At 01:15 PM 3/26/2004 +0200, you wrote: >On Thu, 25 Mar 2004 23:45:13 -0600, Michael Devore wrote: > >>Second problem report: UDMA. Unfortunately UDMA 7.0 fails on my system across the >>board, although it finds the controller and identifies it plus the two drives. >>Under both HIMEM with and without EMM386, all four DMA tests fail and the driver >>does not load. Under a bare conventional memory system without HIMEM (or EMM386 >>obviously), UDMA kicks out an illegal opcode or locks the machine in a "missing >>command interpreter" loop. So, the sad state of affairs is that any EMM386 >>incompatibility with UDMA is going to stay since UDMA doesn't work for me. > >UDMA requires VDS in V86 mode. Without XMS driver it can't do its tests and loads but >fails.
HIMEM gives XMS without V86, so it theoretically should work in that situation. For no HIMEM, UDMA doesn't say it doesn't work without an XMS driver and the ASM comments say that "DMA only" supported was added in version 1.7 for non-XMS environments. The UDMA.ASM code appears to support that remark. Perhaps the support is missing, but seems like crashing the machine is a bit more unfriendly than what is intended. VDS with EMM386, I didn't know how or if it would work. When I looked at the UDMA code, it appeared to check for a VDS flag and existence call that EMM386 would not have set and I thought it might work on its fallback to non-VDS mode. >What version of TASM do you use? I haven't had LGDT problems with TASM 5.3 dated >30.V.2000. Version 2.5. It's either a free downloaded version or, more likely, the original version of TASM from my DOS development days. Probably close to the last major update they had for DOS. ------------------------------------------------------- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click _______________________________________________ Freedos-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/freedos-devel
