi-file games have load addresses other than $0801 (like $C000, or $8000 for cartridges), and some have none at all, where the loader program will actually specify where to load the file. Below is a typical header for a game, using a SYS call to start (in this case, SYS 2064). 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F ASCII ----------------------------------------------- ---------------- 0000: 01 08 0E 08 E9 03 9E 20 28 32 30 36 34 29 00 00 .....(2064) 0010: 00 78 A2 FF 9A A0 00 84 01 A2 CC BD 57 08 9D 33 x.̽W.3 One reason this non-archive format is important is because of the filename limitations imposed by the PC architecture, and some of the problems that it can cause. The PC has an 8.3 filename convention (assuming DOS, and not OS/2 or Windows 95/NT long filenames), allowing for, at most, a filename of 11 characters. The PC also has character limitations on filenames, most of which don't apply to the C64. When converting a C64 file from any emulator file, you *cannot* use the C64 filename directly on the PC since, first of all its likely too long, and secondly it may contain characters illegal in the DOS world (i.e. ASCII 46, the 'extension' separator). One other reason that binary is not a good way to keep C64 files is that you lose the C64 filetype. You *can* set the file extension to show the type (xxx.PRG, xxx.SEQ), but this is not typically done. If the DOS extension is not set, it is much more difficult to know what format the file originally was. In order to convert a filename from C64 to DOS, the use of translate tables (translating illegal characters to legal ones) as well as an algorithm to reduce the filesize down to useable size (typically only 8 characters from 16) must be used. Included within the PC64 distribution archive is a 'C' program which does just what I have described. It contains an algorithm which will remove illegal characters, then reduce the filename down using several different rules, all to make the filename conform to the DOS 8.3 naming standards. There are some people who feel that with Windows95 (or OS/2, or Windows NT) long filename support, we should be able to have C64 files with the full 16 character filename on the PC hard disk. This is a fallacy as the useable character limitations of the C64 and those of any OS supporting long filenames are not the same. If you convert a C64 filename, many characters must be removed and or changed to allow it to be used in DOS (or Win95). There is very little benefit or disadvantage to using binary. About the only thing which is important to remember is you could lose most of the original C64 filename, which *will* cause problems when you try to reconstruct them. Binaries have no way of preserving the actual long names. --------------------------------------------------------------------------- Overall Good/Bad of BINARY Files: Good ---- * Easily determined filesize (the DOS filesize is the C64 filesize) * It is the *native* C64 file, so emulators can *easily* support it Bad --- * No 16 char filename, no real C64 filename at all * No filetype, or special attribute bits * No REL, GEOS or FRZ file support * No signature or file description * Difficult to support multi-file, as original C64 filenames are not retained * Since there is no filetype, you may not always be able to determine if the file is a SEQ, USR or really a PRG without knowledge of the file contents