] On Mon, 29 Mar 1999, Maarten ter Huurne wrote:
]
] > At 03:43 PM 3/29/99 +0200, you wrote:
] >
] > >> Besides, what kind of program would leave the mapper in a different state
] > >> than when it was started?
] > >
] > >I am busy on a muli-tasking system that cuts programs off on the
] > >interrupt. It is very well possible that one program sets the mappers is
] > >some state and when an other program is called, it's memory-status will be
] > >saved. Therefor I need a way to read all settings:slots, subslots and
] > >mappers.
] >
] > You don't have to _read_ them, you have to _know_ them!
] > It must be clear by now that remembering what you write to the mapper ports
] > is a reliable way of knowing the mapper settings, unlike reading the ports.
]
] Not at all reliable. I don't know what all programs do with it. If they
] are programmed correctly according to the rules I make for the operating
] system, it will be ok. But I designed it in a way that all currently
] existing programs that don't use the bios will probably work fine. And I
Why do you want all programs to work correctly under your os? Most programs
that access the mapper directly, without using either memman or the dos2
mapper support routines, are cracked megarom games. And those games will most
probably not run correctly under your os anyway, because of their resource
usage, etcetera.
I think that you should not worry too much about incompatible programs if you
make sure that your os works properly with memman and the dos2 mapper support
routines.
Besides, you can also build two drivers in your os. One which reads directly
from the mapper ports and one which uses backup-copies in your workarea. Then
you can give the os startup program an option, so that the user can decide
for him/herself what method your os should use (depending on the mapper types
in his/her system and things like that).
Just compare this to DOS2. When you use DOS2, you have the option to run the
program MAP.COM, which patches DOS2 to read directly from mapper ports. Ideal
to launch hacked megaromgames from harddisk.
Kind regards,
Alex Wulms
--
Alex Wulms/XelaSoft - MSX of anders NIX - Linux 4 ever
See my homepage for info on the *** XSA *** format
http://www.inter.nl.net/users/A.P.Wulms
****
MSX Mailinglist. To unsubscribe, send an email to [EMAIL PROTECTED] and put
in the body (not subject) "unsubscribe msx [EMAIL PROTECTED]" (without the
quotes :-) Problems? contact [EMAIL PROTECTED] (www.stack.nl/~wiebe/mailinglist/)
****
