PGOETZ@LOYVAX.BITNET (01/12/88)
Apple disk format: Somebody with a Commodore asked about Apple's disk format. You'd better get Beneath Apple DOS to explain it in full. The most important difference is that DOS 3.3 uses 6&2 encoding to convert 342 bytes of the 69 valid disk bytes into 256 bytes. Writing ctrl-D to a text file: Here's a sneaky way: Ctrl-D is simply the character chosen to flag DOS commands. A routine in DOS scans text for this character. You can use a POKE to change this character to, say, ctrl-E, write the ctrl-D, then change it back to ctrl-D. In DOS 3.3, $84 (ctrl-D) is at $AAB2 (43698). So a POKE 43698,133: ?CHR$(4);: POKE 43698,132 would probably do the trick. I don't know the location in ProDOS; scan it for $84. VT100 emulators: Does anybody have one that'll play Rogue & Conquest? Woz & DOS: Woz stated in a Call-APPLE (or Apple Orchard, I forget) interview years ago that when writing DOS, he kept losing track of the program and having to start over each newc programming session. Finally he spend one whole weekend on it & wrote the durn thing. Printing Backwards: My Olivetti ink-jet printer (which is, BTW, surely the worst printer ever made) has a motor to move the print head back & forth. 1 red & 1 black wire go from this motor to the circuit board. I found that if I switched these two wires, the motor turned opposite of how it should, thus printing backwards. Not siht ekil tsuj, but a true mirror image. Neat effect, possibly useful for getting mirror-image hi-res dumps. Smart-ass programs: The programs I hate the most are those that think they're smarter than I am. Apple Writer II+ and ProDOS Convert fall into this category. Apple Writer doesn't believe my disk when it claims some files live on tracks beyond $22. But instead of just giving an error message, AW just leaves out those parts of the files when loading them in. Either that or pretends the whole file is empty; the files I've had this problem with have resided entirely beyond track $22. Anyway, this is a big problem for me. Does anyone know a patch to Applewriter II+ to solve this (and for that matter, how to deprotect AW II+?) Convert gives me trouble because when I want to move a file from one of my modified DOS 3.3 disks to ProDOS, it says ERROR: NOT A DOS 3.3 VOLUME. Does anyone know how to override this so I can move files from disks with my DOS on them onto ProDOS? I scanned my ProDOS 1.0.1 master for the ASCII sequences NOT A DOS 3.3 and 3.3 SOD A TON, high & low ASCII, but they're not their. (I suspect Convert uses the same text compression method as ProDOS; I haven't looked for this yet.)