From 3758124cb84dab8d982b4107390f309fefdbf0f9 Mon Sep 17 00:00:00 2001
From: kub <derkub@gmail.com>
Date: Mon, 4 Oct 2021 18:03:49 +0200
Subject: [PATCH] sms vdp, support 224/240 line mode

---
 pico/mode4.c | 19 +++++++++++++------
 pico/sms.c   |  2 ++
 2 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/pico/mode4.c b/pico/mode4.c
index 6711febe..7f457c10 100644
--- a/pico/mode4.c
+++ b/pico/mode4.c
@@ -232,12 +232,14 @@ static void DrawDisplayM4(int scanline)
 
   // Find the line in the name table
   line = pv->reg[9] + scanline; // vscroll + scanline
-  if (line >= 224)
-    line -= 224;
+  line &= 0xff;
 
   // Find name table:
   nametab = PicoMem.vram;
-  nametab += (pv->reg[2] & 0x0e) << (10-1);
+  if ((Pico.video.reg[0] & 6) == 6 && (Pico.video.reg[1] & 0x18))
+    nametab += ((pv->reg[2] & 0x0c) << (10-1)) + (0x700 >> 1);
+  else
+    nametab += (pv->reg[2] & 0x0e) << (10-1);
   nametab += (line>>3) << (6-1);
 
   dx = pv->reg[8]; // hscroll
@@ -276,7 +278,7 @@ static void DrawDisplayM4(int scanline)
 static void FinalizeLineRGB555M4(int line);
 void PicoFrameStartMode4(void)
 {
-  int lines = 192, coffs;
+  int lines = 192, columns = 256, coffs;
   skip_next_line = 0;
   screen_offset = 24;
   Pico.est.rendstatus = PDRAW_32_COLS;
@@ -291,13 +293,18 @@ void PicoFrameStartMode4(void)
       lines = 224;
     }
   }
-  line_offset = PicoIn.opt & (POPT_DIS_32C_BORDER|POPT_EN_SOFTSCALE) ? 0 : 32;
+  if (PicoIn.opt & POPT_EN_SOFTSCALE) {
+    line_offset = 0;
+    columns = 320;
+  } else
+    line_offset = PicoIn.opt & POPT_DIS_32C_BORDER ? 0 : 32;
+
   coffs = line_offset;
   if (FinalizeLineM4 == FinalizeLineRGB555M4)
     line_offset = 0 /* done in FinalizeLine */;
 
   if (Pico.est.rendstatus != rendstatus_old || lines != rendlines) {
-    emu_video_mode_change(screen_offset, lines, coffs, 256);
+    emu_video_mode_change(screen_offset, lines, coffs, columns);
     rendstatus_old = Pico.est.rendstatus;
     rendlines = lines;
   }
diff --git a/pico/sms.c b/pico/sms.c
index 6fff9e7a..5e4b8766 100644
--- a/pico/sms.c
+++ b/pico/sms.c
@@ -380,6 +380,8 @@ void PicoFrameMS(void)
     z80_nmi();
   Pico.ms.nmi_state = nmi;
 
+  if ((Pico.video.reg[0] & 6) == 6 && (Pico.video.reg[1] & 0x18))
+    lines_vis = (Pico.video.reg[1] & 0x08) ? 240 : 224;
   PicoFrameStartMode4();
   hint = pv->reg[0x0a];
 
-- 
2.39.2