Supplied with the Extended 80-column text card supplement, the ERRATA sheet tells programmers not to use the INPUT and GET statements in Applesoft when using the 80-column card. In fact, the Applesoft INPUT statement will work fine with the 80-column card.
The GET statement will not put the cursor where it belongs on the screen. This is because GET does not use the monitor routines the way the 80-column card should be used.