Re: Reset $er to 0

[cld@xxxxxxxx (Carl Distefano)]

Reply to note from Harry Binswanger  Fri, 17 Dec
2004 22:37:47 -0500

> How do you reset [VA$ER] to 0?

You can't. Not in Xy4, in any case. Way back when, Robert
discovered a way to do it in Xy3, by concatenating a VA with a S/G
-- a nonsensical operation that bombs in Xy3; to avoid crashing your
program, you push it down into a SUbroutine. In pseudo code, it
looks like this:

+>NO >

Here's the real code:

XPLeNCODE v2.0
b-gin [UNTITLED]
{<}SU01,{<}SV02,{>}{<}SX02,{<}IS02{>}+{<}VABT{>}{>}[NO_]{>}{<
}GT01{>}
-nd
XPLeNCODE

As I recall, that worked nicely (fast, and no error beep) in Xy3.
But it doesn't work in Xy4; (there, it's a valid concatenation).
Nothing works in 4 -- at least, nothing we've been able to find.
The best you can do is set VA$ER to a known value, e.g., 11 (There
is no command on command line) with BX Q2 , or 12 (Command is not
recognized) with, e.g., BX zQ2 , or 76 (Math function requires equal
sign) with, e.g., BX 0Q2 , or.... you get the idea. Make sure that
Error Suppression is enabled, to avoid an error beep.

> Tim Baehr once said that it could be done by the ES command
> without any number following it, but that didn't work.

BX esQ2 is the equivalent of BX es 0Q2 . It disables Error
Suppression. It has no effect on VA$ER.

If you can find a way to zero out VA$ER, Harry, you'll go down in
XyHistory. It's a gap that XPLers have been trying to fill from Day
One.

--
Carl Distefano
cld@xxxxxxxx