diff --git a/A2Mac/HiRes.swift b/A2Mac/HiRes.swift
index 83dcb66..c52cc4c 100644
--- a/A2Mac/HiRes.swift
+++ b/A2Mac/HiRes.swift
@@ -25,9 +25,9 @@ class HiRes: NSView {
     static let blockWidth = PixelWidth / blockCols
     static let blockHeight = PixelHeight / blockRows
 
-    let HiResBuffer1 = UnsafeRawBufferPointer(start: RAM + Page1Addr, count: PageSize * 2)
-    let HiResBuffer2 = UnsafeRawBufferPointer(start: RAM + Page2Addr, count: PageSize * 2)
-    var HiResBufferPointer = UnsafeRawBufferPointer(start: RAM + Page1Addr, count: PageSize * 2)
+    let HiResBuffer1 = UnsafeRawBufferPointer(start: MEM + Page1Addr, count: PageSize * 2)
+    let HiResBuffer2 = UnsafeRawBufferPointer(start: MEM + Page2Addr, count: PageSize * 2)
+    var HiResBufferPointer = UnsafeRawBufferPointer(start: MEM + Page1Addr, count: PageSize * 2)
     
     let HiResRawPointer = UnsafeRawPointer(RAM + Page1Addr)
 
diff --git a/A2Mac/ViewController.swift b/A2Mac/ViewController.swift
index ecdd8cf..d22b5e3 100644
--- a/A2Mac/ViewController.swift
+++ b/A2Mac/ViewController.swift
@@ -382,9 +382,11 @@ class ViewController: NSViewController  {
     var halted = true;
     
     func Update() {
-        clk_6502_per_frm_max = 0
+//        clk_6502_per_frm_max = 0
         
         clkCounter += Double(clkfrm)
+        // we start a new frame from here, so CPU is running even while rendering
+        clkfrm = 0
 
         frameCounter += 1
         
diff --git a/src/cpu/6502.c b/src/cpu/6502.c
index 6574ff0..1e0430f 100644
--- a/src/cpu/6502.c
+++ b/src/cpu/6502.c
@@ -713,7 +713,8 @@ void m6502_Run() {
 #ifdef SPEEDTEST
     for ( inst_cnt = 0; inst_cnt < iterations ; inst_cnt++ )
 #elif defined( CLK_WAIT )
-        for ( clkfrm = 0; clkfrm < clk_6502_per_frm_max ; clkfrm += clk )
+        // we clear the clkfrm from ViewController Update()
+        for ( ; clkfrm < clk_6502_per_frm_max ; clkfrm += clk )
 #else
 //    for ( ; m6502.pc ; )
     for ( ; ; )
diff --git a/src/cpu/instructions/6502_instr_load_store.h b/src/cpu/instructions/6502_instr_load_store.h
index 9eb8a0c..aa4bff2 100644
--- a/src/cpu/instructions/6502_instr_load_store.h
+++ b/src/cpu/instructions/6502_instr_load_store.h
@@ -92,15 +92,7 @@ char * charConv =
 **/
 INLINE void STR( uint16_t addr, uint8_t src ) {
     dbgPrintf("STR [%04X], %02X ", addr, src );
-
-    // I/O or ROM or RAM EXP
-    if ( ( addr >= 0xC000 ) && ( addr < 0xC100 ) ) {
-        return ioWrite( addr, src );
-    }
-    
-    // DO NOT MAKE IT NICER! faster this way!
-    *(RAM_PG_WR_TBL[ addr >> 8 ] + (addr & 0xFF)) = src;
-//    RAM[addr] = src;
+    memwrite(addr, src);
 }
 
 /**
diff --git a/src/dev/disk/disk.c b/src/dev/disk/disk.c
index b6c3888..e1fad51 100644
--- a/src/dev/disk/disk.c
+++ b/src/dev/disk/disk.c
@@ -17,7 +17,7 @@ disk_t disk = {
     0,              // clk_since_last_read
 };
 
-const int diskAccelerator_frames  = 5;
+const int diskAccelerator_frames  = 3;
 int diskAccelerator_count = 10;
 int diskAccelerator_speed = 25; // less than actual CPU speed means no acceleration
 //const unsigned long long clk_6502_per_frm_diskAccelerator = 25 * M / fps; // disk acceleration bumps up CPU clock to 25 MHz
diff --git a/src/dev/mem/mmio.h b/src/dev/mem/mmio.h
index 00ff13d..1b2bc28 100644
--- a/src/dev/mem/mmio.h
+++ b/src/dev/mem/mmio.h
@@ -28,7 +28,7 @@ videoMode_t videoMode = { 1 }; // 40 col text, page 1
 
 
 uint8_t Apple2_Dummy_Page[ 1 * PG ];            // Dummy Page to discard data
-uint8_t Apple2_Dummy_RAM[ 4 * KB ];             // Dummy RAM to discard data
+uint8_t Apple2_Dummy_RAM[ 64 * KB ];            // Dummy RAM to discard data
 
 uint8_t Apple2_16K_ROM[ 16 * KB ] = {0};        // ROM C0, C8, D0, D8, E0, E8, F0, F8
 
@@ -44,7 +44,7 @@ uint8_t * const MEM = Apple2_64K_MEM;           // Pointer to the Shadow Memory
 uint8_t * const RDLOMEM = Apple2_64K_MEM;       // Pointer to the Shadow Memory Map so we can use this from Swift
 uint8_t * const WRLOMEM = Apple2_64K_MEM;       // Pointer to the Shadow Memory Map so we can use this from Swift
 uint8_t * const RDHIMEM = Apple2_64K_MEM;       // Pointer to the Shadow Memory Map so we can use this from Swift
-uint8_t * const WRHIMEM = Apple2_64K_MEM;       // Pointer to the Shadow Memory Map so we can use this from Swift
+uint8_t * const WRHIMEM = Apple2_Dummy_RAM;     // Pointer to the Shadow Memory Map so we can use this from Swift
 
 
 
@@ -941,7 +941,7 @@ INLINE uint16_t memread16( uint16_t addr ) {
 
 INLINE uint8_t memread( uint16_t addr ) {
     if (addr >= 0xC000) {
-        if (addr <= 0xC0FF) {
+        if (addr < 0xC100) {
             return ioRead(addr);
         }
 
@@ -974,20 +974,38 @@ INLINE uint8_t memread( uint16_t addr ) {
 /**
  Naive implementation of RAM write to address
  **/
-static  void memwrite( uint16_t addr, uint8_t byte ) {
-//    if ( addr >= 0xD000 ) {
-//        // ROM
-//        return;
-//    }
-//    if ( addr >= 0xC000 ) {
-//        return mmioWrite(addr);
+
+INLINE void memwrite8_low( uint16_t addr, uint8_t data ) {
+    WRLOMEM[addr] = data;
+}
+INLINE void memwrite8_high( uint16_t addr, uint8_t data ) {
+    WRHIMEM[addr] = data;
+}
+INLINE void memwrite( uint16_t addr, uint8_t data ) {
+    if (addr >= 0xC000) {
+        if (addr < 0xC100) {
+            ioWrite(addr, data);
+        }
+        else {
+//    *(RAM_PG_WR_TBL[ addr >> 8 ] + (addr & 0xFF)) = data;
+           memwrite8_high(addr, data);
+        }
+    }
+    else {
+        memwrite8_low(addr, data);
+    }
+    
+//    // I/O or ROM or RAM EXP
+//    if ( ( addr >= 0xC000 ) && ( addr < 0xC100 ) ) {
+//        return ioWrite( addr, src );
 //    }
 //
-    
-    RAM[ addr ] = byte;
+//    // DO NOT MAKE IT NICER! faster this way!
+//    *(RAM_PG_WR_TBL[ addr >> 8 ] + (addr & 0xFF)) = src;
+////    RAM[addr] = src;
+//
 }
 
-
 /**
  Fetching 1 byte from memory address pc (program counter)
  increase pc by one