Amiga and HP plotter

[gurth]

There are plotter definition files in IntroCAD that I need to select and load before plotting for the 1st time. There is a generic hpgl file and one for the HP 7470a (an A4 plotter). They are identical bar the x / y sizes as mine is A3 sized so for the sake of ease I have been using a generic definition file.

They define the page size and map the HPGL commands to what IntoCAD uses internally I guess. There is a section in the manual describing how to define your own if required - I have not as of yet.

An contents of the generic hpgl file:

HPGL
1016 1016 10. 8. !x_units_per_inch, y_units_per_inch, x_inches, y_inches
!DF;<0x1b>.N;19:<0x1b>.I81;;17:
!	init
! !				sep
!;!				term
!SP!				selectpen
!SP!				storepen
!PU!				penup
!PD!				pendn
!LT!				linetype
!!				close

The <0x1b> I have added as it is an ASCI control character for ESC, they are there in the file but not clear when I have been viewing them in ED on the Amiga.

The start of the HPGL file I outputted from the Amiga and played out via my Mac had the same "setup" on the first line and prompted me to dig a little deeper as the commands did not look to be traditional HPGL as I knew it. Start of outputted file from Amiga that I transferred to the Mac earlier:

DF;.N;19:.I81;;17:
 PU; SP1 ; PU 5758 7282; PD 5589 7282 5419 7113 5419.... [and off it draws...]

I bought the manuals for the plotter the other day so I have been cross-checking them as I have gone along which brought me to these "control" commands, all using ESC.[something]:



Here it is talking about the buffer filling up quicker that the plotter can handle and the computer overshooting despite the plotter calling for a halt - the delay in receiving a plot message and sending a message back to the Amiga to say stop - too late the Amiga has already sent another message in the meantime.

Which felt like the scenario I was seeing. I could plot 1 circle fine, 2 circles fine, 3 circles and !

Final output once I had set the "intercharacter delay" parameter:

!DF;<0x1b>.N100;19:<0x1b>.I81;;17:

Note the <0x1b>.N100;19 vs. <0x1b>.N;19:

The ESC.N command - aka <0x1b>.N

The instruction is used to specify an intercharacter delay 
in all handshake modes, the immediate response string for
enquire/acknowledge handshake, or Xoff trigger character(s)
for the Xon-Xoff handshake.

Anyhow - it all works A500 to HP Plotter just as god intended:

[gurth]

I also managed to have NComm and Terminus connect to the plotter. It was far from perfect as I could not see what I was typing in but I could select a pen (SP1) and query for error codes. It would have been nicer if I could have echo what I typed. Sure it is possible if I spend a little more time setting up.

IntroCAD manual talks of scripting and Arexx command which could come in handle for my generative art goal.

Next step is to install ProVector and try that. Wish me luck!

[gurth]

Aegis Draw Looks to support plotters too.

[gurth]

Aegis Draw 2000 installed on Workbench 1.3.
Plotting dumps a file to disk oh well I will have to learn a way to pump this to the plotter from the Amiga by hand. I can always copy the file back to my Mac if needs be...

ProVector 2.0 installed on Workbench 1.3.
Very similar experience to IntroCAD, starts to plot but then stops and the error light flashes.

Could do with a manual for ProVector anyone?

Sure there is a config file somewhere but the hpgl file I pick to selecting a plotter looks to be a binary - not much I can read in a text editor.

[gurth]

Found a manual for ProVector online.

Plotting succesful

[gurth]

and I have learnt I can pump the HPGL output file from Aegris Draw to the plotter like so:

COPY DRAWPLOTDUMP TO SER:

Where DRAWPLOTDUMP is the name of the file Aegris Draw outputs when I ask it to plot:

It draws the grid oddly?!



SR71

[gurth]

Simples. If you turn off the grid from the view before you plot it is excluded too from the file.

[redblade]

Thanks for the scanned chapters on scripting and ARexx for IntroCAD, as I was having trouble trying to draw simple shapes because of the accuracy.

Glad you got your plotter working.

What software do you prefer AegisDraw or IntroCAD?

The SR71 seemed to be standard thing for the CAD software in the 80s

[gurth]

I have not had chance to play with either in truth as so much time has been spent on getting this far (sourcing, transferring, unarchiving files between my Mac and Amiga - I am sure we all know these woes).

AegisDraw feels a tighter more professional application; windowed tools, multiple files open simultaneously. There is a PCB example drawing that looks every much as something AutoCAD could do in 1988.

IntroCAD feels simpler and more approachable from the start. I have a hard copy of the manual and it appears to support scripting (thank you for showing me) so this might be where I start my adventure.