From 74e2437d9198fa6a1a0256ebe41340d59105f533 Mon Sep 17 00:00:00 2001
From: OBattler <oubattler@gmail.com>
Date: Mon, 6 Nov 2023 07:05:15 +0100
Subject: [PATCH] 808x machines with >= 8 MHz CPU speed now default to fast
 PIT, fixes #3776.

---
 src/machine/machine.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/machine/machine.c b/src/machine/machine.c
index a21d8115c..c4ace6b4f 100644
--- a/src/machine/machine.c
+++ b/src/machine/machine.c
@@ -168,13 +168,15 @@ pit_irq0_timer(int new_out, int old_out)
 void
 machine_common_init(UNUSED(const machine_t *model))
 {
+    uint8_t cpu_requires_fast_pit = is486 || (is8086 && (cpu_s->rspeed >= 8000000));
+
     /* System devices first. */
     pic_init();
     dma_init();
 
     int pit_type = IS_AT(machine) ? PIT_8254 : PIT_8253;
     /* Select fast PIT if needed */
-    if (((pit_mode == -1) && is486) || (pit_mode == 1))
+    if (((pit_mode == -1) && cpu_requires_fast_pit) || (pit_mode == 1))
         pit_type += 2;
 
     pit_common_init(pit_type, pit_irq0_timer, NULL);