VDC_MAWR = 0 ; Memory Address Write Register
VDC_MARR = 1 ; Memory Address Read Register
-VDC_VWR = 2 ; VRAM Write Register (write only)
-VDC_VRR = 2 ; VRAM Read Register (read only)
+VDC_VWR = 2 ; VRAM Write Register
+VDC_VRR = 2 ; VRAM Read Register
VDC_UNK03 = 3 ; (unknown)
VDC_UNK04 = 4 ; (unknown)
VDC_CR = 5 ; Control Register
; VDC port
; Note: The zero-page addressing mode is redirected to page $20.
-; Therefore, absolute addressing mode must be used when writing to this port.
-; We force it by using mirror locations that are outside of zero page.
+; We avoid it by using mirror locations that are outside of the zero page.
VDC_CTRL := $0200
VDC_DATA_LO := $0202
; HuC6260 -- Video Color Encoder (VCE)
; The DAC has a palette of 512 colours.
-; The bitmap of the palette data is this: 0000000gggrrrbbb.
+; The bitmap of that data is 0000000gggrrrbbb (Green, Red, Blue).
; You can read and write the DAC registers.
VCE := $0400 ; base
CDR_MEM_DISABLE := $1803
CDR_MEM_ENABLE := $1807
-; Write VDC register
-.macro VREG arg1,arg2
+; Write to a VDC register.
+.macro VREG arg1, arg2
st0 #arg1
st1 #<(arg2)
st2 #>(arg2)