diff --git a/src/window.s b/src/window.s
diff --git a/tools/makefile b/tools/makefile
@@ -1,7 +1,7 @@
 
 CFLAGS = -lm -lgif
 
-OBJS = gifr bytesc bitsc room spriteas resp blit vis palc
+OBJS = gifr bytesc bitsc room spriteas resp blit vis palc wani
 
 all : $(OBJS)
 

diff --git a/tools/wani.c b/tools/wani.c
@@ -0,0 +1,184 @@
+
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "imgheader.h"
+
+#define NSPANS 4
+
+#define INDEX_ROWS 32
+
+int main(int argc, char *argv[])
+{
+  int opt;
+  int verbose = 0;
+
+  char outfile[1024] = "";
+
+  while ((opt = getopt(argc, argv, "o:v")) != -1) {
+    switch (opt) {
+    case 'o':
+      strcpy(outfile, optarg);
+      break;
+    case 'v':
+      verbose = 1;
+      break;
+    default:
+      fprintf(stderr, "usage: %s [-o output file] [-v]\n",
+              argv[0]);
+      return 1;
+    }
+  }
+
+  if(!outfile[0]) {
+    fprintf(stderr, "output file name missing\n");
+    return 1;
+  }
+
+  FILE *fi = freopen(NULL, "rb", stdin);
+
+  struct imgheader h;
+  fread(&h, 1, sizeof(h), fi);
+
+  if(h.magic != IMGMAGIC) {
+    fprintf(stderr, "not an rri file\n");
+    return 1;
+  }
+
+  if(h.frames != 1) {
+    fprintf(stderr, "too many frames in input file\n");
+  }
+
+  struct imgframeheader fh;
+  fread(&fh, 1, sizeof(fh), fi);
+
+  unsigned char* buffer = malloc(fh.w * fh.h);
+  fread(buffer, 1, fh.w * fh.h, fi);
+
+  unsigned short* spantable = malloc(fh.h * NSPANS * 2);
+
+  for(int yy = 0; yy < fh.h; ++yy) {
+    spantable[yy * NSPANS + 0] = 0xff;
+    spantable[yy * NSPANS + 1] = 0;
+    spantable[yy * NSPANS + 2] = 0xff;
+    spantable[yy * NSPANS + 3] = 0;
+
+    int span = 0;
+    int lastc = -1;
+    int lastxx = 0;
+    for(int xx = 0; xx < fh.w; ++xx) {
+      int c = buffer[yy * fh.w + xx];
+      if(c != lastc && xx > 0) {
+        if(span > 4) {
+          fprintf(stderr, "too many spans in scanline %i", yy);
+          return 1;
+        }
+        spantable[yy * NSPANS + span] = xx - ((span & 1) ? 1 : 0);
+        lastxx = xx;
+        ++span;
+      }
+      lastc = c;
+    }
+  }
+
+
+  FILE *fo = fo = fopen(outfile, "wb");
+
+  unsigned short dma_table_start[4];
+  unsigned short dma_table_length[4];
+  int total_length = 0;
+  unsigned char dma_tables[4][256 * 3];
+
+  unsigned char index_tables[4][256 / INDEX_ROWS * 2];
+
+  for(int xx = 0; xx < NSPANS; xx++) {
+    int table_ofs = 0;
+    int c, lc, lyy, ayy = 0;
+    lc = spantable[xx];
+    lyy = 0;
+
+
+    // extra entry for skipping ahead
+
+    dma_tables[xx][table_ofs + 0] = 0x78;
+    dma_tables[xx][table_ofs + 1] = spantable[xx];
+    dma_tables[xx][table_ofs + 2] = 1;
+    table_ofs += 3;
+
+
+    // table entries
+
+    int index = 0;
+
+
+    for(int yy = 0; yy < fh.h; yy++) {
+
+      if((yy % INDEX_ROWS) == 0) {
+        index_tables[xx][index * 2 + 0] = table_ofs / 3;
+        index_tables[xx][index * 2 + 1] = lyy;
+        ++index;
+      }
+
+      c = spantable[yy * NSPANS + xx];
+      if(c != lc) {
+        /* printf("%i, %i\n", yy - lyy, lc); */
+        dma_tables[xx][table_ofs + 0] = yy - lyy;
+        dma_tables[xx][table_ofs + 1] = lc;
+        dma_tables[xx][table_ofs + 2] = 1;
+        table_ofs += 3;
+        lc = c;
+        ayy = lyy;
+        lyy = yy;
+      }
+
+
+    }
+
+    /* printf("----\n"); */
+
+    // disable window
+
+    for(; index < 256 / INDEX_ROWS; ++index) {
+      index_tables[xx][index * 2 + 0] = table_ofs / 3;
+      index_tables[xx][index * 2 + 1] = 0xff;
+    }
+
+    dma_tables[xx][table_ofs + 0] = 0x7f;
+    dma_tables[xx][table_ofs + 1] = spantable[xx];
+    dma_tables[xx][table_ofs + 2] = 1;
+    table_ofs += 3;
+
+    // end of table
+
+    dma_tables[xx][table_ofs] = 0;
+    dma_table_length[xx] = table_ofs + 1;
+    total_length += dma_table_length[xx];
+  }
+
+  dma_table_start[0] = 8 + sizeof(index_tables);
+  dma_table_start[1] = dma_table_start[0] + dma_table_length[0];
+  dma_table_start[2] = dma_table_start[1] + dma_table_length[1];
+  dma_table_start[3] = dma_table_start[2] + dma_table_length[2];
+
+  /* for(int xx = 0; xx < 4; ++xx) */
+  /*   for(int yy = 0; yy < 16; ++yy) */
+  /*     index_tables[xx][yy * 2] += dma_table_start[xx]; */
+
+  fwrite(dma_table_start, 2, 4, fo);
+
+  fwrite(index_tables, 1, sizeof(index_tables), fo);
+
+  fwrite(dma_tables[0], 1, dma_table_length[0], fo);
+  fwrite(dma_tables[1], 1, dma_table_length[1], fo);
+  fwrite(dma_tables[2], 1, dma_table_length[2], fo);
+  fwrite(dma_tables[3], 1, dma_table_length[3], fo);
+
+  fclose(fo);
+
+  free(spantable);
+  free(buffer);
+
+  return 0;
+}