New HP-42S Replacement?

[Thomas Okken]

(09-23-2017 04:29 AM)Brian Walsh Wrote:  

(09-13-2017 04:05 AM)Thomas Okken Wrote:  [snip]
The biggest "con" is the lack of I/O; apart from the keyboard and display, all it has in the I/O department is a one-way infrared printer interface. No bi-directional infrared like the HP-48 series, no serial port, no HP-IL. The only way to get programs into it is typing them.

In other words it's just like the 42S, which has "Oh!" instead of I/O.

What is just like the 42S? What did you think I was talking about, while replying to the question "Can somebody tell me what makes the HP 42s so fantastic?"