points by DonHopkins 7 years ago

Speaking of weird BASIC features, does anyone know why DECSYSTEM 20's BASIC had a "LISTREVERSE" command?

Yes, it actually did exactly what it sounds like!

Chalk one up for DEC and BASIC. What other programming languages support that feature, huh?

https://imgur.com/a/Bt40M

    DECSYSTEM 20 BASIC User's Guide: LISTREVERSE command

    LISTREVERSE
    LISTNHREVERSE

    LISTREVERSE and LISTNHREVERSE print the contents of the
    user's memory area in order of descending line numbers. 
    LISTREVERSE precedes the output with a heading,
    LISTNHREVERSE eliminates the heading.

    LISTREVERSE

    EQUIV             10:53                      13-NOV-75

    40    END
    35    PRINT "THE EQUIVALENT CURRENT IS",I, " AMPERES"
    25    I=E1/R
    10    INPUT R
    5     INPUT E1

    READY

http://www.bitsavers.org/www.computer.museum.uq.edu.au/pdf/D...

tom_ 7 years ago

If you're using a printer, presumably you might sometimes want the stuff at the top of the program to be last on the printout, so it's easy to get at without having to flip through a pile of paper?

Same might go for a terminal with no scrollback...

Come to think of it, this sounds actually rather useful. Had this been available when I was programming on the BBC Micro, I bet I'd have used it.

  • DonHopkins 7 years ago

    Emacs should have an edit-reverse-mode!