From 0646770d41dbee0819d225ef48dfb6206d86d3d3 Mon Sep 17 00:00:00 2001 From: Luca Ridarelli Date: Mon, 16 Jan 2017 20:27:01 +0100 Subject: [PATCH] Readme Update --- README.me | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/README.me b/README.me index 3308b78..9f8629c 100644 --- a/README.me +++ b/README.me @@ -3,12 +3,12 @@ APPLE ][ Stellation Two "The Mill" 6809 OS/9 daughter-board PCB and Prom code. DESCRIPTION This project contains schematics and software of a plug-in daughter-board for the APPLE ][ Stellation Two "The Mill" 6809 OS/9 card. -The daughter-board remaps Apple II ram as seen by the 6909 board to allows execution of Microware OS/9 . +The daughter-board remaps Apple II ram as seen by the 6909 board to allow execution of Microware OS/9 . This is not the original implementation of the Stellation Two daughter-board nor a clone of it. The original daughter-board made use of one 74S288 prom and 74LS367 Hex Buffer to create a custom memory mapping. -The high cost of 74S288 prom burners and scarce availability of 74S288 proms suggested to implement a different solution. +The high cost of 74S288 prom burners and the scarce availability of 74S288 proms suggested to implement a different solution. Then one ATmel ATF16V8C PLD has been programmed to emulate a prom with the right ram memory mapping combination. A switch has been added to allow for normal/OS9 memory mapping selection.