Rushware keypad

The Rushware Keypad.

Another Rushware Keypad.

The Rushware Keypad is an input device for computers with Atari control ports, such as the Commodore 64. It provides you with a 16 key numeric keyboard for applications that support the keypad. It is not supported by the system software of Commodore computers.

Technical information

The hardware of the keypad consists of key switches, which are mounted on a PCB with a lot of diodes. When a key is pressed, the right pins in the control port are ground, while the diodes prevent the signal to flow to lines of other keys. The keypad connects the fire button and direction lines of the control port.

When a key is pressed, the fire button line is active, while the direction lines specify which key is presssed.

The following BASIC program illustrates the concept and shows which bit combinations are assigned to the keys:

10 A=PEEK(56320) AND 31
20 IF A=0 THEN PRINT "ENTER"
30 IF A=1 THEN PRINT "."
40 IF A=2 THEN PRINT "*"
50 IF A=3 THEN PRINT "/"
60 IF A=4 THEN PRINT "-"
70 IF A=5 THEN PRINT "+"
80 IF A=6 THEN PRINT "9"
90 IF A=7 THEN PRINT "8"
100 IF A=8 THEN PRINT "7"
110 IF A=9 THEN PRINT "6"
120 IF A=10 THEN PRINT "5"
130 IF A=11 THEN PRINT "4"
140 IF A=12 THEN PRINT "3"
150 IF A=13 THEN PRINT "2"
160 IF A=14 THEN PRINT "1"
170 IF A=15 THEN PRINT "0"
180 GOTO 10

If multiple keys are pressed at the same time, a bitwise AND of the key number is read.