|Backspace||Backup one column|
|Shift Delete||Un-punch column (magic punch-card white-out)|
|Home, Ctrl-B||Jump to column 1|
|Delete, Ctrl-X||Discard current card. Leaves punch station empty.|
|Insert, Ctrl-N||Release current card, insert new blank card.|
|F1, Ctrl-A||Toggle between Program Card and current data card view. The column indicator is highlighted yellow when the program card is in the punch station.|
|Shift F1||Replace program card with current card (from punching station).|
"Feed" and "Release" should work similar to original equipment. There is no "Register" key, and no pre-feeding. Feeding a card will register it at the same time. "Auto Feed" affects handling at the end of a card after manually punching, "Release, "Skip" or "Dup".
The input hopper is located in the upper left. Output stacker is located in the upper right. The hopper and stacker behave in the normal fashion.
Located to the right of the stacker is an indicator of the "reading station" status, either empty or 1 card present. This serves as a reminder to clear this card also before saving stacker contents.
Right of the reading station is the program enable lever. This effectively engages the program "star wheels" with the program card.
Above the program enable lever is the column indicator. This shows what column will be punched next. This indicator will be yellow when the program card is in the punching station.
Punched cards are saved as 80 16-bit integers (little-endian), with bits 11-0 having the punched rows (bit 11 = 12-Punch, bit 10 = 11-Punch, bit 9 = Zero-Punch, ... bit 0 = Nine-Punch). Bit 12 indicates whether the column should be printed (printer was on when the column was punched, or the column was later run through the interpreter).
Note that printing does not overstrike. When a column is multi-punched, the printed symbol changes as punches are added. Invalid (unknown) punch combinations are shown as blank.