From 56631fac30a5f5e7c22284bcb7b1a856689d3322 Mon Sep 17 00:00:00 2001
From: TC1995 <mariogplayer90@gmail.com>
Date: Tue, 16 Jan 2024 19:03:54 +0100
Subject: [PATCH] More fixes to the RTG series:

1. Make the RTG VGA series work on XT's.
2. The RTG3105 is limited to up to 512K of memory, not 1M.
3. Fixed rowoffset in 8bpp mode used by the RTG3105.
---
 src/video/vid_rtg310x.c | 41 +++++++++++++++++++++++++++++++++++------
 1 file changed, 35 insertions(+), 6 deletions(-)

diff --git a/src/video/vid_rtg310x.c b/src/video/vid_rtg310x.c
index e84696a65..e82763d15 100644
--- a/src/video/vid_rtg310x.c
+++ b/src/video/vid_rtg310x.c
@@ -209,6 +209,8 @@ rtg_out(uint16_t addr, uint8_t val, void *priv)
 static void
 rtg_recalctimings(svga_t *svga)
 {
+    const rtg_t  *dev  = (rtg_t *) svga->priv;
+
     svga->ma_latch |= ((svga->crtc[0x19] & 0x10) << 16) | ((svga->crtc[0x19] & 0x40) << 17);
 
     svga->interlace = (svga->crtc[0x19] & 1);
@@ -280,7 +282,7 @@ rtg_recalctimings(svga_t *svga)
                     if (svga->crtc[0x19] & 2) {
                         if (svga->hdisp == 1280)
                             svga->hdisp >>= 1;
-                        else
+                        else if (dev->type == 2)
                             svga->rowoffset <<= 1;
 
                         svga->render = svga_render_8bpp_highres;
@@ -382,7 +384,34 @@ rtg3106_available(void)
     return rom_present(RTG_3106_BIOS_ROM_PATH);
 }
 
-static const device_config_t rtg_config[] = {
+static const device_config_t rtg3105_config[] = {
+  // clang-format off
+    {
+        .name = "memory",
+        .description = "Memory size",
+        .type = CONFIG_SELECTION,
+        .default_int = 512,
+        .selection = {
+            {
+                .description = "256 KB",
+                .value = 256
+            },
+            {
+                .description = "512 KB",
+                .value = 512
+            },
+            {
+                .description = ""
+            }
+        }
+    },
+    {
+        .type = CONFIG_END
+    }
+  // clang-format on
+};
+
+static const device_config_t rtg3106_config[] = {
   // clang-format off
     {
         .name = "memory",
@@ -416,7 +445,7 @@ static const device_config_t rtg_config[] = {
 const device_t realtek_rtg3105_device = {
     .name          = "Realtek RTG3105 (ISA)",
     .internal_name = "rtg3105",
-    .flags         = DEVICE_ISA | DEVICE_AT,
+    .flags         = DEVICE_ISA,
     .local         = 1,
     .init          = rtg_init,
     .close         = rtg_close,
@@ -424,13 +453,13 @@ const device_t realtek_rtg3105_device = {
     { .available = rtg3105_available },
     .speed_changed = rtg_speed_changed,
     .force_redraw  = rtg_force_redraw,
-    .config        = rtg_config
+    .config        = rtg3105_config
 };
 
 const device_t realtek_rtg3106_device = {
     .name          = "Realtek RTG3106 (ISA)",
     .internal_name = "rtg3106",
-    .flags         = DEVICE_ISA | DEVICE_AT,
+    .flags         = DEVICE_ISA,
     .local         = 2,
     .init          = rtg_init,
     .close         = rtg_close,
@@ -438,5 +467,5 @@ const device_t realtek_rtg3106_device = {
     { .available = rtg3106_available },
     .speed_changed = rtg_speed_changed,
     .force_redraw  = rtg_force_redraw,
-    .config        = rtg_config
+    .config        = rtg3106_config
 };