Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!magnus.acs.ohio-state.edu!tut.cis.ohio-state.edu!ucbvax!FRP8V11.BITNET!MONTARON From: MONTARON@FRP8V11.BITNET (Alexandre Montaron) Newsgroups: comp.os.cpm Subject: About Amstrad' Bios bug | Message-ID: <9103220804.AA26926@ucbvax.Berkeley.EDU> Date: 22 Mar 91 00:48:49 GMT Sender: usenet@ucbvax.BERKELEY.EDU Organization: The Internet Lines: 25 Hello| I'm happy (in fact no) that someone else has found the bug... which replace a good sector (a CPM's block of 128 bytes) by anything else... But if you typed ^C (equal to Bdos fnct number 13) it will work perfectly| I thought it is because of my ram-disk (DK'tronics 256Ko)... because one of my friend has a CPC w/o ram-disk and all work well| I've a clue about the bug All read & write disk access pass throught buffer (see BCB=Buffer Control Blk) There's at all 32Ko of buffer (as tou can call cache disk|) located on bank number 2 if i remember well. If the patch of the ram-disk alter this area it will bug when CPM attempt to save this block (perhaps it's the patch itself|) Because ^C flush (but not save) all buffer to disk... I think the answer is near | Make a list of BCB, search buffer & verify content of all buffer... to solve the bug you have to minimize buffers... It's my opinion... What do YOU thing of this ? I've the OPERATOR's AND PROGRAMMER's GUIDE for the AMSTRAD CPC6128 & PCW8256 by Digital Research Inc. & Amstrad Consumer Electronics plc... it's a very good book but it doesn't talk about the BIOS... and BCB (buffers) are manage by the BIOS (see also DPH=Disk Parameter Header... which contain a pointer to the first BCB...) I've an other book which talk about the BIOS but it's very short | Does someone have a better book which talk about programming (not using|) CP/M+ include BIOS part please... Thanks... I hope i've forgetten anything... Alex Montaron