diff --git a/common/tranzputer.c b/common/tranzputer.c
index 00d4e18..b2d996b 100644
--- a/common/tranzputer.c
+++ b/common/tranzputer.c
@@ -1937,8 +1937,11 @@ void loadTranZPUterDefaultROMS(void)
         {
             fillZ80Memory(MZ_MROM_STACK_ADDR, MZ_MROM_STACK_SIZE, 0x00, 1);
         }
-    z80Control.disableRefresh = 1;
+
+        // No longer need refresh on the mainboard as all operations are in static RAM.
+        z80Control.disableRefresh = 1;
     }
+    return;
 }
 
 // Method to set the service status flag on the Z80 (and duplicated in the internal
@@ -2867,6 +2870,22 @@ void processServiceRequest(void)
             status=svcCacheDir((const char *)svcControl.directory, 0);
             break;
 
+        // Load the 40 column version of the SA1510 bios into memory.
+        case TZSVC_CMD_LOAD40BIOS:
+            if((status=loadZ80Memory((const char *)MZ_ROM_SA1510_40C, 0, MZ_MROM_ADDR, 0, 0, 1)) != FR_OK)
+            {
+                printf("Error: Failed to load %s into tranZPUter memory.\n", MZ_ROM_SA1510_40C);
+            }
+            break;
+          
+        // Load the 80 column version of the SA1510 bios into memory.
+        case TZSVC_CMD_LOAD80BIOS:
+            if((status=loadZ80Memory((const char *)MZ_ROM_SA1510_80C, 0, MZ_MROM_ADDR, 0, 0, 1)) != FR_OK)
+            {
+                printf("Error: Failed to load %s into tranZPUter memory.\n", MZ_ROM_SA1510_80C);
+            }
+            break;
+
         default:
             break;
     }
diff --git a/include/tools.h b/include/tools.h
index 8856d0c..8758a14 100644
--- a/include/tools.h
+++ b/include/tools.h
@@ -103,7 +103,7 @@ extern "C" {
 #define CMD_APP_MBASIC            141              // Mini Basic
 #define CMD_APP_KILO              142              // Kilo Editor
 #define CMD_APP_ED                143              // Ed Editor
-#define CMD_TZ_ZPU                150              // tranZPUter interface/test.
+#define CMD_TZ_TZPU               150              // tranZPUter interface/test.
 #define CMD_TZ_LOAD               151              // tranZPUter memory load/save tool.
 #define CMD_TZ_DUMP               152              // tranZPUter memory dump tool.
 #define CMD_TZ_CLEAR              153              // tranZPUter memory clear tool.
diff --git a/include/tranzputer.h b/include/tranzputer.h
index 8facdd7..16f1199 100755
--- a/include/tranzputer.h
+++ b/include/tranzputer.h
@@ -115,6 +115,8 @@
 #define TZSVC_CMD_SAVEFILE           0x09                                // Service command to save a file directly from tranZPUter memory.
 #define TZSVC_CMD_ERASEFILE          0x0A                                // Service command to erase a file on the SD card.
 #define TZSVC_CMD_CHANGEDIR          0x0B                                // Service command to change active directory on the SD card.
+#define TZSVC_CMD_LOAD40BIOS         0x20                                // Service command requesting that the 40 column version of the SA1510 BIOS is loaded.
+#define TZSVC_CMD_LOAD80BIOS         0x21                                // Service command requesting that the 80 column version of the SA1510 BIOS is loaded.
 #define TZSVC_DEFAULT_DIR            "MZF"                               // Default directory where MZF files are stored.
 #define TZSVC_DEFAULT_EXT            "MZF"                               // Default file extension for MZF files.
 #define TZSVC_DEFAULT_WILDCARD       "*"                                 // Default wildcard file matching.
diff --git a/libraries/lib/libimath2-k64f.a b/libraries/lib/libimath2-k64f.a
index 8fb4532..1382a59 100644
Binary files a/libraries/lib/libimath2-k64f.a and b/libraries/lib/libimath2-k64f.a differ
diff --git a/libraries/lib/libumansi-k64f.a b/libraries/lib/libumansi-k64f.a
index 8ec43aa..ae91167 100644
Binary files a/libraries/lib/libumansi-k64f.a and b/libraries/lib/libumansi-k64f.a differ
diff --git a/libraries/lib/libummath-k64f.a b/libraries/lib/libummath-k64f.a
index 6420cd7..175dc5f 100644
Binary files a/libraries/lib/libummath-k64f.a and b/libraries/lib/libummath-k64f.a differ
diff --git a/libraries/lib/libummathf-k64f.a b/libraries/lib/libummathf-k64f.a
index 292edf2..8888f23 100644
Binary files a/libraries/lib/libummathf-k64f.a and b/libraries/lib/libummathf-k64f.a differ
diff --git a/libraries/lib/libummisc-k64f.a b/libraries/lib/libummisc-k64f.a
index c64e663..029e7d3 100644
Binary files a/libraries/lib/libummisc-k64f.a and b/libraries/lib/libummisc-k64f.a differ
diff --git a/libraries/lib/libumstdio-k64f.a b/libraries/lib/libumstdio-k64f.a
index a28319e..a77edb2 100644
Binary files a/libraries/lib/libumstdio-k64f.a and b/libraries/lib/libumstdio-k64f.a differ
diff --git a/startup/app_k64f_crt0.s b/startup/app_k64f_crt0.s
index ed26070..0772580 100644
--- a/startup/app_k64f_crt0.s
+++ b/startup/app_k64f_crt0.s
@@ -372,5 +372,5 @@ BSS_END:    .word      __bss_section_end__
             .equ funcAddr,  funcAddr+funcNext;
             defapifunc      loadTranZPUterDefaultROMS funcAddr
             .equ funcAddr,  funcAddr+funcNext;
-            defapifunc      convertSharpFilename      funcAddr
+            defapifunc      convertSharpFilenameToAscii funcAddr
     .end
diff --git a/startup/mk20dx128.c b/startup/mk20dx128.c
index 373f869..0089c28 100644
--- a/startup/mk20dx128.c
+++ b/startup/mk20dx128.c
@@ -1021,7 +1021,7 @@ void _ZPUTA_Vectors(void)
     __asm__ volatile ("b getZ80IO");
     __asm__ volatile ("b clearZ80Reset");
     __asm__ volatile ("b loadTranZPUterDefaultROMS");
-    __asm__ volatile ("b convertSharpFilename");
+    __asm__ volatile ("b convertSharpFilenameToAscii");
   #endif
 }
 
diff --git a/zOS/src/zOS.cpp b/zOS/src/zOS.cpp
index 3dc8a1c..077516b 100644
--- a/zOS/src/zOS.cpp
+++ b/zOS/src/zOS.cpp
@@ -283,7 +283,7 @@ printf("Got an IO request, addr:%02x, Data:%02x\n", ioAddr, ioData);
         // Indicate the thread is free.
         //
         G.ctrlThreadBusy = 0;
-        threads.delay(100);
+        threads.delay(1);
         threads.yield();
     }
 }