[old_tv_nut]

It appears that the bit depth is 6 bits (18 bits per pixel). It's not directly stated whether rows/columns correspond to TV samples/lines or vice versa, but the number of each implies rows = samples and columns = lines. So, 320 samples per line and 256 lines. This is plenty of lines for NTSC, and about 11% short for PAL/SECAM. 320 samples per line cuts the horizontal resolution to about 45 to 50% of broadcast resolution, depending on how much aliasing you accept. However, since this a VHS-C device, it's analog resolution is already in that range, so the sampling is not a significant limitation.