Re: Apple IIe boot question

["Chuck Morris" <nospam@nospam.net>]

Bill Garber <willy46pa@comcast.net> wrote in message
mrCcnfewMsTd_GijXTWJhA@comcast.com">news:mrCcnfewMsTd_GijXTWJhA@comcast.com...
>

I'll take your last question first:  The Apple II+ (my first computer, btw)
already has an autostart rom installed.  This and the addition of Applesoft
Basic in rom instead of the Integer Basic found in the Apple II were the
most significant changes from the Apple II.  Without the autostart rom, the
II+ would never boot from a diskette automatically - you'd have to issue a
PR#6 from the keyboard instead.

As for the setup you described, with the 3.5" drives connected to slot 6,
the CFFA in slot 5 and the 5.25" drives in slot 4, the way the autostart
works ensures that direct booting can only occur from a 3.5" disk.  I
checked in my old copy of "Apple II Monitors Peeled" after my last post, and
the process doesn't know or care what drives are empty, which is why it
won't bypass an empty drive.  It simply scans all slots from 7 down to 1
until it finds a disk controller card.  When it does, it branches to the
disk controller card's rom code at $Cx00, where x is the slot number in
which it found the card.  The rom code will then attempt to boot from an
attached drive.

If the CFFA card is one that the autostart rom would recognize as a disk
controller card, and if the card has a rom that can boot from it, then it in
theory should work in any slot.  In practice however, whether it works or
not depends largely on whether the code in the rom is fully relocatable or
not.  Writing such code can require the code to be a bit longer than it
might otherwise be, and depending on how much functionality has been
squeezed into the rom code, there may not have been adequate room for both
the full functionality and relocatable code.  If this was the reason why the
CFFA card didn't work fully in any slot other than slot 5, then whoever
wrote the rom code presumably could produce a custom version of the same
code that was written with it's code targeted to $C700 instead of $C500, and
a CFFA card with this rom should then work in slot 7 just as your current
card works in slot 5.  If that is the source of the problem then the ideal
solution would be to try to rework the rom code for the CFFA card to make it
fully relocatable, at which point the card would work properly in all slots.
It would be the right approach though, and it would make the CFFA card an
even better product in the long run.