Mnbios not use fixed address, use dinamic structures storaging... for that
exists the structures.... Anyway the aplications not need fill the
structures....only need got a pointer to that structure... and the
aplications can get that asking to the kernel.
So I don't see much speed difference between UZIX and MNIOS in this
point... Both approachs have the same overhead... And, of course, since
48+48=96>64 you can't map an application and kernel together in the
same Z80 address space, so you have to swap to kernel mode and
application mode. This swap is the performance killer of both OSs.
That is not true, the BGP are disabled becuase i need create a list of the
allowed or forbidden... and that will come at the end.
Why creating such list? The permission of creating a process should not be
controlled by process scheduler...
So I think it would better implementing sleeping/suspended processes, not
killing the main reason to call an OS 'multitask', and not
'task-switcher'.
for call a OS "multitask" not need background process.
There is a concepts confusion here. The 'foreground' process(es) is(are) the
one(s) who
actually receive(s) data from input devices controlled by the user. The
'background'
processe(s) is(are) the one(s) who are running, but do not actually receive(s)
data
from input devices. Background and foreground processes can output data to
anywhere,
even to current user display.
So, calling a OS 'multitask' requires that this OS can run more then one
application at
once (in the user point of view for single-CPU machines). If an OS can run many
applications at once, but they do not run concurrently and the user can just
select
the active one, this is not a multitask OS, it's a task-switched OS.
NOT! that one only in 32KB of code!!!.... and you delete some lines... some
ones of that are included in that 32KB.
32KB kernel
16KB User Interface "MSXCOMMAND.EXEC"
16KB variable and structures space (for main CPU).
Hum... That confirms kernel/user mode swapping. Ok.
Anyway, just 32KB of code for 240+ functions... Wow... That's an average of
136 bytes per function... Microsoft/ASCII should be the worst Z80 coder in the
world when they created MSX2 BIOS, because they needed 48KB for the BIOS
(that surely doesn't have 240+ functions), plus 16KB for a simple CP/M code
and disk driver...
Regards,
Adriano
