Wang paper tape format?
rickb at bensene.com
Sat Jun 25 11:47:02 CDT 2005
> I have some paper tapes that I'm trying to read and I have
> good reason to believe they are from a Wang machine of some type.
The first devices that Wang Laboratories made that utilized punched paper
tape were numerical control (NC) units for vertical machining centers, such
as drills, mills, etc The control units read EIA-standard punched tape (not
ASCII). The EIA code is an 8-level code. The 8th bit marks "End of Block".
One bit (either 6 or 7, I can't remember) indicated upper or lower case.
Another bit (again either 6 or 7) encoded odd parity. Five bits were used to
encode the character set, bits 1 through 5.
Each numerical control command consisted of codes designated by a single
letter, followed by a numeric argument. For example, to move the table to
X,Y coordinates of 1.075 and -0.800 inches, the command might be:
There were various G codes for functions such as moving the table, changing
spindle speed, lowering and raising the drill or cutter, pausing for
operator intervention, etc. As control units became more capable, other G
codes were added for doing things like autmatically machining arcs,
performing threading operations, automatic tool changing, etc.
At the time (Wang got in the NC business in the late 1950's, mainly due to
contract work for Warner Swasey, a large metalworking machine manufacturer),
the most common device for preparing punched tape programs for numerical
control units was the Friden Flexowriter. The Flexowriter line had many
different models, including units that punched custom codes (for early
computer consoles on the likes MINIAC, LGP-20/21, early MONROBOT etc.), EIA,
and Baudot (5-level tape). The original Flexowriter design wasn't capable
of ASCII. The EIA-code Flexowriter is the most common.
To diversify business in the early '60's, Wang took a contract to build a
typesetting machine, called Linasec. This machine was driven by punched
tape. These machines were used at newspaper publishers for setting the type
for the printing of the newspaper pages. I have no information on the
structure of the data encoded on the punched tape for submittal to these
machines, but it could be that you have a tape that was prepared for a
Linasec, in which case, it's quite a rarity. The whole story of Linasec is
worthy of an article in itself, but suffice it to say that due to the
outcome of the Linasec project, Wang Labs found it necessary to develop
another primary product base, which spawned the beginning of the calculator
Wang also used punched tape units in their calculator line. Peripheral
devices were available for Wang's LOCI-2 calculator that allowed the machine
to read and punch tape, as well as for many other later Wang calculators.
In the calculator arena, all of the devices responded to the ASCII code.
As the calculator business became far too competitive, Wang entered the word
processing marketplace, with the 1200-series word processor. These machines
were based on the "CPU" design of the 700 and 600-series calculators, but
with different microcode to perform basic word-processing applications.
These machines utilized a modified IBM selectric typewriter for
input/output, but also had a separate punched paper tape reader/punch. My
memory fails as to whether EIA or ASCII was used on the 1200-series. Later
Wang word processing systems changed over to using magnetic tape(audio
cassette form factor with specialized tape formulations for storing digital
data) for storing documents. It could be that the tape you have is for a
1200-series word processor -- again, a rather rare find. The 1200-series
didn't last very long, as it was sabotaged by IBM, which failed to include
an important spring in the Selectrics provided to Wang, which made the
machines type unreliably.
With all that said (I hope the story is interesting), my guess is that you
have an EIA encoded tape, because of the single punch in the 8th bit, which
was indicative of the EIA code. If it isn't EIA, then it might be a custom
variation of the EIA code specifically for the Linasec or 1200-series
machine, in which case, using EIA as a base may help in determining what the
tape says. Typesetting and word-processing, by their nature (with various
fonts and sizes, type fonts, justification modes, etc.), may have required
extending or changing the encoding on the tape, or developing a completely
new type of code to represent the various typesetting functions in a form
most easily digested by the relatively simple electronics (all discrete
diode-transistor logic) that Linasec was built from. Given the notation of
"pages", it's not likely to be a numerical control tape.
I'm curious, what led you to the conclusion that the tape was prepared or
generated for/on Wang equipment?
Best to all,
The Old Calcualtor Web Museum
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