added Scroll

This commit is contained in:
Charles Mangin 2018-08-08 16:58:34 -04:00 committed by GitHub
parent 7a4abdb627
commit f04d37ca84
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 4 additions and 0 deletions

View File

@ -2,3 +2,7 @@
A mixed display mode demo for the Apple IIe, written in 6502 Assembly
Uses $C019 on the IIe to detect the VBL interval and some cycle counting to switch display modes during the screen draw for a mix of low-res and text modes.
# Scroll
I had some fun working out how quickly to scroll low res text and keep it legible. Each row of text scrolls 1 pixel left when the one above it has scrolled all the way across the screen. The top scrolls as fast as I could manage, and the bottom one, well, it will eventually.