15C flashing display


Today, when I turned my 15C on (having been off for a couple of weeks), the display was flashing, showing the contents of the X-register. When I hit the Clx key (back arrow), it stopped flashing. The self test and the keyboard test ran fine, and it seems to be working fine. Anybody have any idea why the display would flash like that?

Thanks and best regards, Hal


There are two documented ways to make the display blink as you mention:

  1. An overflow condition, where the result of some computation exceeds the available range (i.e., > 9.999999999E+99). A running program which generates an overflow will continue running, but when it eventually stops, the display will be left blinking (unless the program clears flag 9, as discussed next).

  2. Manually setting flag 9

You can stop the display blinking by pressing the backarrow key, executing CF 9, or turning off the machine. If it turns itself off, flag 9 won't be cleared.

Best regards from V.

Possibly Related Threads...
Thread Author Replies Views Last Post
  WP-34s ISP (flashing cable) again ;( Bernhard 16 1,344 11-01-2013, 05:02 PM
Last Post: Bernhard
  Re: [WP34S] Flashing Issues Les Wright 22 1,813 10-30-2013, 02:16 PM
Last Post: Les Wright
  Vintage HP 15C with bleeding LCD display Michael de Estrada 1 371 10-30-2013, 09:54 AM
Last Post: Jeff O.
  help flashing a hp30b to a wp34s john mantooth 3 431 09-25-2013, 08:58 AM
Last Post: Thomas Chrapkiewicz
  Flashing cable for HP 20 / 30B Stefan Koenig 3 486 09-19-2013, 05:53 AM
Last Post: Marcus von Cube, Germany
  USB flashing/Li-po boards patryk 6 585 09-08-2013, 12:31 PM
Last Post: patryk
  Help with flashing HP30s John Ioannidis 14 1,017 09-04-2013, 09:37 PM
Last Post: John Ioannidis
  Flashing at HHC2013 Kiyoshi Akima 1 280 08-30-2013, 09:12 AM
Last Post: Matt Kernal
  Self-made WP-34s flashing cable? Victor Koechli 6 758 08-15-2013, 10:11 AM
Last Post: Les Wright
  wp34s flashing successful at last Glenn Becker 2 314 08-04-2013, 04:33 PM
Last Post: Walter B

Forum Jump: