Sunday, July 30, 2017

Revamping Hypervisor boot display, and SPACE to enter utility menu

Now that I have a much easier way to develop the boot ROM for the MEGA65 via the monitor_load command (which I have now pushed up from 230,400bps to 2,000,000bps as I previously discussed), I got inspired to fix the boot display of the MEGA65.

Basically in the past we had a 64x64 area for a 256-colour logo.  This predated the renaming to the MEGA65, and the creation of the wide MEGA65 banner.  As a result the banner was all squished into a tiny space and was almost unreadable and quite ugly.

I'd been meaning for a while to rework the boot ROM  to support a 320 pixel wide banner instead, so that the MEGA65 logo could be properly displayed.   So this is what I have done. I have also gone a step further, and included the MEGA65 logo as preinitialised data in RAM, so that it still shows up, even if you don't have an SD card inserted. 

In the process, because it is now so quick and easy to test new versions of the boot ROM, I also added the option to hold SPACE to enter the utility menu, which serves a similar role to the BIOS menu on old PCs, but will have different utilities.  The main utility planned for now is a combined FDISK+FORMAT utility, to make it easier to setup a new SD card for use in the MEGA65.  The utilities are also stored in pre-initialised memory (in this case the upper 30KB of the 32KB colour RAM), so that you don't need an SD card or anything else for them to be there. 

We have the bulk of the FDISK+FORMAT  utility already written, but need to work out how to get CC65 compiled programs to run on the MEGA65 when there is no C64 ROM yet loaded.

But for now, here is a screen shot of the revamped boot display, looking, I think, much nicer:


Hope you enjoy it.

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