Editing IBM Monochrome Display Adapter (section)

==Specifications==

[[File:Numbered DE9 female Diagram.svg|thumb|[[D-subminiature|DE-9 connector]], looking at back of PC]]MDA cards used a DE-9 output port intended for a digital TTL monitor, like the IBM monochrome monitor.

{| class="wikitable" style="font-size:small"
|+ MDA connector pin assignments<ref name=":0">IBM Personal Computer Hardware Library: Technical Reference (Revised edition, 1983).</ref><ref name="auto"/><ref name=":1" />
|-
! Pin
! Function
|-
| 1 || [[Ground (electricity)|Ground]]
|-
| 2 || Ground
|-
| 3, 4, 5 || Not used
|-
| 6 || Intensity
|-
| 7 || [[Raster scan|Video]]
|-
| 8 || [[Horizontal sync]] (+)
|-
| 9 || [[Refresh rate|Vertical sync]] (−)
|}

The signal had the following specifications:
* '''Type''': Digital, TTL
* '''Resolution''': 720&nbsp;×&nbsp;350
* '''Horizontal frequency''': 18.432&nbsp;kHz
* '''Vertical frequency''': 50&nbsp;Hz
* '''Colors''': Monochrome, with 2 to 4 intensity levels (depending on monitor)<ref name="auto" /><ref>There are four possible combinations of values for the 'Intensity' and 'Video' pins, but not all monitors will display them as four distinct intensity levels.</ref>