HP67 calculator issue
The on-off switch on my iPhone 8+ is backwards. To turn on the calculator it will only work when the switch is turned to the off position. The programs that shows charting needs instruction on how the program works. It appears that the plots are using a program on the internet that the developer probably created. So the plotting will not work unless the internet is available. A write up on how to create a data card and what the restrictions are (eg, the minimum and maximum number of data points allowed). I think this version of the hp67 is generally good but compared to other emulators available, needs to be updated. I didn’t notice if there are the various programs available like I see in other emulator programs. John W.