Re: Question about UMBs

PC> So, I have (in pure DOS mode on this machine)
PC> an extra 144KB of memory, but I don't know how to inform DOS about
it....

>     You can't, DOS itself gather this info from XMS services if it
> instructed by DOS=UMB statement in config.sys.

you can't inform DOS, but DOS will ask you (through function XMS-10)
to give it all its UMB's (if and only if DOS=UMB).

so you have to install some few bytes, which must remain resident, until
DOS
got all the information - and the UMB's.
see EMM386.ASM (search for UMBsegments), how this can be implemented in a
few
bytes.
unfortunately, you can't uninstall the driver the any more, so these few
bytes will remain resident forever.

tom