Jack, Bret, VirtualBox users, > A favorite tactic of "propagandists", be they Fascist/Nazi/Communist > or others, is that they flatly IGNORE any information from opponents
At this point, you lost the discussion and many readers will simply have skipped the rest of your mail, as explained here: http://en.wikipedia.org/wiki/Godwin%27s_law#Corollaries_and_usage > In responding to the above thread, you have totally IGNORED all info > I offered to begin with, and you cite, as your reference, a 1991 IBM > Technical Reference for the PS/2. No. The point was that BIOS Central, RBIL, Tischer and other reputable sources disagree* about 40:8f and therefore, even though each individual source is reputable, 40:8f is not a safe way to decide about floppy change lines. On the other hand, all sources do agree about int 13 for that purpose. * can mean ONE thing, ANOTHER thing, or be a RESERVED byte. > (C) As of 11-Jan-2007, 16 years PAST your IBM reference, Phoenix and > maybe other BIOS vendors do in fact support byte 0:048Fh exactly The weak point is in "maybe other" here. > (D) UIDE/UIDE2 have NEVER failed, to my knowledge... on any actual > "hardware" PC system. If so, I want to KNOW about it... Virtual machines are widespread now, their users deserve support. > (E) VirtualBox handling of diskette change-lines IS IN DOUBT! The comment in orgs.asm indeed supports your claim that VirtualBox is in conflict with itself IF 40:8f really means what UIDE thinks. However, documentation about that very byte is contradictionary... Also, DOSEMU treats the same byte as reserved (0) and is backed by literature for this. As long as you can find support in literature for multiple interpretations of the same byte, it is not safe to "demand" from all BIOSes to interpret the byte in one specific way. Note that I was not able to download rombios.c from "BIOS" so all statements about me reading VirtualBox sources are limited to the "BIOS-new" directory and I do not know which version is used when. > Use UIDE/UIDE2 if you think they work. Otherwise, do not use them. The third choice is giving my "prosthetic" helper a try ;-) Users of VirtualBox and UIDE, but also of other systems including real hardware, are invited to write me off-list, so I can send a copy and receive feedback :-) My tool does the following: It installs a PCI BIOS handler where scans are limited to existing bus numbers (VirtualBox has 1 bus but VirtualBox BIOS scans 256) which should speed up UIDE init a lot. This function is an experimental TSR and takes circa 400 bytes of DOS RAM. Loading into UMB with LH should be possible without problems. The other function does not take any DOS RAM: It simply enforces the expected-by-UIDE semantics for the BIOS Data Area byte 40:8f - This should protect you from data loss in VirtualBox and should enable UIDE caching of floppies in DOSEMU. Regards, Eric :-) ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
