Hi all... some mixed replies on this thread: > http://fd-doc.sourceforge.net/spec/
> (2) I don't think MS-DOS 5.0 is an improvement over 3.3... It *is* an improvement - it adds HMA and UMB support. And DOS 6.xx used more or less the same kernel as DOS 5.00, while 5.00 is quite different from earlier versions it seems (rewritten in ASM or so). So the reference DOS for us should be 5.00, and we can try to add clones for the TOOLS which MS added (often bought from 3rd parties) to make 6.xx look like an improvement over 5.00 ;-). > (3) The forcing of 8088/80286 should perhaps become "strongly > recommended" and not "mandatory" Okay with me, but should be WELL DOCUMENTED. And I would really like programs to show error messages instead of CRASHING on pre-386 systems. For example the caches follow that recommendation, but for example HIMEM / EMM386 are compressed with something which has a stub starting with "jmp short x ; ... ; call y ; y: pop bx ; sub bl,bl ; push bx ; pusha ; sub al,al ; jmp z ; ..." in EXE mode and with something which sets other AL / pushed values before the PUSHA in SYS mode. So trying to start them on pre-186 would just crash. OKAY for me, as people should KNOW that XMS is only possible on 286/better and that EMM386 needs a 386, but would be nice to have a list with cases like that somewhere. Question to Tom, author of that sys/exe packer: Does the stub work on 286? If so, then emm386/himem should abort with a warning when you try to run them on a 286. If not, then people with a 286 will get an "unexplained" crash - then it would be nice to have a 286- compatible version of the sys/exe packer stub. No need for an 8086- compatible (without PUSHA) version in THAT case, as, again, people should KNOW that 8086 has no XMS. > Good point, FreeDOS would make a great alternative to WinXP DOS box, > for true compatibility ... but out of curiousity how do those games run > on such a (assumingly) fast CPU running Window XP? I found that many of my games give runtime error 200 on a Pentium III with 866 MHz unless you throttle (FDAPM SPEEDn) to 1/8 or 2/8 of max speed. However, almost all games work with my K6-2 500 MHz. Part of the reason is that the K6-2 has only 200 MBy/s memory bandwidth, while the Pentium III has twice as fast memory access. Actually, Pentium III has almost Pentium M (see "Centrino" stuff) kind of power-per-MHz, more than Pentium 4, and can run with small power consumption... You cannot throttle below 1/8 (on some motherboards 1/16) of max speed in hardware, so you would need to load other speed eaters like MoSlo, SLOWDOWN or the RTC-based one from the same page where you get THROTTLE: http://www.oldskool.org/pc/throttle/ ... In short, if your system has more than 1 GHz CPU clock, then the best way to run DOS games will probably be using a virtual computer in a window, e.g. DOSEMU or DOSBOX. The latter does not even need FreeDOS :-|. > If you read my original message, my 286 was crashing when I used > FDXMS286 which is why i was talking about HIMEM/286... Users of 286 are very rare by now. Even mobile phones support Java these days, so you should assume that every toaster has a 386 or better CPU X-). However, our specs tell that we want 8086 compatibility, and I found that many tools do not get much bigger or slower if you compile without the optimizations that 386 allows. Many, but not all. It is good that the caches and HIMEM/EMM386 are 386+ only, and it is good that the FAT32 kernel is by default optimized for 386 (this saves a few kilobytes, as FAT32 works much better if you can use 32bit variables in optimized way). However, it is cool that we CAN boot in FAT32 mode on an 8086... Generally it is nice to have all tools run on minimal hardware: You simply CANNOT have 386ish EMS without a 386 (EMS was first some add-on hardware thing for 8086, and games used that back in ancient times when gamers had not enough bucks for a 286 with XMS, I guess). You CANNOT have XMS on a pre-286 either, and therefore everything which needs XMS can assume that a 286 or better CPU is present. EMS is often worse performance-wise, and it would be over- doing things to write EMS/8086 versions of tools which already do exist with XMS support even though that needs a 286. My excuses that the caches even need a 386 although a 286 version would be possible for people with enough XMS on their 286... On the other hand, those can check out several free- and shareware caches described in CACHES.TXT in the LBAcache download... Again, all a DOCUMENTATION issue. If somebody happens to have an 8086 with CD-ROM, then it is interesting to know whether we can support that. As far as I know, Jason can do 8086 compiles of SHSUCDX by now, but I have no idea which *CDROM*SYS drivers can or cannot work on 8086. I found that at least SOME versions of MS CHKDSK refuse to do FAT32, pointing you to scandisk - OUR CHKDSK can do the same, pointing to Lucho's freeware CHKDSK32 or our DOSFSCK port, which both need a 386 CPU as far as I know. Being able to do EVERYTHING on 8086 is, again, overdoing things. Being able to do MOST, however, is cool for people who show off with running EzNoz servers on PC-XT. Eric PS: Please disable HTML mail when posting to the list... PPS: Anybody knowing why LOADFIX is disabled in XMS-swap FreeCOM? I have the idea that you only NEED LOADFIX when you have an HMA/XMS at all. For those programs which are buggy enough to need loadfix at all, that is. ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click _______________________________________________ Freedos-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/freedos-devel
