Document 1605 DESQVIEW Description: DesqView is a multi-tasking DOS based program that relies on very specific uses of system memory. Specifically, it accomplishes its multi-tasking by bank-switching applications in and out of conventional memory (much like Concurrent DOS XM) and can use XMS UMB's (Upper memory blocks) and the HMA (High Memory Area) for storing its own program code and data. For maximum performance of DesqView under DRDOS 6.0, one should use QEMM386.SYS instead of EMM386.SYS and one should make sure that nothing from DRDOS is taking control of the A20 line (that is, using the HMA.) QEMM386.SYS should be used instead of EMM386.SYS, because the LIM driver which is a part of QEMM386.SYS has been enhanced for DesqView multi-tasking in conventional memory. HIDOS.SYS can be used along with QEMM386.SYS (as with DRDOS 5.0) to relocate the operating system, but, unlike DRDOS 5.0, it takes more work than just using the /BDOS=AUTO switch to keep DRDOS 6.0 out of the HMA. To keep DRDOS 6.0 out of the HMA for DesqView: 1) Make sure that the /MH option is not used on any of the DRDOS 6.0 commands that support it. This includes SHELL and SHARE. 2) Make sure that the HIBUFFERS command is not used in the CONFIG.SYS file. This command will use the HMA even if the Kernel is not put there with /BDOS=FFFF. 3) Make sure that the /BDOS option reads: /BDOS=AUTO. (NOTE: If one is unsure if the HMA is being allocated to DRDOS 6.0 instead of DesqView, one can use MEM /F before starting DesqView. This command will display an empty box if DRDOS 6.0 is not using the HMA.) Example: Here is an example CONFIG.SYS that will work properly with DesqView: SHELL=C:\DRDOS\COMMAND.COM C:\DRDOS6 /P /MU /E:512 BREAK=ON BUFFERS=5 FILES=30 LASTDRIVE=M HISTORY=ON, 256, ON, OFF, OFF DEVICE=C:\QEMM60\QEMM386.SYS R:2 NOVIDEOFILL RAM ROM ST: FXST=F000 DEVICE=C:\DRDOS\HIDOS.SYS /B=AUTO DEVICE=C:\QEMM60\LOADHI.SYS /R:3 C:\DRDOS\PCKWIN.SYS DEVICE=C:\QEMM60\LOADHI.SYS /R:1 C:\MOUSE\MOUSE.SYS DEVICE=C:\SSTORDRV.SYS HIDOS=ON