From a9a943fbfe4e7e00d0d3aa42890d40383f198bb8 Mon Sep 17 00:00:00 2001
From: bicarus <202771338+bicarus-dev@users.noreply.github.com>
Date: Tue, 14 Jul 2026 17:06:00 -0700
Subject: [PATCH] jb: fix card not detected on title screen (#804)

## Link to GitHub Issue or related Pull Request, if one exists
n/a

## Description of change
Fix a long standing issue with card reader behavior in jubeat.

sciunit emulation has a bug - when on the title screen / demo loop,
inserting a card did not generate an interrupt. Users always had to
press the game start button and card in. Fix this by reversing what the
actual sciunit does and mirroring the state machine behavior.

## Testing
Tested L44 and K44.
---
 src/spice2x/misc/sciunit.cpp | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/src/spice2x/misc/sciunit.cpp b/src/spice2x/misc/sciunit.cpp
index 94b6fc5..c2bd3f9 100644
--- a/src/spice2x/misc/sciunit.cpp
+++ b/src/spice2x/misc/sciunit.cpp
@@ -20,6 +20,7 @@ static cardunit_card_cardnumber_t cardunit_card_cardnumber = nullptr;
 static HINSTANCE SCIUNIT_INSTANCE;
 static std::string SCIUNIT_INSTANCE_NAME = "sciunit.dll";
 static bool SCIUNIT_INITIALIZED = false;
+static int SCIUNIT_STATUS = 0;
 static bool CARD_IN = false;
 static bool CARD_PRESSED = false;
 static uint8_t CARD_UID[8];
@@ -150,11 +151,11 @@ static int __cdecl sciunit_finalize() {
 }
 
 static int __cdecl sciunit_get_errorunit() {
-    return 0;
+    return -1;
 }
 
 static int __cdecl sciunit_get_stat() {
-    return 0;
+    return SCIUNIT_STATUS;
 }
 
 static int __cdecl sciunit_get_version(int a1, int a2) {
@@ -163,6 +164,7 @@ static int __cdecl sciunit_get_version(int a1, int a2) {
 
 static int __cdecl sciunit_initialize() {
     SCIUNIT_INITIALIZED = true;
+    SCIUNIT_STATUS = 1;
     return 0;
 }
 
@@ -223,8 +225,12 @@ static int __cdecl sciunit_reset() {
 }
 
 static int __cdecl sciunit_update() {
-    if (SCIUNIT_INITIALIZED)
+    if (SCIUNIT_INITIALIZED) {
+        if (SCIUNIT_STATUS == 1) {
+            SCIUNIT_STATUS = 2;
+        }
         update_card();
+    }
     return 0;
 }