3 ms·
Well I've been doing computerized gas analysis since dirt was rocks and only the rare laboratories with mainframes could do it. Before the first benchtop data
by fuzzfactor 5y ago
Well I've been doing computerized gas analysis since dirt was rocks and only the rare laboratories with mainframes could do it.
Before the first benchtop data systems came along you had to evaluate the curves from the graph paper yourself and then calculate numerical results by hand. A single-point report like CO2 content alone is quite easy & quick manually, but when you have dozens of hydrocarbons on the same graph that all need to be calculated in parallel it was not so quick and more prone to error.
Programmable calculators could then be used to save time on some of the purely numerical work for the high-data runs, and this is about like what would become the final part of the built-in workflow for these early application-specific computerized gas workstations.
Offices didn't have PCs yet, just typewriters, copiers, filing cabinets and simple calculators.
For laboratories the built-in gas report printers were leapfrogging technology with each generation, the inkjet first appeared in a HP model for the instrument lab before they began to apply it to office equipment.
The evolution has been interesting.
One particular series of late 1970's design benchtop data system was multi-user and multi-tasking way before Windows. Like others it took in the raw analog signal (still do but they're "black box" interfaces connected to PC's for further calculation now) from the benchtop gas analyzer in real time and produced digital data from the curves on the graph. This electronically accomplished that first manual procedure of measuring the curve to begin with.
From that point on it's all calculation.
Each gas run was autosaved in memory as a file having an automatically-assigned file number, no more than 3 digits. There was no way anybody had enough memory to record the entire analog signal at the time so this was just the key geometric features in digital form.
There was no file system.
Today on PCs the entire analog gas signal is recorded to HDD in digital format routinely. And people still lose files all the time, don't ask me how I know.
But for that antique data system there was no storage other than memory absolutely required, many bare-bones consoles were issued without the optional micro-cassette tape drive. The tape was quite slow and best for long-term storage or disaster recovery. An optional COM port became available years later which was faster, but there was no workflow change for most users. A great deal of fairly advanced work could be accomplished by many without need for any storage device I/O over a period of years. Just a one-page printout about each gas destined for the physical filing cabinet.
You never were supposed to turn the console off. Except whenever you wanted to! The major use case is 24/7 so there were expensive battery backup units to protect from short- or long-term power failures, which only preserved the memory. If the power failed the battery kept everything the same and you only lost a gas run if it was in progress and had not been saved in memory.
But you could also power down the console from the main switch any time and its high-power-consuming hardware, processor, and power-supply would go cold. Like when you're done for the day, the gas runs are over, and you were finished sitting at the console. The memory alone would still be powered by the battery backup unit without depleteing the battery at all unless the backup unit itself lost power. Under backup power you could also change any circuit board other than the dedicated memory PCB, including the main power supply, and it would power back up with the memory intact.
The OS was immutable and in ROM where it should be.
Also the default OS performance upon cold power-up was adequate for many simple gas tests without need for user programs or reference data files to be loaded beforehand. For many operators a few minutes of manual parameter entry gave full disaster recovery. So those guys didn't even need the expensive batteries, tapes or COM port. It was basically application-specific enough for the simple stuff already.
You could then extend that with optional user programs to more complex automation & calculations but only up to the limitations of memory.
User programs ended up as file numbers too so you were your own file system.
And to just get a truly worthwhile file listing, you had to write your own program.
Glad there were only 3 digits.
These things did achieve nearly zero show-stoppers per year on average, unlike modern PC systems which are in the handfuls at minumum and dozens for many operators on average.
There was no booting, the OS ran from ROM and the memory was accessed as needed from there. Optional storage devices were only needed for user items, the OS did not require any files from storage, and only one file present by default in memory. Simply its own memory work area.