John,
Glad to hear it exists. The question I am trying to answer is about the
boilerplate. Looking through a few of the Traveling Software ROMs it would
appear that each one is slightly different. Is this because the interrupt
routines are different for various software used on the ROMs?
Kurt
On Thursday, June 11, 2015 9:03 AM, John R. Hogerhuis <jho...@pobox.com>
wrote:
On Thu, Jun 11, 2015 at 8:36 AM, Kurt McCullum <kurt.mccul...@att.net> wrote:
> Does this book still exist?
>
> "The Secrets of the Option ROM Revealed" by Mo Budlong
>
It exists at my house. Mo also wrote RBASIC.
The main takeaway though is the boilerplate assembly code which you
base an OptROM on, switching, and calls in/out of optrom to the main
ROM. The boilerplate code inlcudes the ROM portion of interrupt
handlers that need to be present since when the OptROM is switched in
since interrupts can happen any time. It also includes the
"installation" code.
Steve and I worked a bit on the "shell" and maybe the call code. If
anyone wants to write their own OptROM I think we can get you some
code.
-- John.
