diff --git a/HISTORY.txt b/HISTORY.txt
index 8821025..333f3b5 100644
--- a/HISTORY.txt
+++ b/HISTORY.txt
@@ -81,6 +81,7 @@ Genesis Plus GX 1.7.5 (xx/xx/xxxx) (Eke-Eke)
 * improved console region auto-detection for a few PAL-only games (The Smurfs Travel the World & Williams Arcade's Greatest Hits)
 * improved I2C EEPROM boards emulation accuracy
 * improved SVP memory handlers accuracy (fixes Virtua Racing debug mode)
+* improved accuracy of 68k access to Z80 bus delays
 * fixed Realtec mapper behavior on soft-reset and with TMSS hardware
 * fixed Game Genie / Pro Action Replay lock-on support when Mega CD hardware is enabled 
 * fixed Game Genie / Pro Action Replay lock-on support with games larger than 8MB
@@ -167,9 +168,9 @@ Genesis Plus GX 1.7.5 (xx/xx/xxxx) (Eke-Eke)
 * fixed Mode 1 rendering (TMS99xx "text" mode)
 * fixed Master System II extended video modes sprite parsing (fixes Mega Man 2 demo)
 * fixed Game Gear display rendering regression when left/right borders were disabled
-* fixed 68k cycles delay on invalid VRAM writes (fixes "Microcosm" intro loop)
 * fixed address/code potential corruption by one-instruction execution delay after HV interrupts activation (fixes Pugsy's Pyramids stage boss) 
 * optimized tile caching
+* reverted FIFO access timings hack when using invalid write code value
 
 [Core/Sound]
 ---------------
diff --git a/builds/genesis_plus_gx_libretro.dll b/builds/genesis_plus_gx_libretro.dll
index bbe3278..8284d8a 100644
Binary files a/builds/genesis_plus_gx_libretro.dll and b/builds/genesis_plus_gx_libretro.dll differ
diff --git a/builds/genplus_cube.dol b/builds/genplus_cube.dol
index f72b587..ffa1c57 100644
Binary files a/builds/genplus_cube.dol and b/builds/genplus_cube.dol differ
diff --git a/builds/genplus_wii.dol b/builds/genplus_wii.dol
index 58e8490..43275cc 100644
Binary files a/builds/genplus_wii.dol and b/builds/genplus_wii.dol differ
diff --git a/core/mem68k.c b/core/mem68k.c
index 81e9d80..2e302f5 100644
--- a/core/mem68k.c
+++ b/core/mem68k.c
@@ -140,6 +140,9 @@ unsigned int m68k_lockup_r_16 (unsigned int address)
 
 unsigned int z80_read_byte(unsigned int address)
 {
+  /* Z80 bus access latency */
+  m68k.cycles += 1 * 7;
+
   switch ((address >> 13) & 3)
   {
     case 2:   /* YM2612 */
@@ -172,6 +175,9 @@ unsigned int z80_read_word(unsigned int address)
 
 void z80_write_byte(unsigned int address, unsigned int data)
 {
+  /* Z80 bus access latency (fixes Pacman 2: New Adventures sound engine crashes & Puyo Puyo 2 crash when exiting option menu) */
+  m68k.cycles += 1 * 7;
+
   switch ((address >> 13) & 3)
   {
     case 2: /* YM2612 */
@@ -207,7 +213,6 @@ void z80_write_byte(unsigned int address, unsigned int data)
     default: /* ZRAM */
     {
       zram[address & 0x1FFF] = data;
-      m68k.cycles += 2 * 7; /* ZRAM access latency (fixes Pacman 2: New Adventures & Puyo Puyo 2) */
       return;
     }
   }