Re: [CAD_CAM_EDM_DRO] Machine security and safety

Hi Chris,

I might add that early Gcode was often on paper tape (with a few
different formats), and some formats had/used the parity bit.

One of my first "consulting" jobs was an editor for reading/writing
paper tapes in various formats. The program ran on a (then new) "TRS
80" computer, and my CPM system.

Alan KM6VV

ccs@... wrote:

>
> > Speaking of which, does anyone know who came up with "Gcode" and why they
> > chose not to include some kind of safety checksum in the commands? I'd be
> > more concerned about a garbled step command than someone 'hacking' into the
> > machine...
>
> Well, checksums are hard for people to calculate, and it is in fact
> very usefull that someone can grab just about any text editor and
> write gcode by hand. So I think that there is a good reason that the
> format itself does not have a checksum. But it could be done as an
> add on if you want - it would be easy to write tools to add in and
> strip out the checksum from files for compatability with the standard.
> <SNIP>
>
> Chris