原创 How it used to be: Fan-fold paper and ASCII art

Around the late 1970s to early 1980s, the printers we used were dot-matrix or line printers of the continuous feed variety. The way I remember this is that the printer was mounted on a stand with a box of fan-fold paper sitting on the floor feeding up into the printer (I haven't found a photo of such a printer, but someone pointed me at an image of a A DEC LA36 DECwriter II Terminal, which looks sort of similar – I've added this image later in this column).

When I say "fan-fold" paper (also written as "fanfold" and "fan fold"), I'm referring to a continuous strip of paper that was folded back and forth in a zigzag manner. The first image below shows a short piece of fan-fold paper containing only a few segments. In reality, a new box would be about 8" thick containing hundreds of segments (maybe thicker; my memory fails me; does anyone recall the nitty-gritty details?).

As I recall, fan-fold paper was available in a variety of different widths. The examples shown below are narrower than the type we used. I think the paper we used was about 18 inches wide and accommodated about 132 characters (the characters were monospaced [fixed width] courier-type font).

On either side of the fan-fold paper were sprocket holes, which were used to feed the paper through the printer. Also, the folds in the paper were accompanied by tiny perforations, which made it easy to separate the sheets. Having said this, we rarely separated our printouts into individual sheets; all we did was separate one print job from another. Engineers typically had numerous binders of fan-fold paper containing computer program printouts sitting on their desks.

A small piece of fan-fold paper

An example computer program printout on fan-fold paper in a binder

A DEC LA36 DECwriter II Terminal

One problem with this scheme was that if several people dispatched print jobs to the printer around the same time, you could end up with a monstrous pile of fan-fold paper on the floor. It could be difficult to determine where one listing ended and the next started. In order to get around this, the system manager typically set things up such that the first page of each print job contained a big banner formed out of ASCII characters. All of which leads us into ASCII art...

These days we are used to high-resolution graphics screens and high-resolution color printers. We are also used to having sophisticated graphics capabilities allowing us to draw (and print) lines and shapes and suchlike. We simply did not have this sort of thing back in the 1960s, 1970s, and 1980s, but engineers always seem to find ways to work around problems like this...

One solution was to use text characters to represent images. The American Standard Code for Information Interchange (ASCII) was an 8bit code that was first defined in 1963. In addition to various control characters, ASCII defines 95 printable characters (or 96 if you count a space as a printable character).

ASCII art ranged in complexity. Some of the simplest examples just used a few characters (like 'X' and '*' and '/' and '\') to create outline-type images as shown in the Snoopy example below:

ASCII Snoopy

More complex examples used the fact that the number and position of the dots forming each character mean that different characters are perceived as having different levels of gray when seen from a distance and in the context of surrounding characters. This effect can be enhanced by over-printing one character with another. The result could be very sophisticated as shown in the Cat example below:

ASCII Cat

Actually, it's difficult to convey just how clever these images could be. It's also difficult to convey how large they could be, because it was not uncommon to tape a number of strips of fan-fold paper together to make a larger image. In fact, I remember one guy from around 1990 who had an incredibly detailed ASCII art picture of the moon on his wall that must have been 8 x 8 feet (convert to m) square.

On the shelf in my office I have a pile of punched cards and a couple of roles of paper tape. I was thinking that I had probably missed my chance to get some fan-fold paper ... but I just discovered that they still sell it at Office Max (a few weeks ago I discovered that Office Max also sell old-fashioned carbon paper, which came in really useful for a little project I was working on).

Last but not least, and on the off-chance you are interested, I just found an online ASCII art generator at www.glassgiant.com/ascii. This allows you to upload an image from your computer which it then converts into ASCII art for you.