[no subject]

The problem is that the screen memory is not continous/contiguous. There are
gaps for the so-called "screen holes" which are 8 bytes of memory every so
often in the screen area which are not used for screen display but instead
are used as scratchpad areas by the slot firmware - the disk controller
firmware in particular!

The screen holes are at $478-F, $4F8-F, $578-F, ..., $7F8-F. (In decimal,
1144-1151, 1272-1279, etc)

ProDOS knows this memory is special and shouldn't be casually overwritten by
programs loading the entire screen memory area. DOS 3.3 offered no such
protection. People who tried this "trick" in DOS 3.3 will be familiar with
hearing the disk drive recalibrate when a screen image is reloaded. This is
due to the disk controller screen hole bytes being overwritten with
information from the saved screen instead of the current values that DOS was
expecting.
-- 
Peter Watson
-- Write to MSDOS disks on the Apple IIgs?
-- Impossible!  ;-)


"Bender MX" <no@morespam.com> wrote in message
news:TeUCb.69581$bC.14788@clgrps13...
> Hi All,
>
>   I was trying to 'Bsave' and 'Bload' lo-res / text screens
> under Prodos (emulator) tonight ...
>
> It's a No-Go - what gives?  Does Prodos not allow
> Bload filename,a1024  ???
>
> Any Help appreciated
>
> TIA,
> Craig
>
>