diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index a76e43e..249a2f6 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -6,6 +6,9 @@ add_executable(${PROGRAM})
 
 target_sources(${PROGRAM} PRIVATE main.c palette.c clocks.pio.h)
 
+# generate image array source files from png images
+visrealm_generate_image_source_ram(${PROGRAM} splash res/splash.png )
+
 # generate header file from pio
 pico_generate_pio_header(${PROGRAM} ${CMAKE_CURRENT_LIST_DIR}/clocks.pio)
 
diff --git a/src/main.c b/src/main.c
index f0d7f5f..d842ae2 100644
--- a/src/main.c
+++ b/src/main.c
@@ -16,6 +16,8 @@
 
 #include "palette.h"
 
+#include "splash.h"
+
 #include "vrEmuTms9918Util.h"
 
 #include "pico/stdlib.h"
@@ -67,15 +69,22 @@
 #define GPIO_INT 22
 #define GPIO_GROMCL 29
 #define GPIO_CPUCL 23
+#define GPIO_LED 25
 
 #define GPIO_CD_MASK (0xff << GPIO_CD0)
 #define GPIO_CSR_MASK (0x01 << GPIO_CSR)
 #define GPIO_CSW_MASK (0x01 << GPIO_CSW)
 #define GPIO_MODE_MASK (0x01 << GPIO_MODE)
 #define GPIO_INT_MASK (0x01 << GPIO_INT)
+#define GPIO_LED_MASK (0x01 << GPIO_LED)
 
 #define TMS_CRYSTAL_FREQ_HZ 10738635.0f
 
+#define GPIO_CD_REVERSED 1
+#define LED_BLINK_ON_WRITE 1
+
+
+#if GPIO_CD_REVERSED
 
   /* In revision 0.2 of my prototype PCB, CD0 through CD7 are inconveniently reversed into the
      Pi Pico GPIO pins. Quickest way to deal with that is this lookup table.
@@ -101,9 +110,12 @@ static uint8_t  __aligned(4) reversed[] =
   0x07, 0x87, 0x47, 0xC7, 0x27, 0xA7, 0x67, 0xE7, 0x17, 0x97, 0x57, 0xD7, 0x37, 0xB7, 0x77, 0xF7,
   0x0F, 0x8F, 0x4F, 0xCF, 0x2F, 0xAF, 0x6F, 0xEF, 0x1F, 0x9F, 0x5F, 0xDF, 0x3F, 0xBF, 0x7F, 0xFF
 };
+#define REVERSE(x) reversed[x]
+#else
+#define REVERSE(x) x
+#endif
 
-
-/* file globals */
+  /* file globals */
 
 static VrEmuTms9918* tms = NULL;  /* our vrEmuTms9918 instance handle */
 static uint32_t nextValue = 0; /* TMS9918A read-ahead value */
@@ -128,7 +140,7 @@ void __time_critical_func(gpioExclusiveCallbackProc1)()
 
     if (gpios & GPIO_MODE_MASK) /* read status register */
     {
-      sio_hw->gpio_out = ((uint32_t)reversed[vrEmuTms9918ReadStatus(tms)] << GPIO_CD0) | GPIO_INT_MASK;
+      sio_hw->gpio_out = ((uint32_t)REVERSE(vrEmuTms9918ReadStatus(tms)) << GPIO_CD0) | GPIO_INT_MASK;
       currentInt = GPIO_INT_MASK;
     }
     else /* read data */
@@ -139,7 +151,7 @@ void __time_critical_func(gpioExclusiveCallbackProc1)()
   }
   else if ((gpios & GPIO_CSW_MASK) == 0)  /* write? */
   {
-    uint8_t value = reversed[(sio_hw->gpio_in >> GPIO_CD0) & 0xff];
+    uint8_t value = REVERSE((sio_hw->gpio_in >> GPIO_CD0) & 0xff);
 
     if (gpios & GPIO_MODE_MASK) /* write register/address */
     {
@@ -151,15 +163,20 @@ void __time_critical_func(gpioExclusiveCallbackProc1)()
     else /* write data */
     {
       vrEmuTms9918WriteData(tms, value);
+
+#if LED_BLINK_ON_WRITE
+      sio_hw->gpio_out = GPIO_LED_MASK | currentInt;
+#endif
     }
   }
   else /* both CSR and CSW are high (inactive). Go High-Z */
   {
     sio_hw->gpio_oe_clr = GPIO_CD_MASK;
+    sio_hw->gpio_out = currentInt;
   }
 
   /* update read-ahead */
-  nextValue = reversed[vrEmuTms9918ReadDataNoInc(tms)] << GPIO_CD0;
+  nextValue = REVERSE(vrEmuTms9918ReadDataNoInc(tms)) << GPIO_CD0;
 
   /* interrupt handled */
   iobank0_hw->intr[GPIO_CSR >> 3u] = iobank0_hw->proc1_irq_ctrl.ints[GPIO_CSR >> 3u];
@@ -171,9 +188,9 @@ void __time_critical_func(gpioExclusiveCallbackProc1)()
 void proc1Entry()
 {
   // set up gpio pins
-  gpio_init_mask(GPIO_CD_MASK | GPIO_CSR_MASK | GPIO_CSW_MASK | GPIO_MODE_MASK | GPIO_INT_MASK);
+  gpio_init_mask(GPIO_CD_MASK | GPIO_CSR_MASK | GPIO_CSW_MASK | GPIO_MODE_MASK | GPIO_INT_MASK | GPIO_LED_MASK);
   gpio_put_all(GPIO_INT_MASK);
-  gpio_set_dir_all_bits(GPIO_INT_MASK); // int is an output
+  gpio_set_dir_all_bits(GPIO_INT_MASK | GPIO_LED_MASK); // int is an output
 
   // ensure CSR and CSW are high (inactive)
   while (!gpio_get(GPIO_CSW) || !gpio_get(GPIO_CSR))
@@ -196,7 +213,7 @@ void proc1Entry()
 static void __time_critical_func(tmsScanline)(uint16_t y, VgaParams* params, uint16_t* pixels)
 {
   const uint32_t vBorder = (params->vVirtualPixels - TMS9918_PIXELS_Y) / 2;
-  const uint32_t hBorder = (params->hVirtualPixels - TMS9918_PIXELS_X) / 2;
+  const uint32_t hBorder = (params->hVirtualPixels - TMS9918_PIXELS_X * 2) / 2;
 
   uint16_t bg = tms9918PaletteBGR12[vrEmuTms9918RegValue(tms, TMS_REG_FG_BG_COLOR) & 0x0f];
 
@@ -207,6 +224,30 @@ static void __time_critical_func(tmsScanline)(uint16_t y, VgaParams* params, uin
     {
       pixels[x] = bg;
     }
+
+
+    /* source: C:/Users/troy/OneDrive/Documents/projects/pico9918/src/res/splash.png
+     * size  : 172px x 10px
+     *       : 3440 bytes
+     * format: 16bpp abgr image
+     */
+    if (y >= vBorder + TMS9918_PIXELS_Y + 12)
+    {
+      y -= vBorder + TMS9918_PIXELS_Y + 12;
+      if (y < 10)
+      {
+        uint16_t* splashPtr = splash + (y * 172);
+        for (int x = 4; x < 4 + 172; ++x)
+        {
+          uint16_t c = *(splashPtr++);
+          if (c & 0xf000)
+          {
+           pixels[x] = c;
+          }
+        }
+      }
+    }
+
     return;
   }
 
@@ -225,13 +266,24 @@ static void __time_critical_func(tmsScanline)(uint16_t y, VgaParams* params, uin
 
   /* convert from tms palette to bgr12 */
   int tmsX = 0;
-  for (int x = hBorder; x < hBorder + TMS9918_PIXELS_X; ++x, ++tmsX)
+  if (tmsScanlineBuffer[0] & 0xf0)
   {
-    pixels[x] = tms9918PaletteBGR12[tmsScanlineBuffer[tmsX]];
+    for (int x = hBorder; x < hBorder + TMS9918_PIXELS_X * 2; x += 2, ++tmsX)
+    {
+      pixels[x] = tms9918PaletteBGR12[(tmsScanlineBuffer[tmsX] & 0xf0) >> 4];
+      pixels[x + 1] = tms9918PaletteBGR12[tmsScanlineBuffer[tmsX] & 0x0f];
+    }
+  }
+  else
+  {
+    for (int x = hBorder; x < hBorder + TMS9918_PIXELS_X * 2; x += 2, ++tmsX)
+    {
+      pixels[x] = pixels[x + 1] = tms9918PaletteBGR12[tmsScanlineBuffer[tmsX] & 0x0f];
+    }
   }
 
   /*** right border ***/
-  for (int x = hBorder + TMS9918_PIXELS_X; x < params->hVirtualPixels; ++x)
+  for (int x = hBorder + TMS9918_PIXELS_X * 2; x < params->hVirtualPixels; ++x)
   {
     pixels[x] = bg;
   }
@@ -246,9 +298,6 @@ static void __time_critical_func(tmsScanline)(uint16_t y, VgaParams* params, uin
 
 /*
  * initialise a clock output using PIO
- *
- * GROMCLK is crystal frequency / 24 (~447KHz)
- * CPUCLK is crystal frequency / 3 (~3.58MHz)
  */
 uint initClock(uint gpio, float freqHz)
 {
@@ -295,8 +344,14 @@ int main(void)
 
   /* then set up VGA output */
   VgaInitParams params = { 0 };
-  params.params = vgaGetParams(VGA_640_480_60HZ, 2);
+  params.params = vgaGetParams(VGA_640_480_60HZ);
+
+  /* virtual size will be 640 x 320 to accomodate 80-column mode */
+  setVgaParamsScaleY(&params.params, 2);
+
+  /* set vga scanline callback to generate tms9918 scanlines */
   params.scanlineFn = tmsScanline;
+
   vgaInit(params);
 
   /* signal proc1 that we're ready to start the display */
diff --git a/src/vga/vga-modes.c b/src/vga/vga-modes.c
index bd05790..4764516 100644
--- a/src/vga/vga-modes.c
+++ b/src/vga/vga-modes.c
@@ -16,10 +16,8 @@ void vgaUpdateTotalPixels(VgaSyncParams* params);
 /*
  * populate VgaParams for known vga modes
  */
-VgaParams vgaGetParams(VgaMode mode, int pixelScale)
+VgaParams vgaGetParams(VgaMode mode)
 {
-  if (pixelScale < 1) pixelScale = 1;
-
   VgaParams params;
 
   switch (mode)
@@ -112,14 +110,44 @@ VgaParams vgaGetParams(VgaMode mode, int pixelScale)
     params.vSyncParams.freqHz = 1.0f / frameTimeSeconds;
   }
 
-  params.hPixelScale = pixelScale;
-  params.vPixelScale = pixelScale;
-  params.hVirtualPixels = (params.hSyncParams.displayPixels / params.hPixelScale);
-  params.vVirtualPixels = (params.vSyncParams.displayPixels / params.vPixelScale);
+  setVgaParamsScale(&params, 1);
 
   return params;
 }
 
+/*
+ * set the scale/multiplier of virtual pixel size
+ */
+bool setVgaParamsScale(VgaParams* params, int pixelScale)
+{
+  return setVgaParamsScaleX(params, pixelScale) &&
+    setVgaParamsScaleY(params, pixelScale);
+}
+
+bool setVgaParamsScaleXY(VgaParams* params, int pixelScaleX, int pixelScaleY)
+{
+  return setVgaParamsScaleX(params, pixelScaleX) &&
+    setVgaParamsScaleY(params, pixelScaleY);
+}
+
+bool setVgaParamsScaleX(VgaParams* params, int pixelScale)
+{
+  if (!params || pixelScale < 1) return false;
+
+  params->hPixelScale = pixelScale;
+  params->hVirtualPixels = (params->hSyncParams.displayPixels / params->hPixelScale);
+  return true;
+}
+
+bool setVgaParamsScaleY(VgaParams* params, int pixelScale)
+{
+  if (!params || pixelScale < 1) return false;
+
+  params->vPixelScale = pixelScale;
+  params->vVirtualPixels = (params->vSyncParams.displayPixels / params->vPixelScale);
+  return true;
+}
+
 /*
  * update total number of pixels
  */
diff --git a/src/vga/vga-modes.h b/src/vga/vga-modes.h
index 3fb1114..f83b440 100644
--- a/src/vga/vga-modes.h
+++ b/src/vga/vga-modes.h
@@ -22,4 +22,16 @@ typedef enum
   VGA_1280_1024_60HZ,
 } VgaMode;
 
-extern VgaParams vgaGetParams(VgaMode mode, int pixelScale);
+
+/*
+ * get the vga parameters for known modes
+ */
+VgaParams vgaGetParams(VgaMode mode);
+
+/*
+ * set the scale/multiplier of virtual pixel size
+ */
+bool setVgaParamsScale(VgaParams* params, int pixelScale);
+bool setVgaParamsScaleXY(VgaParams* params, int pixelScaleX, int pixelScaleY);
+bool setVgaParamsScaleX(VgaParams* params, int pixelScale);
+bool setVgaParamsScaleY(VgaParams* params, int pixelScale);
\ No newline at end of file
diff --git a/src/vga/vga.c b/src/vga/vga.c
index b052975..6b5d484 100644
--- a/src/vga/vga.c
+++ b/src/vga/vga.c
@@ -35,10 +35,13 @@
 #define SYNC_SM         0        // vga sync state machine index
 #define RGB_SM          1        // vga rgb state machine index
 
-
 #define END_OF_SCANLINE_MSG 0x40000000
 #define END_OF_FRAME_MSG 0x80000000
 
+#define CRT_EFFECT 0
+#define SCANLINE_TIME_DEBUG 1
+
+
  /*
   * sync pio dma data buffers
   */
@@ -46,16 +49,22 @@ uint32_t __aligned(4) syncDataActive[4];  // active display area
 uint32_t __aligned(4) syncDataPorch[4];   // vertical porch
 uint32_t __aligned(4) syncDataSync[4];    // vertical sync
 
-uint16_t* rgbDataBufferEven = NULL;
-uint16_t* rgbDataBufferOdd = NULL;
+uint16_t* __aligned(4) rgbDataBuffer[2 + SCANLINE_TIME_DEBUG] = { 0 };       // two scanline buffers (odd and even)
 
 /*
  * file scope
  */
 static int syncDmaChan = 0;
 static int rgbDmaChan = 0;
+static uint syncDmaChanMask = 0;
+static uint rgbDmaChanMask = 0;
 static VgaInitParams vgaParams = { 0 };
 
+#if SCANLINE_TIME_DEBUG
+bool hasRenderedNext = false;
+#endif
+
+
 uint32_t vgaMinimumPioClockKHz(VgaParams* params)
 {
   if (params)
@@ -84,8 +93,15 @@ static bool buildSyncData()
     return false;
   }
 
-  if (!rgbDataBufferEven) rgbDataBufferEven = malloc(vgaParams.params.hVirtualPixels * sizeof(uint16_t));
-  if (!rgbDataBufferOdd) rgbDataBufferOdd = malloc(vgaParams.params.hVirtualPixels * sizeof(uint16_t));
+  rgbDataBuffer[0] = malloc(vgaParams.params.hVirtualPixels * sizeof(uint16_t));
+  rgbDataBuffer[1] = malloc(vgaParams.params.hVirtualPixels * sizeof(uint16_t));
+
+#if SCANLINE_TIME_DEBUG
+  rgbDataBuffer[2] = malloc(vgaParams.params.hVirtualPixels * sizeof(uint16_t));
+
+  for (int i = 0; i < vgaParams.params.hVirtualPixels; ++i)
+    rgbDataBuffer[2][i] = 0x0f00;
+#endif
 
   vgaParams.params.pioDivider = round(sysClockKHz / (float)minClockKHz);
   vgaParams.params.pioFreqKHz = sysClockKHz / vgaParams.params.pioDivider;
@@ -102,10 +118,10 @@ static bool buildSyncData()
 
 
   // compute sync bits
-  const uint32_t hSyncOff = (vgaParams.params.hSyncParams.syncHigh ? 0 : 1) << vga_sync_WORD_HSYNC_OFFSET;
-  const uint32_t hSyncOn = (vgaParams.params.hSyncParams.syncHigh ? 1 : 0) << vga_sync_WORD_HSYNC_OFFSET;
-  const uint32_t vSyncOff = (vgaParams.params.vSyncParams.syncHigh ? 0 : 1) << vga_sync_WORD_VSYNC_OFFSET;
-  const uint32_t vSyncOn = (vgaParams.params.vSyncParams.syncHigh ? 1 : 0) << vga_sync_WORD_VSYNC_OFFSET;
+  const uint32_t hSyncOff = !vgaParams.params.hSyncParams.syncHigh << vga_sync_WORD_HSYNC_OFFSET;
+  const uint32_t hSyncOn = vgaParams.params.hSyncParams.syncHigh << vga_sync_WORD_HSYNC_OFFSET;
+  const uint32_t vSyncOff = !vgaParams.params.vSyncParams.syncHigh << vga_sync_WORD_VSYNC_OFFSET;
+  const uint32_t vSyncOn = vgaParams.params.vSyncParams.syncHigh << vga_sync_WORD_VSYNC_OFFSET;
 
   // compute exec instructions
   const uint32_t instIrq = pio_encode_irq_set(false, vga_rgb_RGB_IRQ) << vga_sync_WORD_EXEC_OFFSET;
@@ -165,6 +181,7 @@ static void vgaInitSync()
 
   // initialise sync dma
   syncDmaChan = dma_claim_unused_channel(true);
+  syncDmaChanMask = 0x01 << syncDmaChan;
   dma_channel_config syncDmaChanConfig = dma_channel_get_default_config(syncDmaChan);
   channel_config_set_transfer_data_size(&syncDmaChanConfig, DMA_SIZE_32);           // transfer 32 bits at a time
   channel_config_set_read_increment(&syncDmaChanConfig, true);                       // increment read
@@ -218,6 +235,7 @@ static void vgaInitRgb()
 
   // initialise rgb dma
   rgbDmaChan = dma_claim_unused_channel(true);
+  rgbDmaChanMask = 0x01 << rgbDmaChan;
   dma_channel_config rgbDmaChanConfig = dma_channel_get_default_config(rgbDmaChan);
   channel_config_set_transfer_data_size(&rgbDmaChanConfig, DMA_SIZE_16);  // transfer 16 bits at a time
   channel_config_set_read_increment(&rgbDmaChanConfig, true);             // increment read
@@ -225,7 +243,7 @@ static void vgaInitRgb()
   channel_config_set_dreq(&rgbDmaChanConfig, pio_get_dreq(VGA_PIO, RGB_SM, true));
 
   // setup the dma channel and set it going
-  dma_channel_configure(rgbDmaChan, &rgbDmaChanConfig, &VGA_PIO->txf[RGB_SM], rgbDataBufferEven, vgaParams.params.hVirtualPixels, false);
+  dma_channel_configure(rgbDmaChan, &rgbDmaChanConfig, &VGA_PIO->txf[RGB_SM], rgbDataBuffer[0], vgaParams.params.hVirtualPixels, false);
   dma_channel_set_irq0_enabled(rgbDmaChan, true);
 }
 
@@ -237,9 +255,9 @@ static void __time_critical_func(dmaIrqHandler)(void)
   static int currentTimingLine = -1;
   static int currentDisplayLine = -1;
 
-  if (dma_hw->ints0 & (1u << syncDmaChan))
+  if (dma_hw->ints0 & syncDmaChanMask)
   {
-    dma_hw->ints0 = 1u << syncDmaChan;
+    dma_hw->ints0 = syncDmaChanMask;
 
     if (++currentTimingLine >= vgaParams.params.vSyncParams.totalPixels)
     {
@@ -266,16 +284,34 @@ static void __time_critical_func(dmaIrqHandler)(void)
     multicore_fifo_push_timeout_us(END_OF_SCANLINE_MSG | currentTimingLine, 0);
   }
 
-
-  if (dma_hw->ints0 & (1u << rgbDmaChan))
+  if (dma_hw->ints0 & rgbDmaChanMask)
   {
-    dma_hw->ints0 = 1u << rgbDmaChan;
+    dma_hw->ints0 = rgbDmaChanMask;
 
     divmod_result_t pxLineVal = divmod_u32u32(currentDisplayLine++, vgaParams.params.vPixelScale);
     uint32_t pxLine = to_quotient_u32(pxLineVal);
     uint32_t pxLineRpt = to_remainder_u32(pxLineVal);
+    uint16_t* currentBuffer = rgbDataBuffer[pxLine & 0x01];
+
+#if CRT_EFFECT
+    if (pxLineRpt != 0)
+    {
+      for (int i = 0; i < 10; ++i)
+      {
+        currentBuffer[i] = (currentBuffer[i] >> 1) & 0x0777;
+      }
+    }
+#endif
 
-    dma_channel_set_read_addr(rgbDmaChan, (pxLine & 1) ? rgbDataBufferOdd : rgbDataBufferEven, true);
+#if SCANLINE_TIME_DEBUG
+    if (pxLineRpt != 0 && hasRenderedNext)
+    {
+      currentBuffer = rgbDataBuffer[2];
+    }
+#endif
+
+
+    dma_channel_set_read_addr(rgbDmaChan, currentBuffer, true);
 
     // need a new line every X display lines
     if ((pxLineRpt == 0))
@@ -284,14 +320,24 @@ static void __time_critical_func(dmaIrqHandler)(void)
       if (requestLine >= vgaParams.params.vVirtualPixels) requestLine -= vgaParams.params.vVirtualPixels;
 
       multicore_fifo_push_timeout_us(requestLine, 0);
+      hasRenderedNext = false;
 
       if (requestLine == vgaParams.params.vVirtualPixels - 1)
       {
         multicore_fifo_push_timeout_us(END_OF_FRAME_MSG, 0);
       }
     }
+#if CRT_EFFECT
+    else
+    {
+      for (int i = 10; i < vgaParams.params.hVirtualPixels; ++i)
+      {
+        currentBuffer[i] = (currentBuffer[i] >> 1) & 0x0777;
+      }
+    }
+#endif
+    }
   }
-}
 
 /*
  * initialise the pio dma
@@ -335,13 +381,14 @@ void vgaLoop()
         vgaParams.endOfScanlineFn();
       }
     }
-    else if (message & 0x01)
-    {
-      vgaParams.scanlineFn(message & 0xfff, &vgaParams.params, rgbDataBufferOdd);
-    }
     else
     {
-      vgaParams.scanlineFn(message & 0xfff, &vgaParams.params, rgbDataBufferEven);
+      // get the next scanline pixels
+      vgaParams.scanlineFn(message & 0xfff, &vgaParams.params, rgbDataBuffer[message & 0x01]);
+#if SCANLINE_TIME_DEBUG
+      dma_channel_set_read_addr(rgbDmaChan, rgbDataBuffer[2], true);
+      hasRenderedNext = true;
+#endif
     }
   }
 }
diff --git a/submodules/vrEmuTms9918 b/submodules/vrEmuTms9918
index ec77565..0e698da 160000
--- a/submodules/vrEmuTms9918
+++ b/submodules/vrEmuTms9918
@@ -1 +1 @@
-Subproject commit ec77565e104a2f8b5319de52d8b561cdac3b6cac
+Subproject commit 0e698da4c5b9fd284fdfe111dfc16d51274d204b
diff --git a/tools/bin2carray.py b/tools/bin2carray.py
index 49092b6..78ef626 100644
--- a/tools/bin2carray.py
+++ b/tools/bin2carray.py
@@ -25,10 +25,14 @@ def main() -> int:
     parser = argparse.ArgumentParser(
         description='Convert binary files into C-style arrays for use with the PICO-56.',
         epilog="GitHub: https://github.com/visrealm/pico-56")
-    parser.add_argument('-v', '--verbose', help='verbose output', action='store_true')
-    parser.add_argument('-p', '--prefix', help='array variable prefix', default='')
-    parser.add_argument('-o', '--out', help='output file - defaults to base input file name with .c extension')
-    parser.add_argument('-i', '--in', nargs='+', help='input file(s) to store in Pi Pico ROM - can use wildcards')
+    parser.add_argument('-v', '--verbose',
+                        help='verbose output', action='store_true')
+    parser.add_argument(
+        '-p', '--prefix', help='array variable prefix', default='')
+    parser.add_argument(
+        '-o', '--out', help='output file - defaults to base input file name with .c extension')
+    parser.add_argument('-i', '--in', nargs='+',
+                        help='input file(s) to store in Pi Pico ROM - can use wildcards')
     args = vars(parser.parse_args())
 
     outSourceFileName = args['out']
@@ -47,15 +51,16 @@ def main() -> int:
         outHeaderFileName = os.path.splitext(outSourceFileName)[0] + ".h"
         outHeaderFile = open(outHeaderFileName, "w")
 
-        outSourceFile.write(getFileHeader(outSourceFileName, inFileNames, args, isHeaderFile=False))
-        outHeaderFile.write(getFileHeader(outHeaderFileName, inFileNames, args, isHeaderFile=True))
+        outSourceFile.write(getFileHeader(
+            outSourceFileName, inFileNames, args, isHeaderFile=False))
+        outHeaderFile.write(getFileHeader(
+            outHeaderFileName, inFileNames, args, isHeaderFile=True))
 
     for infile in inFileNames:
         processFile(infile, outSourceFile,
                     outHeaderFile, args)
 
     outSourceFile.close()
-    outHeaderFile.write("\n#endif")
     outHeaderFile.close()
 
     fileList = ""
@@ -95,8 +100,7 @@ def getFileHeader(fileName, fileList, args, isHeaderFile) -> str:
     if isHeaderFile:
         baseName = args['prefix'] + "_" + os.path.basename(fileName)
         sanitizedFile = re.sub('[^0-9a-zA-Z]+', '_', baseName.upper())
-        hdrText += f"#ifndef _{sanitizedFile}\n"
-        hdrText += f"#define _{sanitizedFile}\n\n"
+        hdrText += f"#pragma once\n\n"
     else:
         hdrText += "#include \"pico/platform.h\"\n"
     hdrText += "#include <inttypes.h>"
@@ -153,9 +157,11 @@ def processFile(infile, srcOutput, hdrOutput, args) -> None:
     closeFile = False
     if srcOutput == None:
         srcOutput = open(outPathWithoutExt + ".c", "w")
-        srcOutput.write(getFileHeader(srcOutput.name, [infile], args, isHeaderFile=False))
+        srcOutput.write(getFileHeader(srcOutput.name, [
+                        infile], args, isHeaderFile=False))
         hdrOutput = open(outPathWithoutExt + ".h", "w")
-        hdrOutput.write(getFileHeader(hdrOutput.name, [infile], args, isHeaderFile=True))
+        hdrOutput.write(getFileHeader(hdrOutput.name, [
+                        infile], args, isHeaderFile=True))
         closeFile = True
 
     varName = os.path.split(infile)[1]
@@ -182,7 +188,6 @@ def processFile(infile, srcOutput, hdrOutput, args) -> None:
 
     if closeFile:
         srcOutput.close()
-        hdrOutput.write("\n#endif")
         hdrOutput.close()
 
     return
diff --git a/tools/img2carray.py b/tools/img2carray.py
index 1a8e361..9e08c5b 100644
--- a/tools/img2carray.py
+++ b/tools/img2carray.py
@@ -34,7 +34,7 @@ def main() -> int:
         '-o', '--out', help='output file - defaults to base input file name with .c extension')
     parser.add_argument('-r', '--ram', nargs='+', default='',
                         help='input file(s) to store in Pi Pico RAM - can use wildcards')
-    parser.add_argument('-i', '--in', nargs='+',
+    parser.add_argument('-i', '--in', nargs='+', default='',
                         help='input file(s) to store in Pi Pico ROM - can use wildcards')
     args = vars(parser.parse_args())
 
@@ -73,7 +73,6 @@ def main() -> int:
                          outHeaderFile, args, inRam=False)
 
     outSourceFile.close()
-    outHeaderFile.write("\n#endif")
     outHeaderFile.close()
 
     fileList = ""
@@ -118,8 +117,7 @@ def getFileHeader(fileName, romFileList, ramFileList, args, isHeaderFile) -> str
     if isHeaderFile:
         baseName = args['prefix'] + "_" + os.path.basename(fileName)
         sanitizedFile = re.sub('[^0-9a-zA-Z]+', '_', baseName.upper())
-        hdrText += f"#ifndef _{sanitizedFile}\n"
-        hdrText += f"#define _{sanitizedFile}\n\n"
+        hdrText += f"#pragma once\n\n"
     else:
         hdrText += "#include \"pico/platform.h\"\n"
     hdrText += "#include <inttypes.h>"
@@ -271,7 +269,6 @@ def processImageFile(infile, srcOutput, hdrOutput, args, inRam) -> None:
 
     if closeFile:
         srcOutput.close()
-        hdrOutput.write("\n#endif")
         hdrOutput.close()
 
     return
diff --git a/visrealm_tools.cmake b/visrealm_tools.cmake
index a8ca72b..f337928 100644
--- a/visrealm_tools.cmake
+++ b/visrealm_tools.cmake
@@ -26,6 +26,21 @@ function(visrealm_generate_image_source TARGET DST ROMSRC)
   target_sources(${TARGET} PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/${DST}.c)
 endfunction()
 
+# custom function to generate source code from images using tools/img2carray.py
+function(visrealm_generate_image_source_ram TARGET DST RAMSRC)
+  set(fullSrc ${CMAKE_CURRENT_SOURCE_DIR}/${RAMSRC})
+  cmake_path(GET fullSrc PARENT_PATH srcPath)
+
+  add_custom_command(
+      OUTPUT ${DST}.c ${DST}.h
+      COMMAND ${PYTHON} ${IMG_CONV} -r ${CMAKE_CURRENT_SOURCE_DIR}/${RAMSRC} -o ${DST}.c
+      DEPENDS ${IMG_CONV} ${srcPath}
+  )
+  target_include_directories(${TARGET} PRIVATE ${CMAKE_CURRENT_BINARY_DIR})
+  target_sources(${TARGET} PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/${DST}.c)
+endfunction()
+
+
 
 
 # custom function to generate source code from images using tools/img2carray.py