Peritek VCD-V, User Manual

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Peritek
Programming On-board Devices and Memories 5-45
values are held in a temporary register inside the BT463 until the blue
value is entered.
BT463 registers include bit-mask (or read mask), allowing any
combination of R, G, B and overlay bit(s) to be unconditionally masked
off. Additonal registers include blink mask, allowing any of these same
bit(s) to be blinked. The details of the internal control registers are
documented in the BT463 data sheet.
Table 5-25 BT463 registers
VMEbus
Offset Mnemonic Function
3 ADRLO Low 8 bits of the address register.
Autoincrements after access to REGDBR or
PALET. (See description on previous page).
7 ADRHI High 4 bits of the address register.
Autoincrements after access to REGDBR or
PALET. (See description on previous page).
B REGDBR Data Buffer for control registers, window type
table, and cursor colors - 2 x 3 (R,G,B). R,G,B
locations cycled by mod-3 counter
F PALET Color map palette (R or W). Primary 256 x 3
(R,G,B) and overlay 15 x 3 (R,G,B). R,G,B
locations cycled by mod-3 counter.
Note
Window Type Table (WTT) must not be updated during active display.
Also, WTT must be programmed with multiple copies of cursor color.