From 5260f5f5cd8c1befe3600e348f154bf1280a149c Mon Sep 17 00:00:00 2001
From: TomW <TomW@localhost>
Date: Sat, 12 Sep 2015 14:57:14 +0100
Subject: [PATCH] PIC clears pending flag when acknowledging interrupt. PIT
 latch mode works correctly. Fixes 'High Performance PC' mode in Lemmings.

---
 src/pic.c |  1 +
 src/pit.c | 17 ++++++++++++++++-
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/src/pic.c b/src/pic.c
index 3dbf8c1..a73ad15 100644
--- a/src/pic.c
+++ b/src/pic.c
@@ -110,6 +110,7 @@ void pic_write(uint16_t addr, uint8_t val, void *priv)
                                         if (pic.ins&(1<<c))
                                         {
                                                 pic.ins&=~(1<<c);
+                                                pic.pend &= ~(1 << c);
                                                 pic_update_mask(&pic.mask2, pic.ins);
 
                                                 if (c == 2 && (pic2.pend&~pic2.mask)&~pic2.mask2)
diff --git a/src/pit.c b/src/pit.c
index e02523e..ffb8509 100644
--- a/src/pit.c
+++ b/src/pit.c
@@ -259,6 +259,21 @@ static void pit_over(int t)
         pit.running[t] = pit.enabled[t] && pit.using_timer[t];
 }
 
+int pit_get_timer_0()
+{
+        int read = (int)((pit.c[0] + ((1 << TIMER_SHIFT) - 1)) / PITCONST) >> TIMER_SHIFT;
+//pclog("pit_get_timer_0: t=%i using_timer=%i m=%i\n", 0, pit.using_timer[0], pit.m[0]);
+        if (pit.m[0] == 2)
+                read++;
+        if (read < 0)
+                read = 0;
+        if (read > 0x10000)
+                read = 0x10000;
+        if (pit.m[0] == 3)
+                read <<= 1;
+        return read;
+}
+        
 static int pit_read_timer(int t)
 {
         timer_clock();
@@ -333,7 +348,7 @@ void pit_write(uint16_t addr, uint8_t val, void *priv)
                                 pit.rm[val>>6]=3;
                                 pit.rl[t] = pit_read_timer(t);
                         }
-                        pit.rereadlatch[val>>6]=1;
+//                        pit.rereadlatch[val>>6]=1;
                         if ((val>>6)==2) ppispeakon=speakon=(pit.m[2]==0)?0:1;
                         pit.initial[t] = 1;
                         if (!pit.m[val >> 6])