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


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

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.

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.

This material is most likely derived from the official Amiga documentation and where applicable copyright remains with the original author.