Convergence Logic Card (Location B2) - IBM 3279 2A Maintenance Information

3279 MIM
3.6 Convergence Logic Card (Location B2)
The convergence logic card (see Figure 3-5)
provides digitally-controlled analog signals for
convergence of the display unit. The card has two
storage areas that hold the definitions of the
currents required in the convergence coils. The
digital information is converted to analog signals
and fed to the amplifier card in the main enclosure
assembly.
The· card is connected to the base logic card
through the featUl"e bus so that the stores can be
accessed and updated.
Horizontal
Retrace
Add,/
Cmd
Ply
Dec
Store
Zone
Add,
Figure 3-5. Convergence Logic Card (B2)
Chapter 3. Functional Components 3-8
Timing Model
Controls and
Horizontal
Sync Retaining
Hor'z
Chan
Reg
Vert
Chan
Reg
D/A
D/A
Sum
Horizontal Sync
IAnalog Ca,dl
Convergence Signals
(Amplifier Card)