(Note: this circuit uses an older version of my 7447 model which is not correct. It uses positive output logic, which is how the 7448 works. It also does not model codes above 9 properly. Students can still use it for modeling purposes though they actually have a common-anode display and a 7447. Newer 7447 and 7448 models have been created.)

Basic file with subcircuits for 74xx163 and 74xx191 counters and a modified 74xx47 BCD-to-7-segment display driver. All functions of the two counters are modeled.

• Both count synchronously. 
• The '163 has synchronous clearing and loading. 
• The '191 counts up or down and loads asynchronously. 
• Timing is not modeled.

The 74xx47 model has high outputs to turn on the 7-segment display in CircuitVerse. The actual '47 has low outputs to turn on a common-anode 7-segment display. Also the  /BI function is not modeled. The common /BI-/RBO pin is wire-ANDed in the chip and not easily implemented in CircuitVerse. The /RBI and /RBO functions are implemented.

VCC and GND are dummy input pins not connected  internally in the subcircuits but are included for schematic documentation.