From 67b6897fd0b12e0eb472709a6a0ec1ee0a502992 Mon Sep 17 00:00:00 2001 From: Oliver Schmidt Date: Sat, 11 Jan 2020 13:35:34 +0100 Subject: [PATCH] Allow start with active 80-column display. With active 80-column display there's no way to activate hires page2. Instead of directly fiddling with 80COLSTORE it seems the cleanest way to disable the 80-column display via the official firmware entry point. The ProDOS 8 Technical Reference Manual states in chapter 5.3.1.3 - 80-Column Text Card: ----- 80-column text cards -- and other Apple IIe features -- can be turned off using the following sequence of instructions: LDA #$15 ;Character that turns off video firmware JSR $C300 ;Print it to the video firmware ----- --- src/apple2.loader/loader.s | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/src/apple2.loader/loader.s b/src/apple2.loader/loader.s index fa4b705..22d7946 100644 --- a/src/apple2.loader/loader.s +++ b/src/apple2.loader/loader.s @@ -111,8 +111,15 @@ PRESS_ANY_KEY: sta READ_REF sta CLOSE_REF + ; Turn off 80-column firmware + lda VERSION + cmp #$06 ; //e ? + bne :+ + lda #$15 + jsr $C300 + ; Switch to hires page 2 - bit TXTCLR +: bit TXTCLR bit MIXCLR bit HISCR bit HIRES