OmniBook 300/425 - Freeing up conventional memory

[matthiaspaul]

(12-31-2016 12:58 PM)Dave Britten Wrote:  I do see behavior differences between my 200LX and OB300, though. On the 200LX, I can't alt-tab away from EDIT for some reason

Obviously, I can only guess without having a deeper look, but if this happens also with other programs of the "QBASIC family" like QBASIC or HELP and not with other programs, it might have to do with the non-standard way these programs interact with the keyboard. (EDIT.COM and HELP.COM are sort of "dummies" which internally call QBASIC.EXE with undocumented special parameters /EDCOM and /QHELP, respectively.) I remember that when I was developing an advanced DOS keyboard driver it took a lot of effort to make some of its special features work under QBASIC as well and keep it from temporarily loading its own embedded keyboard driver (INT 16h/AH=55h). However, this would not directly explain differences in the behaviour on the 200LX and the OB300, but could be the result of loaded drivers.

Quote:whenever I switch back to DOSSHELL, it redoes its disk inventory as though it's been freshly launched. All settings are the same as far as I can tell.

This might be an artifact of either the amount of available DOS memory or which pieces of memory got overwritten during swapping (IIRC DOSSHELL had two disk login modes selected depending on memory, recursively reading in the whole drive or only the current directory).

Greetings,

Matthias