CRT:IBM 8503

The IBM 8503 Personal System/2 Monochrome Display is the original VGA (and 31 kHz VGA only) black and white monitor, along with its premium color equivalent - the 8513.

As to IBM tradition, the full model number (MT/M) is made of a 4-character family (8503) and a 3-character specification, here indicating input mains voltage (001 is North American spec, 002 European, ...)

It runs somewhat hot due to the large resistors used in the linear power supply; electrically, however, it's a cold chassis design using a full size isolation transformer (after the socket, switch, and fuse). The high voltage connector is made of somewhat hard clear plastic which tends to retract over the years, leaving a gap for dust to get into.

It pre-dates DPMS and EDID, and does not have any OSD except for a test pattern (white screen with uncontrolled height if pin 5 is not grounded). Unused pins are not present, making it compatible with sockets that have pin 9 filled. For best compatibility with sources that do not expect such a display, an EDID & channel mixer box is desirable.

Flyback: TFB-648E, secondary 18 kV

Controls
As factory configured, the image is significantly underscanned.

External

 * Power, Brightness (with 50% stop), Contrast

Internal

 * Centering, Geometry (magnetical)
 * H/V Size
 * Static and Dynamic focus
 * Video gain (sub contrast), on neck board