External Connections
VL-486-4 Reference Manual
Installation – 53
J5 – C
OUNTER
/T
IMER
- D
IGITAL
I/O - I
NTERRUPT
C
ONNECTOR
A 14-pin header connector, J5, provides external access to a variety of Counter/Timer, Digital
I/O and Interrupt signals.
Table 29: CT/DIO/INT Connector Pinout.
J5
Pin
Signal
Name
Function
1
PC0
Port C Data 0
, Counter/Timer 3 Output
2
Ground
Ground
3
PC1
Port C Data 1
, Counter/Timer 3 Count Input
4
Ground
Ground
5
PC2
Port C Data 2
, Counter/Timer 3 Trigger Input
6
Ground
Ground
7
PC3
Port C Data 3
, Counter/Timer 3 Gate Input
8
Ground
Ground
9
FPI1*
Front Plane Interrupt 1
10
Ground
Ground
11
FPI2*
Front Plane Interrupt 2
12
Ground
Ground
13
FPI3*
Front Plane Interrupt 3
14
Ground
Ground
PC0-PC3 — Port C I/O Lines.
These TTL input/output signals are used to as wait and request
lines for DIO Ports A and B, to provide external access to DIO Counter/Timer 3, or as four bits
of parallel I/O accessed through Port C.
FPI1* — Front Plane Interrupt 1.
This TTL input signal is used as a general purpose
interrupt request input. If jumper V10[2-3] is inserted, a low level (or high-to-low transition)
applied to the FPI1* pin will request an interrupt via IRQ3. In DOS configuration, this will cause
an INT 0Bh resulting in a dispatch through the interrupt vector at 000:002Ch.
FPI2* — Front Plane Interrupt 2.
This TTL input signal is used as a general purpose
interrupt request input. If jumper V11[2-3] is inserted, a low level (or high-to-low transition)
applied to the FPI2* pin will request an interrupt via IRQ11. In DOS configuration, this will
cause an INT 0Bh resulting in a dispatch through the interrupt vector at 000:002Ch.
FPI3* — Front Plane Interrupt 3.
This TTL input signal is used as a general purpose
interrupt request input. If jumper V12[2-3] is inserted, a low level (or high-to-low transition)
applied to the FPI3* pin will request an interrupt via IRQ12. In DOS configuration this will
cause an INT 74h resulting in a dispatch through the interrupt vector at 0000:01D0h.
