Resolution
The earliest video games from the Bronze Age (1972-1980) used television sets. Photos of Pong show the set in a full plastic case, tuner knobs and all. Manufacturers like Midway quickly developed monitors with television tubes and none of the tuner electronics. The ubiquitous tube of the time was a 19” or 22” monochrome (Black and White) Television tube.
Those tubes dictated the 336 pixel x 240 line resolution. When color crept in during the Golden Age (1980- 1985) the resolution was the same because the NTSC ensured backward compatibility with older monochrome sets. Resolutions also varied because the NTSC standard allows for the plastic case to cover portions of the tube. A fully exposed tube designed to the maximum of the standard would be 456 x 262 in full overscan.
As personal computers made Video Graphics hardware cheaper the industry moved to Medium resolution (512 x 288) and eventually the VGA standard (640 x 480).
Each change in resolution would require a change in the Shadow Mask of the monitor. This makes tube swapping a challenge. Newer games are using the flat screen technologies and XGA drivers.
Technical Specification Table
| Resolution | Pixels | Lines | Clock |
|---|---|---|---|
| Standard | 336 (456) | 240 (262) | 7.16 MHz |
| Medium | 512 (640) | 384 (416) | 16.00 MHz |
| VGA* | 640 | 480 | 25.175 MHz |
| Extended | 512 (646) | 288 (312) | 10.67 MHz |
| VGA20 | 512 (634) | 384 (450) | 20.00 MHz |
*not an NTSC Standard, no overscan numbers given.