Casio PV-1000/Video

The PV-1000's video timing divides a frame into 288 pixels horizontally by 262 scanlines. The pixel clock is the crystal divided by 4, or roughly 4.47MHz. This corresponds to an exact pixel aspect ratio of 48:35, or approximately 4:3. This makes the horizontal sync rate the quite-slow 15536Hz and the vertical sync rate the almost-normal 59.299Hz

Of those 288 pixels, 224 contain actual video content. These 224 pixels are already significantly wider than the majority of contemporary or even modern TVs can display.

Of the 262 scanlines, 192 contain actual video content. This is significantly shorter than the majority of TVs display. The ASIC draws a solid color of the programmers' choice for 26 scanlines each above and below.

On the 192 active scanlines, the ASIC asserts /BUSREQ for 248 pixels so that the Z80 gets out of the way in time for the ASIC to drive the video, starting 32px before.

A visualization of the tables to the left, starts with black for horizontal sync

Rendering scanlines (n=244; 0-217 and 236-261):

■	name	start	duration	notes
■	horizontal sync	0	22
■	colorburst	22	14
■	back porch, continued (black)	36	16
■	active	52	224	On scanlines 0-191, contents drawn according to fetches.
■	border			On scanlines 192-217 and 236-261, contents drawn according to border color register.
■	front porch (black)	276	12

Post-render blanking scanlines (n=3; 218-220):

■	name	start	duration	notes
■	horizontal sync	0	22
■	colorburst	22	14
■	blanking	36	252

Vertical sync scanlines (n=3; 221-223):

■	name	start	duration	notes
■	horizontal sync	0	22
■	vertical sync and colorburst (but colorburst ignored by component-to-chroma modulator)	22	14
■	vertical sync	36	230
■	vertical sync separator (black)	266	22

Pre-render blanking scanlines (n=12; 224-235):

■	name	start	duration	notes
■	horizontal sync	0	22
■	colorburst	22	14
■	blanking	36	252