From cc385b7d9850708711bf899b0379a1fa1b5307c5 Mon Sep 17 00:00:00 2001
From: Steven Hugg <hugg@fasterlight.com>
Date: Sun, 16 Jul 2023 21:43:10 -0500
Subject: [PATCH] atari7800: fixed write mode

---
 src/machine/atari7800.ts | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/machine/atari7800.ts b/src/machine/atari7800.ts
index e0ca600e..ec61f81c 100644
--- a/src/machine/atari7800.ts
+++ b/src/machine/atari7800.ts
@@ -114,6 +114,7 @@ class MARIA {
   dli : boolean = false;
   h16 : boolean = false;
   h8 : boolean = false;
+  writemode : number = 0;
   indirect : boolean = false;
   pixels = new Uint8Array(320);
   WSYNC : number = 0;
@@ -140,6 +141,7 @@ class MARIA {
       h16: this.h16,
       h8: this.h8,
       indirect: this.indirect,
+      writemode: this.writemode,
     };
   }
   loadState(s) {
@@ -152,6 +154,7 @@ class MARIA {
     this.h16 = !!s.h16;
     this.h8 = !!s.h8;
     this.indirect = !!s.indirect;
+    this.writemode = s.writemode|0;
   }
   isDMAEnabled() {
     return (this.regs[0x1c] & 0x60) == 0x40;
@@ -225,7 +228,6 @@ class MARIA {
         let b2 = bus.read(dlhi + ((dlofs+2) & 0x1ff));
         let b3 = bus.read(dlhi + ((dlofs+3) & 0x1ff));
         let indirect = false;
-        const writemode = b1 & 0x80;
         // extended header?
         if ((b1 & 31) == 0) {
           var pal = b3 >> 5;
@@ -234,6 +236,7 @@ class MARIA {
           indirect = (b1 & 0x20) != 0;
           dlofs += 5;
           this.cycles += 10;
+          this.writemode = b1 & 0x80;
         } else {
           // direct mode
           var xpos = b3;
@@ -247,7 +250,7 @@ class MARIA {
         xpos *= 2;
         const ctrlreg = this.regs[0x1c];
         // gfx mode (readmode + writemode * 4)
-        const grmode = (ctrlreg & 0x3) + (writemode ? 4 : 0);
+        const grmode = (ctrlreg & 0x3) + (this.writemode ? 4 : 0);
         // kangaroo mode
         const kangaroo = (ctrlreg & 0x4) != 0;
         // double bytes?
@@ -687,12 +690,14 @@ export class Atari7800 extends BasicMachine implements RasterFrameBased {
       // extended header?
       let indirect = false;
       let description = "";
+      let writemode;
       const grmode = (ctrlreg & 0x3) + ((b1 & 0x80) ? 4 : 0);
       if ((b1 & 31) == 0) {
         var pal = b3 >> 5;
         var width = 32 - (b3 & 31);
         var xpos = this.readConst(dlhi + ((dlofs+4) & 0x1ff));
         indirect = (b1 & 0x20) != 0;
+        writemode = b1 & 0x80;
         dlofs += 5;
       } else {
         // direct mode
@@ -702,6 +707,7 @@ export class Atari7800 extends BasicMachine implements RasterFrameBased {
         dlofs += 4;
       }
       description += "X=" + xpos + " W=" + width + " P=" + pal;
+      if (writemode) description += " WM=1";
       if (indirect) description += " CHR=$" + hex((this.maria.regs[0x14] + this.maria.offset) & 0xff) + "xx";
       let gfxadr = b0 + (((b2 + (indirect?0:this.maria.offset)) & 0xff) << 8);
       description = " $" + hex(gfxadr,4) + " " + description;