VAST 32 TTL Digital LogicBoard (V32TTL)

General Description

The V32TTL provides 32 TTL level digital I/O lines. Lines can be individually configured as inputs or outputs.

Quick Start

1. Install ADDR jumpers to pins 1-2, 3-4, 5-6 and 7-8 (as shipped). This puts the board at VAST address 0, with the I/O lines at bit numbers 0 through 31.

2. Connect the VAST cable to the SBC2000.

3. Execute the following code:

SUBROUTINE delay(arg AS INTEGER) 
	LOCAL index AS INTEGER 
	FOR index = 0 TO arg 
		REM 
	NEXT index 
END 
CONSTANT crlf AS STRING = "\013\010" 
GLOBAL line AS INTEGER 
REM read the state of all 32 inputs 
VDIO_CONFIG(0,1)
PRINT crlf, "Start" 
FOR line = 0 TO 31 
	PRINT crlf, VTEST(line) 
NEXT line 

Software Control

• VDIO_CONFIG() configures digital I/O. When executed with func=0 and value=1 this subroutine configures the commands that use the
• V32TTL. This statement is usually executed only once, unless you are also using digital hardware that requires a different digital configuration.
• VSET() will configure the line as an output and set the output to high. Valid output numbers are 0 to 479.
• VRESET() will configure line as an output and set the output to low.
• VTEST() will configure the line as an input and return the state of the input. Valid inputs are 0 to 479. VINP() will return an 8 bit byte from the specified port, reading 8 inputs at a time. Valid port addresses are 0 to 59.
• VOUT() will write the specified byte to the specified port, setting 8 outputs at a time.

See the Vesta Multi-Tasking Basic manual for information on how these commands are used.

V32TTL Address Jumpers

I/O Connector

• Port 0 = DIO 0-7
• Port 1 = DIO 8-15
• Port 2 = DIO 16-23
• Port 3 = DIO 24-31

Power Requirements

The current draw for a V32TTL is 2mA for board logic when outputs are unloaded.

V32TTL Dimension Drawing

Dimensions are in inches.

V32TTL Schematic