Programming systems for other manufacturing processes, such
as milling, turning, flame cutting and others already existed for some time,
mostly to be used on large mainframe computers. The first systems suitable for
wire EDM appeared on the market only in the early 70s. These systems did not
need to be as sophisticated as the others mentioned above, there was no
technology, feeds and tool changes to be taken into account. Furthermore, all
movements were restricted to the two main axes, normally named X and Y. This
means, that the available programming systems were requiring more information as
input data as needed for wire EDM, and also creating unnecessary output.
The chronology in which the first systems appeared and were adopted (if at all) at AGIE is very difficult to reconstruct, the company took a long time to decide what kind of programming support had to be offered to the final customer.
With the introduction of desktop computers, which were
powerful enough to shoulder this kind of application, a completely new marked
opened up for the manufacturers of programming systems.
The first computer making its appearance and suited for such an application was most likely the HP9830 of Hewlett-Packard. This was a machine which could be programmed in the programming language BASIC and which had a footprint not much larger than a typewriter. In its standard version it was delivered with "incredible" 4 Kbytes of memory available to the user, for a market price of US$ 5'975.--. This base unit could be extended, with the appropriate printed circuit board, to a maximum of 8 Kbytes, adding another US$ 1'475.-- to the price tag. At the left hand side of the computer there was a small compartment which could accommodate a number of ROMs, which were pre-programmed for specific calculations, such as creating the output for a plotter, the treatment of string variables, the output of data to other peripherals, etc.. Each of these ROMs had to be purchased separately and plugged in if necessary for the application. In the standard configuration which could be used for the programming of NC-controlled machine tools, the three above mentioned ROMs, for a unit price of US$ 485.-- had to be included, as well as a printer (shown on top of the computer in the image shown, US$ 2'975.--), a pen plotter (US$ 2'675.--), a paper tape reader (US$ 1'470.--) and a paper tape puncher (from FACIT, price unknown) had to be purchased, for total of approximately US$ 12'000.--, not including the paper tape puncher and the necessary software.
As software, a product of a French developer was used, initially designed for milling applications, and named ELAN-30. This software enabled the user for the first time to define the geometrical elements and the sequence in which they had to be traveled along, without having to care about the computation of intersection and tangency points. Based on the computed data, a punched paper tape was automatically produced, containing all the relevant information. A tape cassette deck was incorporated in the computer, but the cassette had to be inserted in the drive during computation, as several segments of the software had to be continuously swapped because of the restricted memory. This paper tape obviously contained a lot of data not needed for wire EDM, such as tool changes, feed rates and movements in the Z-direction. This data was always punched, even if completely ignored for the subsequent processing.
During a second run on the computer, the punched tape was read again, to be used with a special postprocessor, transforming the general data into information needed by the AGIECUT machines. The first of these postprocessors was actually developed for the DEM-25, the wire EDM model which followed to the DEM-15, the data needed by the first model seemed to complex for the French developer to produce a usable postprocessor. This first postprocessor was developed as a co-production between the French company and AGIE, in order to acquire enough knowledge to develop any further postprocessors in house at AGIE.
In the programming department of AGIE the second postprocessor, this time for the DEM-15, was developed, initially only for output in the codes ISO and EIA, later also for the AGIECODE. In a second release, the postprocessor for this machine also included a very sophisticated method to approximate the fractions of degrees for circular arcs. By using elliptical arcs rather than circular arcs, the fractions of degrees could be approximated with a much higher accuracy. The still remaining tiny errors were accumulated at every calculation, to be taken into account in the following instance, bringing the overall accuracy to a never attained final result.
The first computing centers
At some time in the same period, the first computing centers,
with its huge machines, tape drives, and air-conditioned rooms with double
floors opened, using a variety of computer models and brands. The first of these
centers, equipped with hard and software for the programming of NC-controlled
machine tools was located in the vicinity of Zurich, quite a distance from
Losone and Ticino, were such centers opened only much later. The geometry and
the machining sequences for the parts to be programmed had to be encoded in the
application software APT (Automatically Programmed Tools), or its clones. This
data was written down on specially created forms, to be punched into 80 column
punched cards to be fed into the computer. The machines to punch the cards were
available at AGIE for other applications, but always occupied for internal
needs, therefore the cards had to be punched on the units available at the
Packing all the filled in forms into a briefcase, one had to travel to Zurich, to first punch the cards. In the evenings, when the computer was not used for other applications and the APT application could be loaded, the punched cards were fed into the machine. The first run invariably resulted in a program stop, caused by a punching or definition error. The error message was printed out and had to analyzed, so that the erroneous punched cards could be corrected, before starting a second run. The application software was still quite primitive, and stopped the process whenever the first error was encountered. This means, that the single errors had to be eliminated one by one, until the postprocessor could be executed without any glitch. This resulted in a paper tape, punched on a high speed puncher, put away with all the other successfully computed programs, before boarding the train again to return to Losone.
The first time-sharing systems
A short time after this quite cumbersome solution, the first
computing centers offering computing possibilities at a distance opened,
enabling the users to access the computing power via a suitable terminal. Such a
terminal was therefore acquired and the personnel was trained in its operations.
Rather than punched cards, a paper tape was now used as data carrier, obviously
punched in the off-line mode, to save on expensive telephone connections.
To enable the communication with the remote computer, a modem had to be rented as well from the local telecom company. The external dimensions of that unit corresponded approximately to those of a desktop computer used today, with the "incredible" transmission speed of 300 Baud, a terribly slow speed, compared to the rates available nowadays. In order to guarantee a faultless transmission of the data to and from the remote computer, a "clean" telephone line was needed, not passing through a switchboard, always causing some parasites and disturbances.
When the input program was punched on the tape, the communication with the "time sharing" computer could be established, to transmit the data of the program to be computed and to start the first run through the application software. Here as well, the processing normally stopped at the first error that was encountered, After some time, minor changes could be applied to the APT software, enabling it to pass on after an error, delivering the appropriate message, to be evaluated later by the programmer. These corrections could then be executed at the desk, to start a new computer run once the new tape was ready.
The AGIPAC system
A company in England, which had acquired a DEM-15 for the
tool room, was active in the field of manufacturing computers. They decided to
develop their own version of a programming system, named AGIPAC (not to be
confused with any AGIE product), working in a dialog with the programmer.
Here as well, the programmer had to be connected with the computer via a telephone line, to receive the questions and send the answers to the remote computer, unfortunately located in England, increasing the cost of a program generated by these means by a considerable amount, due to the high telephone costs charged in those times.
This AGIPAC system was very short-lived, mostly because there were very few computing centers which were equipped with the appropriate computer model, and also available for remote access.
After these first developments, innumerable other systems
followed, to enumerate them all would be virtually impossible.
In 1976, Hewlett-Packard introduced the new HP-9825, a desktop computer, not larger than a typewriter, including a keyboard, display, special cassette deck and a thermo printer. The programming language was one developed by HP, named HPL and including features normally only available only on much larger systems. AGIE first acquired one such computer, costing at that time US$ 5'900.-- without the necessary peripherals, consisting of a pen plotter and a paper tape puncher. This computer was made available to a department at the Swiss Technical University (ETH) in Zurich, where a new programming system for the wire EDM machines had to be developed.
The HP-9825 had a special feature, the so-called interrupt function, enabling the computer to branch to a separate operation, when a determined signal was received. The intention was to use the computer for the programming of a new shape, whilst transferring available NC-code to the machine whenever it was idle. This resulted in a continuous action on one of the special function keys (F9) of the computer, before any input could be made. This solution was later abandoned, as very few users were willing to place the computer close enough to the machine, accepting the noisy and unfriendly environment of the tool room.
The programming system which resulted from this development was named LAMA-25, following a certain line names adopted by the head of this development at the ETH. This product, later along with its developer, was adopted by AGIE as its standard package, offered and sold along with many of the wire EDM units sold worldwide.