I think the techniques are the same, but the actual routines will differ. The improved boiler plate John and I did is just an example. Steve
On Thursday, June 11, 2015, Kurt McCullum <kurt.mccul...@att.net> wrote: > 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. > > >
