Early Video Cards - Zenith Z-100 Reference Manual

Page 7.42
Video Graphics Programming

Early Video Cards

If your computer is an early system, it may use a different video card instead
of the present design. The two cards are easily distinguished from each other.
The early card has seven configuration jumpers instead of eight, and the two
connectors which project from the top rear of the present card are installed on
the card field on the earlier design.
If your system uses the early design video card, you will need to use the following
information to properly set the configuration jumpers for the proper operation
of your system. Corresponding jumper numbers on the present video card do
not correspond and perform the same functions on the early design video card.
Character Font Selection
Refer to Table 7.19 for the logic governing power-up character font selection, con-
trolled by configuration jumpers J302 and J304.
Table 7.19. Character Font Selection — Early Video Card
J 304 J3 0 2
0 0
0 I
1 0
I I
Selection of a reserved option wiff result in a white screen or selection of a character
type that is not wanted.
Light Pen Polarity
If you are using a light pen with your system, position J301 to "+" for a light
pen with a positive going pulse output, or to "—" for a negative going signal.
CHARACTER FONT
Double-dot
Reserved
Single-dot
Reserved