From 63e49696b8fdc02ca1a5c079f00045a950c072d4 Mon Sep 17 00:00:00 2001
From: Will Scullin <scullin@scullin.com>
Date: Mon, 8 Mar 2021 19:28:52 -0800
Subject: [PATCH] Goose slot detection code

---
 js/apple2io.ts | 4 +++-
 js/mmu.ts      | 8 ++++++++
 js/util.ts     | 2 +-
 3 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/js/apple2io.ts b/js/apple2io.ts
index c9b127f..551e8fb 100644
--- a/js/apple2io.ts
+++ b/js/apple2io.ts
@@ -11,7 +11,7 @@
 
 import CPU6502 from './cpu6502';
 import { Card, Memory, MemoryPages, TapeData, byte, Restorable } from './types';
-import { debug } from './util';
+import { debug, garbage } from './util';
 
 type slot = 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7;
 type button = 0 | 1 | 2;
@@ -364,6 +364,8 @@ export default class Apple2IO implements MemoryPages, Restorable<Apple2IOState>
                 }
                 if (card) {
                     result = card.read(page, off);
+                } else {
+                    result = garbage();
                 }
                 break;
             default:
diff --git a/js/mmu.ts b/js/mmu.ts
index 631199a..94fc665 100644
--- a/js/mmu.ts
+++ b/js/mmu.ts
@@ -392,17 +392,25 @@ export default class MMU implements Memory, Restorable<MMUState> {
         if (this._intcxrom) {
             for (let idx = 0xc1; idx < 0xd0; idx++) {
                 this._readPages[idx] = this._pages[idx][1];
+                this._writePages[idx] = this._pages[idx][1];
+            }
+            if (this._slot3rom) {
+                this._readPages[0xc3] = this._pages[0xc3][0];
+                this._writePages[0xc3] = this._pages[0xc3][0];
             }
         } else {
             for (let idx = 0xc1; idx < 0xd0; idx++) {
                 this._readPages[idx] = this._pages[idx][0];
+                this._writePages[idx] = this._pages[idx][0];
             }
             if (!this._slot3rom) {
                 this._readPages[0xc3] = this._pages[0xc3][1];
+                this._writePages[0xc3] = this._pages[0xc3][1];
             }
             if (this._intc8rom) {
                 for (let idx = 0xc8; idx < 0xd0; idx++) {
                     this._readPages[idx] = this._pages[idx][1];
+                    this._writePages[idx] = this._pages[idx][1];
                 }
             }
         }
diff --git a/js/util.ts b/js/util.ts
index b3213eb..ffb3f83 100644
--- a/js/util.ts
+++ b/js/util.ts
@@ -17,7 +17,7 @@ const hex_digits = '0123456789ABCDEF';
 const bin_digits = '01';
 
 /** Returns a random byte. */
-function garbage(): byte {
+export function garbage(): byte {
     return (Math.random() * 0x100) & 0xff;
 }