Re: firmware for the PseudoDisk

[bieling@terra.es]

Alex Freed wote:

> > Do you mean "It's relatively easy to read fragmented files" ?
>
> Yes, it is. Consider the NIB image. At any given time before the "head"
> repositioning (that takes a while on the real hardware) we are only
> reading a single track. That is 13 blocks. Even if a cluster is one sector,
> we only need to store POINTERS to the 13 physical SD card blocks
> that hold this data. They don't need to be contiguous.

Great !

As thinking is free, both as in "free speech" and as in "free beer",
here are my thoughts about this :

boot sequence :

1.- Firmware : determine a valid fat16 sd card is pluged in. If it is
then goto 2, else goto 4.
2.- Firmware : Locate and "move to" the root-level folder called Apple2
: if found then goto 3, else goto 4.
3.- Firmware : locate a file called "customboot.a2", if found, load and
transfer control to it (more on boot.a2 later). else (If not found)
goto 4.
4.- Firmware : load and transfer from the firmware another, fixed,
firmwareboot.a2 code and transfer control to it.

The idea is:

1st. If you wanted to use an sd card in your apple2, it should be ok to
prepare it a little bit : create an Apple2 folder so that you and
everybody else knows what's the purpose of the files inside it. Also
allows you to keep disk images organized in groups. Ok, Alex, I know
you still don't like this idea very much, but keep reading on please.

2nd. Devise a method to customize the startup-sequence : the standard
firmware-based one (firmwareboot.a2) is executed when there's no
customboot.a2 inside the apple2 folder. Necesarily, the firmware
firmwareboot.a2 code won't/can't have all the desirable
functionalities. First, because it has to be designed, deployed and
debuged in a short period of time. 2nd because bright ideas may come in
later. 3rd because there might be code size limitations. 4th because
maybe it's not going to be possible to flash it easily later on into
the card's firmware.

About (firmware/custom)boot.a2 (desirable) functionality:

firmware version:
-Allows choosing the image to boot from (disk#1) and the images to
appear "online" as disk#2, #3, etc.
-This should preferably be a non-volatile, persistent setting between
power cycles of the computer (maybe read from a conf.file inside the
Apple2 folder ?).
-Also, in the event of a missing boot configuration, a default set of
images names could be predefined to boot from : for example, boot by
default from image whose name is s6d1, and put online s6d2 as disk#2,
etc.
-Also, if a menu pops up during the boot sequence, make it dissapear
and continue booting after a few seconds, or alternatively, ask the
user to press a key during boot in order to make the firmware utilities
menu program load and run. The idea here is that the computer has to be
able to boot/reboot without user interaction.
-This is one you'll like, Alex: Allow renaming the root level folders
:-)
-More. ? . (allow hot swapping the sd card ?)

Loadable "customboot.a2" version:
-All the firmware functionalities + other handy utilities that the time
will tell.
-Whatever, another completely different use: for example, a driver for
a fat16 filesystem custom Apple2 D.O.S. hehehe

What do you think ?

Regards,
Jorge.