From: utzoo!decvax!ucbvax!C70:info-cpm Newsgroups: fa.info-cpm Title: CP/M Blocking and Deblocking Article-I.D.: ucb.1422 Posted: Fri Jun 25 21:19:15 1982 Received: Mon Jun 28 06:37:11 1982 >From ucivax!csuf!bruce@Ucb-C70 Fri Jun 25 21:18:52 1982 Are there any known bugs in the sector blocking/deblocking algorithms supplied by Digital Research with CP/M? I don't mean the field patch that DR distributes (the one you make to MOVCPM). I've already installed that one. My problem is this: ONLY when running the CP/M editor 'ed', files larger than one extent (128 records, in my system) end up garbled. What happens is a sector from the NEXT extent ends up replacing the corresponding sector in the PREVIOUS extent. This continues throughout the whole file. NONE of the other programs I have, CP/M-supplied or otherwise, do this. I have one clue; when I patch the BIOS to jump around the code that checks for a write to an unallocated block, the problem goes away. I have checked and rechecked the code that is being skipped over, and I can't find anything wrong with it. The code in question is between the labels 'chkuna:' and 'alloc:'. I'm using exactly this code in my BIOS. Has anyone else had a problem similar to this one? Bruce ucbvax!ucivax!csuf!bruce