71B: DISP, KEY$, and keyboard buffer

[Dave Britten]

(04-23-2021 06:25 PM)J-F Garnier Wrote:  Ah, the SCROLL statement is made exactly for this purpose: following a DISP it pauses execution, lets the user scroll the line if needed, and resumes execution after a key different from the left/right arrows is pressed.
SCROLL lets you specify the starting position, and doesn't eat the terminating key (you may still need a KEY$).

SCROLL is available is the FORTH/Assembler module, or in various LEX files (CUSTUTIL, STRUTIL, USERLIBA, ULIB52, ...).

Many solutions now...

J-F

Cool, I'll have to check out those LEX files and see what other goodies they might hold.

I think my approach will be something like this:

GDISP "" after a DISP (or other pause) that's followed by lengthy processing, just to indicate that something is happening and the computer isn't still waiting for a keystroke.

K$=KEY$ to "eat" the keystroke that was used to continue after DISP when it's followed by something that accepts user input. I noticed it's sometimes useful to actually act on that keystroke so you can detect the up arrow and back up to the previous DISP, for example.

I do kind of wish the 71B had a pair of commands like Sharp computers' PRINT and PAUSE, or HP calculators' R/S and PSE, i.e. one that means "display and wait for a key before continuing", and one that means "display briefly and then continue", but the options it does have are workable enough I think.