Yup, with the UMB driver, you can load DOS high, along with drivers and TSRs. Pretty cool on a resource-limited system. EMM386 or HIMEM not required.
Minor Correction
Loading DOS high is not possible with this arrangement since there is no "HIGH" memory, only UMB. If I understand correctly, "HIGH memory" is the segment immediatly
beyond 1 megabyte.
However, even with my setup, which incudes EGA and Hard Disk which both use portions of "Upper Memory", I am able to use one block of 128K of UMB. I can load dosdata, command.com, several device drivers, and TSR's in that 128K of UMB. My config.sys starts out as follows
device=c:\use!umbs\clearmem.sys d000 2000 (clearmem.sys Chuck(G)'s wonderful creation)
device=c:\use!umbs\use!umbs.sys
dos=umb
dosdata=umb
shell=c:\dos\command.com /h/e:512 c:\dos /p
devicehigh=c:\hotshot\fdd.sys
devicehigh=c:\dos\setver.exe
devicehigh=c:\dos\ega.sys
If I change the "dos=umb" to "dos=high,umb" most of the system kernal still loads in low memory, since there is no actual "HIGH" memory. However the "dosdata=umb" puts 17,800 bytes of the system kernal into UMB. And the "shell=command.com /h ..." puts all of command.com in UMB. Kind of inconsistent here, because one could interpret the /h as referring to "HIGH memory, but it actually refers to UMB, or "UPPER momory.
Check out the folowing
View attachment 7318 This is the current memory configuration for my 5155. Note that I have 608,960 bytes of base memory free and there is still 91,184 bytes of "UPPER" memory available for more drivers and tsr's.