From: saksa@hpldola.HP.COM (Tom Saksa)
Date: Mon, 6 May 1991 17:40:02 GMT
Subject: Re: Gerber photoplotter format
Message-ID: <10960038@hpldola.HP.COM>
Organization: HP Elec. Design Opr. -ColoSpgs
Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!sdd.hp.com!hp-col!hpldola!saksa
Newsgroups: sci.electronics
References: <30063@dime.cs.umass.edu>

> I would appreciate if somebody could give me some clue as to the 
> translation of Gerber photoplotter formats. So far, I have deduced the
> obvious:
> XiimmmYiimmmDnn    move to position (ii.mmm,ii.mmm) and use aperture
>                   nn (D01: open shutter, D02: close shutter, D03:
>                   flash)
> M02                concludes file
> D10-D26,D70-D73    circular or rectangular shapes
> *                  terminate record
> G01                ?
> G90                ?
> G54                ?

G01   Linear Interpolation (Draw straight lines)  This command is
needed to switch back to line drawing mode after another G
command.  Some programs output a G01 before every move command.
This is not needed, but it does not hurt.  Note: some Gerber plotters
support circular, parabolic, or cubic interpolation, G02, G06, and 
G07.  They are not very common though.

G54   Used before the aperture select commands D10-D26,D70-D73.

Note:  On some plotter controlers it is not neccesary to include
a G54 before an aperture command.  Be careful, because many
Gerber commands do not work on all gerber plotter controlers.

G90   I have not seen this one.  Call Gerber and ask!  (203) 644 1551


    No Gaurantee on correctness of this info.