Re: Is this an unreported bug in EMC? (rant)

[Ray Henry <rehenry-at-up.net>]

Clint 

It is probably a good idea to resist the two axis Keyboard impulse.  I did
a little study a while back because I thought a keyboard emulator would be
a good way to make an auxiliary control panel. The keyboard sends 11 bits
when a key is pressed and 11 more when it is released.  These bits are an
inverted and muddled asc code and they vary from one IBM "standard" to the
next.  

Whomever thought this up is right up there with the creators of the y2k
short sightedness. They never intended for two keys to be pressed at the
same time. (we don't do that typing text)  They had to add special routines
for shift and the other modifiers.  So one press followed by another causes
the end codes to get mixed.  

Add to this the fact that the keyboard interpreter chip on the mb dumps
stuff it doesn't understand and requests a re-send and you have the makings
of a whole disaster.

We could pretty easily cook up a tkemc that had an array of buttons that
would let you press one and get two motions. Perhaps a popup. Some games do
this with the num pad.  I'm playing with this for a touch screen (also a
serial imput device) but decided quite a while ago, after a nasty crash,
that I would abandon the keyboard for machine control.  

I wrote stkemc (a tcltk exercise) with a single row of buttons that I
access with the mouse.  It's a bit slower but I don't make mistakes. This
also means that I use mdi for those long multi axis moves. (g0 x21 y8 z-5) 

IMO the stock emc gui's really aren't intended for hard core shop floor
work.  They are optimized for the flexibility and detail that the emc group
needs to develop and test emc itself.  One of the first tasks of the
emc_gui committee, (see other rant) beyond bug fixes, should be the
specification and development of some shop hardened hmi's that take account
of the ways operators make their production quantities and maintenence folk
check out, service, and tune machines.

Ray


At 04:57 PM 1/21/2000 -0500, Clint wrote:
<snip>
>> The TkEmc user interface, I'm pretty sure, uses entirely different
>> methods, and does not suffer from this problem. (but it has
>> others).
>> 
>> Jon
>
>Well,  I'm using tkemc and it still does it on my machine...  I can
>resist the two axis impulse!!!