DIWHIGH

Address Name Description DFF1E4 DIWHIGH Display window upper bits for start, stop

Overview

This is an added register for Hires chips, and allows larger start
& stop ranges. If it is not written, (DIWSTRT, DIWSTOP)
description holds. If this register is written, direct start & stop
positions anywhere on the screen. It doesn't affect the UHRES
pointers.

Bit 15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00 0 0 H10 H1 H0 V10 V9 V8 0 0 H10 H1 H0 V10 V9 V8 (stop) (start)

H1 and H0 values define 70ns and 35ns increments respectively, and new LISA bits.

Note: In all 3 display window registers, horizontal bit positions have been renamed to reflect HIRES pixel increments, e.g. what used to be called H0 is now referred to as H2.

• DIWSTRT/DIWSTOP
• Hardware