MEGA65: ROWMASK function of RRB is not implemented

[mgkaiser]

Describe the bug
The ROWMASK function described in the "Bit Fields when GOTOX bit is set" section of "Displaying more than 256 unique characters via ”Super-Extended Attribute Mode”" does not appear to be implemented

Used version of the project
WINDOWS: console is open
INFO: DMA chip current revision: 1 (F018 rev-B, new)
ROM version detected: 920377 Closed-ROMs (installed,external)
ROM SHA1: 573e8be11f5641d4a8293a8aa0c17b3b3c5d16f0 (intact)
Last RESET type: XEMU-STARTUP
Hyppo version: master,20220117.14,f7554a8 (built-in)
HDOS virtualization: OFF, root = C:\Users\mgkai\AppData\Roaming\xemu-lgb\mega65\hdos
Disk8 = C:\Users\mgkai\AppData\Roaming\xemu-lgb\mega65\hdos\mega65.d81
Disk9 =
C64 'CPU' I/O port (low 3 bits): DDR=7 OUT=7
Current PC: $E1B3 (linear: $003E1B3)
Current VIC and I/O mode: VIC4 PAL, hot registers are enabled

Xemu host CPU usage so far: avg=185.58%, min=44%, max=18736% (860 counts), uptime=00:30
Xemu's host OS: Windows WINDOWS10-SCHOO 6.2 x86_64

To Reproduce

1. Run "EXTCHAR" on the attached disk image. More readable source is in "EXTCHAR.EL" on same disk image
2. Press "N" or "M" on the keyboard

Expected behavior
At any given moment only one raster line of the rewritten character should be visible and should change as "N" or "M" are pressed since pressing "N" and "M" are changing the value in byte 1 of color ram on a character a character for which "GOTOX" is set. You can further prove that "GOTOX" is set for the character by pressing "S" and "D" to observe it moving left and right by a single pixel.

Screenshots

Computer/Device (please complete the following information):

Additional context
D81 Disk image with files mentioned in steps to reproduce

ELEVEN.zip

[hernandp]

Can I take this one @lgblgblgb ?

[lgblgblgb]

@hernandp Who am I to push you back? ;) Seriously now: of course. Thank you!!

[lgblgblgb]

MEGA65/mega65-core#340

I believe this is the one in MEGA65-core. Just commenting some issues now to have some kind of link to the MEGA65-core material.

Test program: https://github.com/MEGA65/mega65-tools/blob/master/src/tests/test_340.c

PR on vic4test to test this feature: smnjameson/vic4tests#3

[lgblgblgb]

I consider this finished, at least no other feedback yet, and all mentioned cases/tests seem to be OK with the patch.