Re: A new boot code for Alex Freed's Pseudodisk ][...

[Alex Freed <alex_news@mirrow.com>]

Deckard wrote:
> is available here:
>
> http://boutillon.free.fr/Underground/Outils/Beautiful_Boot_PD8/Beautiful_Boot_PD8.html
>
> JM

C'est magnifique!

That's what I was hoping for - somebody writing better software.
I think I need to explain how the boot code is loaded in the latest 
revision of PD8.

The AVR microcontroller initializes the MMC/SD card and reads the sector 
following the boot sector - absolute sector 1. The firmware checks that 
the first byte is 1 and if so, 512 bytes are loaded into a buffer that 
the 6502 code (in PROM) will copy to $800 and run at $801.
If the first byte is NOT 1, then alternative default boot program will 
be used that lives inside the AVR's flash memory.

The first stage loaded appears to start with 6 rather than 1, so if you 
have a relatively new PD8, this won't work without a change in either 
the AVR firmware or the first byte but then the NB_BLK needs to be moved 
elsewhere.

-Alex.