Re: TransWarp GS

[mjmahon@aol.com (Michael J. Mahon)]

Bryan Parkoff asked:

>    I know that 65816 always starts at $FF/FFFC or $FF/FFEC for cold reboot.
>I understand that TransWarp GS has its own data or program that has
>approximately 32KB from $8000 to $FFFF in bank $BC.
>    In fact, 128KB ROM in both bank $FE and $FF are ALWAYS UNCHANGED while
>it uses bank $BC to display TransWarp GS name and audio before starting cold
>reboot.
>    I wonder how do 65816 cause to map to $BC/FFFC instead of $FF/FFFC while
>ROM is never modified by Applied Engineering.

I assume that the TransWarp GS has an on-board ROM.

Since the TransWarp board contains the processor, it gets to do whatever it
wants prior to giving control to the main board ROM.  This involves re-mapping
the 65816 address space during the board's initialization.

-michael

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