Classic Computer Magazine Archive CREATIVE COMPUTING VOL. 10, NO. 3 / MARCH 1984 / PAGE 202

Creating a letterhead with your daisywheel printer. Thom Hogan.

Creating A Letterhead With Your Daisywheel Printer

If you own a daisywheel printer such as a Diablo, Qume, or NEC, you may have noticed somewhare in the specifications that your printed is capable of generating graphics. If you were like me, you probably filed that information in the back of your brain and commenced to use your printer for listings and documents.

Several years ago I bought one of the first Diablo 630 printers as they were introduced. This letter-quality machine prints charqacters using a standard daisywheel element (like a Selectric "golf ballH only flat) at a rate of 45 characters per second.

Since I am a busy author, the Diablo 630 has more than proven its worth; I estimate that I have run more than 300,000 pages through the printer without experiencing a single problem.

Recently I found myself with a bit of extra time on my hands, and for some reason the notion of daisywheel graphics came popping out of my random thoughts. I decided to see if I could make the Diablo do something simple, like print my name in big letters at the top of the page, simulating a simple letterhead. By the time you finish reading this article, you, too, should be able to create simple graphics on your daisywheel printer.

Some Background

Before getting to the actual process of creating graphics on a daisywheel printer like the Diablo 630, we need to be sure that we are all working from the same base of information. So, first some background information you will need to know.

Diablo was the first to introduce a daisywheel printer. The daisywheel looks much like a daisy; the spokes that hold the characters to be printed are held together in a flat carrier that looks a bit like a flower with letters on each petal.

The principle of printing with a daisywheel is simple: rotate the spokes of the daisywheel until the proper character is on top, then hit the spoke so that it impacts the paper (through the ribbon) with a small metal hammer.

In addition to producing a machine to print characters like a typewriter does, Diablo decided to make the printing of the daisywheel more flexible. They did this by making the mechanism that moves the daisywheel back and forth across the paper capable of moving in extremely small increments. What this means is that the Diablo is capable of doing print in elite, pica, or any other spacing of characters across the page.

In addition to offering this flexibility in the horizontal direction, Diablo made it so that the printer was capable of a similar move in the vertical direction, meaning that characters can be printed six lines to an inch, or any other number the user dictates.

Other daisywheel printers followed the Diablo. Most notable are the Qume Sprint series and the NEC Spinwriters (although the NEC uses a different typing element, called a Thimble, its design is similar to that of the Diablo). Recently, other daisywheel printers have appeared, including one from Radio Shack manufactured by Ricoh, a Japanese company. With the exception of the low-cost typewriter-based printers such as the Smith Corona TP1 and the Brother, the techniques desribed in this article should work with most daisywheel printers.

Now let's be more specific about the Diablo printing abilities.

In the horizontal direction, the Diablo (and others) is capable of moving the printhead 1/120th of an inch at a time. That is right, you could print 120 characters an inch if you so desired, although I can't imagine what the font that would do that would look like, since it would be unbelievably small. The reason Diablo built this precise horizontal motion into the printer was to allow for proportional and incremental spacing, where each character is separated by a varying amount of white space to make the right margin line up.

In the vertical direction the Diablo can move the print mechanism in increments of 1/48th of an inch. Thus, the maximum density of information you can print using a Diablo 630 is 120 X 48 in a square inch.

As for graphics, the normal method of obtaining them is to print a period (dot), move the print mechanism in the direction and amount you desire, then print another period. If you do this correctly, you can create graphs, drawings, and even different type fonts.

Obviously, there is some limit to the ability of the Diablo when used as a graphic printer. First, there is the speed penalty: remember that the 630 prints at 45 characters per second, which means that graphics will appear at 45 dots per second. If you have a great deal of drawing to do, it will take time. Second, you will find that, even with a good tractor feed, the resolution of the printer (ability to place a dot accurately) is more accurate in the horizontal direction than in the vertical. Part of his is the disparity in dot densities (48 versus 120), but much more is simply that the paper is kept steadier on the horizontal axis than on the vertical.

Getting Started

Having looked up all the relevant information in the Diablo 630 manual, I began searching for the simplest method of making use of the Diablo features.

There is an escape sequence--a group of characters that begins with an escape--that is used to tell the printer to move its print mechanism. With these commands you can move the printing in any direction you want, in the increments I have described above.

The more I looked at this method of telling the printer what I wanted to do, the more I knew there had to be an easier way. Fortunately, I was right; if you have a sophisticated word processor, there is an easier way.

WordStar, the word processor I use, has so-called dot commands that allow you to reset the way the printer works. For instance, a .LH 8 in a text file means that WordStar should tell the printer to move 8/48ths of an inch each time a linefeed is encountered. Likewise, a .CW 12 tells WordStar to move the Diablo to move 12/120ths of an inch each time a character is printed.

Bear in mind that these commands work only if you have correctly installed WordStar for your daisywheel printer. If you are not sure if your printer has been installed for the capabilities of the daisywheel, consult your manual or the dealer who sold you your equipment.

Since I wanted to use dots to print out graphics, and since WordStar could do the control of the printer in the manner I wanted it to, I began to experiment. I decided that first I would try to print out a large block, about the size I wanted the characters in my name to be printed. Figure 1 shows the WordStar file with which I began.

I made the box eight characters wide by ten deep since that is the same matrix used in the character set in my computer; I figured that I could start by using the characters already on the computer and then improve upon them. Note that the periods that make up the information I want printed cannot start in column 1, since WordStar interprets a period in the first column as a command not information to print.

Those of you with other word processors will have to look up in your manual to learn how to change the horizontal and vertical printing parameters. Some, like Perfect Writer, do not allow you to print graphics in the manner I describe for WordStar.

The block came out well, although it was a little smaller than I had imagined. I widened it to 16 dots wide to compensate for the fact that the horizontal motion is smaller than the vergical, and again printed out my result.

Having decided upon the size of the graphic I wanted to create, I began working on the design. Since I wanted primarily to print my name in large letters, as on a letterhead, I began designing my font. The letter A, for instance, appeared as in Figure 2 when I was editing it in WordStar:

I next tried printing it out; the result can be seen in Figure 3a. A little small, I decided. Instead of redoing the character, however, I simply changed the .cw 1 to a .cw 2. The result of this change can be seen in Figure 3b, where the character is twice as wide as before. I decided to try one more idea, making the line height 2/48ths instead of 1/48th. This result is seen in Figure 3c. The nice horizontal stripes that form in this version are suggestive of the latest look in logos.

The next step was to create my complete alphabet. You can see the matrix and the results in Figure 4.

Putting It Together

Finally, I was ready to try my hand at creating my letterhead. I had a complete set of letters and numbers in a file I called LARGE.FNT, and each individual letter in its own file, such as A.FNT, B.FNT, and so on. $yBy using the block read command and the column block move command, I was able to read in the letter I needed next, then move it to the position on the page at which I wanted it. Since WordStar has horizontal scrolling up to 250 characters, I could theoretically put almost 20 of my large characters across the page without having WordStar begin to wrap lines around so I couldn't easily see the placement (Note: make your right margin 250 when editing your graphics, or you will end up at some point fighting the attempts of WordStar to put all those periods into a incrementally spaced line, i.e., WordStar attempts to split long lines into shorter, formatted ones).

After getting my characters correctly placed, the next step was to print my address in normal text. After much experimentation, I discovered the best way to do this was to put the line of text I wanted printed normally at the end of the graphics, then use the superscript command to raise it into the position I desired. The resulting file (with a dummy address) can be seen in Figure 5.

One cautionary note: If you are using the graphics for letterhead, you will have to do a bit of experimenting to establish where the end of the page should be. WordStar sets the end of page by counting lines, and we have a bunch of lines that are only 1/48th of an inch apart, while others are spaced at 8/48ths. Generally, the manner in which I determined my proper page length was to do the following:

1. Measure the vertical size of my graphic.

2. Write my text, leaving the amount of space blank I determined in step one.

3. Find where WordStar split the page.

4. Add my graphic at the top of the text.

5. Then reset the page length command on the first page so that the page break is where WordStar put it in step 3. Make sure to reset the page break to the default beginning with page 2.

Wrapping It Up

That is all there is to it. With the method I have outlined above, you should be able to create your own large characters, drawings, and other graphic material to place at the top of your letterhead. I have tested this with Diablo, Qume, and NEC printers. It should also work with the Radio Shack, Ricoh, and other incremental-spacing daisywheel printers.

Photo: Figure 1.

Photo: Figure 2.

Photo: Figure 3a.; Figure 3b.; Figure 3c.

Photo: Figure 4.

Photo: Figure 5.