Hi, > You should have mentioned something about the context > instead of only throwing URLs at us ;-). The first URL > talks about making more low RAM free by loading things > high into UMB and by using fewer drivers. The second > URL talks about DR DOS. One thing that might be useful > for FreeDOS and JEMM is the EMM386 hint in the first: > It says you might be able to use: > > EMM386 ... I=B100-B7FF I=C600-C7FF I=CC00-CFFF I=e600-efff > > In other words, the Virtual PC VGA BIOS is only 24k
it is 48 kB (C000-CBFF), but has holes. Using I=TEST finds most of them automatically, except the 4 kB region C700-C7FF (because it has a different "last byte"). OTOH, region CC00 seems to be not really free on VPC 2007, it contains a 2 kB ROM. Jemm somehow has the opinion that this region is free, however, I don't know why. To be safe, it should be excluded with X=CC00-CCFF. > and the mono text mode buffer can be partially used > for UMBs (b100-b7ff). My experience tells that the buffer can be fully used (B000-B7FF) > Unfortunately it does not tell which > things are in the way at e000-e5ff and c800-cbff, do you > know more about that? Tool GetI15Ex (hxrt) displays: Int 15h, eax=E820h: addr 000000000, size 00009FC00, type 1 (available) addr 00009FC00, size 000000400, type 2 (reserved) addr 0000E0000, size 000020000, type 2 (reserved) addr 000100000, size 001EF0000, type 1 (available) addr 001FF0000, size 00000F000, type 3 (ACPI) addr 001FFF000, size 000001000, type 4 (ACPI) which tells that region E000-EFFF is NOT free. Examining it with DEBUG confirms this. So a "good" Jemm line for VPC 2007 might be: DEVICE=JemmEx.exe NOINVLPG NOVME FASTBOOT I=TEST I=B000-B7FF I=C700-C7FF X=CC00-CCFF It will then install an EMS frame buffer in D000-DFFF. If EMS is not needed, the NOEMS will add 64 kB UMB. What should be mentioned with VPC's Guest Additions: the binary VMADD386.SYS must be loaded before Jemm in CONFIG.SYS and FSHARE.EXE is a buggy DOS TSR. ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Freedos-user mailing list Freedos-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freedos-user
