From 16a5e4eb9e17417494d8d633340b5f241a11e293 Mon Sep 17 00:00:00 2001
From: angelosa <lordkale4@gmail.com>
Date: Fri, 18 Oct 2024 21:54:08 +0200
Subject: video/upd7220.cpp: ignore parameters beyond first one for pitch
 command * fix pc9801:burai intro MAME crash

---
 src/devices/video/upd7220.cpp | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/devices/video/upd7220.cpp b/src/devices/video/upd7220.cpp
index 8bb8a9e8238..e20c6ce920c 100644
--- a/src/devices/video/upd7220.cpp
+++ b/src/devices/video/upd7220.cpp
@@ -1376,10 +1376,20 @@ void upd7220_device::process_fifo()
 		break;
 
 	case COMMAND_PITCH: /* pitch specification */
-		if (flag == FIFO_PARAMETER)
+		// pc9801:burai writes a spurious extra value during intro, effectively ignored
+		// (only first value matters)
+		if (flag == FIFO_PARAMETER && m_param_ptr == 2)
 		{
 			m_pitch = (m_pitch & 0x100) | data;
 
+			if (m_pitch < 2)
+			{
+				// TODO: a pitch of zero will lead to a MAME crash in draw_graphics_line
+				// Coerce a fail-safe minimum, what should really happen is to be verified ...
+				popmessage("%s pitch == 0!", this->tag());
+				m_pitch = 2;
+			}
+
 			LOG("uPD7220 PITCH: %u\n", m_pitch);
 		}
 		break;
-- 
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