HP-75 plots whales on HP-7220C plotter

Here we see an HP-75 (bottom right) plotting whales of various sizes on an HP-7220C plotter.

The HP-7220C plotter has a serial (RS-232) interface which means that the HP-75 cannot be connected directly to the plotter, but uses an HP-IL to RS-232 converter (HP-82164A).

The HP-82164A needs to be configured in order to drive the HP-7220A plotter, which means that you need either the HP-75 I/O ROM or the HPILCMD lex file (this is available at http://www.series80.org/Misc/HPILCMD.SWP, but please read the instructions at http://www.series80.org/Misc/HPILCMD.txt).

The whale image is a close replica of the logo of the Kunst Museum in Wolfsburg, Germany. By using mostly straight lines, the logo can be drawn fairly easily on the plotter. The only "tricky" point is the eye of the whale, which is a circle (and you can see that the plotter slows down in order to draw it).

There is a single dataset which defines one A3 sized whale. This is then scaled in order to draw each whale on the plotter.

A bounding box is defined using the (HPGL) IP command (IP: Input P1 and P2 scaling points). Point P1 is the low-left point of the bounding box, while P2 is the upper right. The scale command (SC) is used to define the coordinate system inside the bounding box. Note that the size of the bounding box defines the size of the whale - all whales are drawn with the same SC parameters.

So to create the 21 whales, I also created another dataset with the P1 and P2 points for the bounding box of each whale.

For each whale I draw the outline as a single polygon and then use open polygons to draw the remaining lines (UPDATE, I forgot one fin, so this is drawn separately). As I mentioned above, the eye is a circle drawn using the circle command (CI).

Information on the Hewlett Packard Series 80 computers may be found at www.series80.org.

Видео HP-75 plots whales on HP-7220C plotter канала vp