Example of doing KERNAL calls (using MCIOUT) and POINTER on Strings

[Xiphod]

Here are a couple BASLOAD examples to show the setup of doing KERNAL calls from BASIC, and how to pass along register settings to those calls.

Also shows using the POINTER keyword on a BASIC-string and passing that pointer into a KERNAL call.

KDEMO1 uses GOLDEN-RAM ($0400), populating that and then dumping the content to a file.

KDEMO2 uses the BANK region ($A000), similarly populating that and dumping to a file. Since this a higher address region, a little extra steps are needed to pass the HI/LO portions of the address.

KDEMO3 shows using MCIOUT to write out a full copy of all of VRAM (in a couple seconds), followed by another approach that copies VRAM to BANK RAM and then BSAVE back to disk (which is much slower, like >5 minutes to write the 128KB).


Intended as an introduction to the general concepts of interfacing with X16 KERNAL calls from BASIC (using the "memory-mapped" register proxies in the $03XX region used by KERNAL). For instructive/discussion purposes, not intended as the optimal (performance) approach. The general processing flow can be applied to other languages (of where to POKE/PEEK).

Note, seems to me that CHKOUT ($FFC9) isn't yet documented at the X16 Tech Ref page.

[Xiphod]

Updated to include example of using MCIOUT to interact with VRAM.