From 9e5bce35ec5c0329d82ce7b2a796349a420e4836 Mon Sep 17 00:00:00 2001 From: mgcaret Date: Sat, 11 Mar 2017 11:16:05 -0800 Subject: [PATCH] 5X: one byte patch to default to 1 MHz --- rom5x/README.md | 11 +++++++++++ rom5x/options/accel_reverse/B1_FDD5_accel_reverse.s | 8 ++++++++ 2 files changed, 19 insertions(+) create mode 100644 rom5x/options/accel_reverse/B1_FDD5_accel_reverse.s diff --git a/rom5x/README.md b/rom5x/README.md index 1b5d4b8..c1bd951 100644 --- a/rom5x/README.md +++ b/rom5x/README.md @@ -22,4 +22,15 @@ that we got there from BEEP1) and returns back to BEEP1. Then, in only 6 bytes I can create two entry points that load the value into A that we need for the reset or boot routines, and then jump to the above patch. +## Options + +The options directory contains one or more subdirectories with optional patches +that change the default behavior of the Apple IIc Plus. + +### Accelerator Reverse + +The accelerator reverse patch is a 1-byte patch that causes the IIc Plus to boot up +at the normal speed. + +Pressing at reset time will make the machine run at 4 MHz. diff --git a/rom5x/options/accel_reverse/B1_FDD5_accel_reverse.s b/rom5x/options/accel_reverse/B1_FDD5_accel_reverse.s new file mode 100644 index 0000000..153a997 --- /dev/null +++ b/rom5x/options/accel_reverse/B1_FDD5_accel_reverse.s @@ -0,0 +1,8 @@ +; this reverses the accelerator to always start off at 1MHz +; at reset then selects 4 MHz +; This is useful if you spend more time at 1 MHz, for games + +.text +* = $fdd5 + .byte $f0 +