Your point seems to be that you are making pointless points.
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- Thread starter OxiaUK
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Buzzer in series with LEDs is a bit dubious. I'd put a resistor between +12 and the switches to set the LED current, and then a transistor to turn on the buzzer:
This still suffers from reduced brightness when more than one switch is on; you can largely fix that with more resistors.
Probably for the same reason we have PDPs (personal data processors), people back then were frightened to call them computers.
Do you have any proof that there is (or was - it's unclear when you are talking about, as you say both "we have" and "back then") something called a "personal data processor", so named because people were frightened to call it a computer?
Or have you just made the whole thing up?
Or have you just made the whole thing up?
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http://www.hampage.hu/pdp-11/main.html
Maybe the word frightened was a bit ott but they wanted to get away from idea of a big computer costing $1m+, so they called it pdp instead.
Maybe the word frightened was a bit ott but they wanted to get away from idea of a big computer costing $1m+, so they called it pdp instead.
Indeed, but in Digital's case it stood for "Programmed Data Processor" rather than "Personal...". Brings back memories - I spent 20 years working with PDP-11s of various types, then MicroVAXs and then huge VAXClusters. 11yrs of them working DEC. Good times.
The original DLR trains used PDP11/23 single board computers to control them, and larger PDP-11s in the control systems. I expect they've been superseded by now.
I thought you might be referring to the DEC PDP range.
1) PDP did not stand for Personal Data Processor.
2) That was just a product name, like System/360, AS400, Nova, Macintosh, 1900, TaihuLight etc etc.
3) A contemporary Digital Equipment Corporation publication re the PDP-1:
4) A contemporary review:
So yes - it was freely called a computer by the makers and others. It just didn't have the word 'computer' in it's product name.
1) PDP did not stand for Personal Data Processor.
2) That was just a product name, like System/360, AS400, Nova, Macintosh, 1900, TaihuLight etc etc.
3) A contemporary Digital Equipment Corporation publication re the PDP-1:
4) A contemporary review:
So yes - it was freely called a computer by the makers and others. It just didn't have the word 'computer' in it's product name.
You are correct in PDP stands for programmed data processor, not personal data processor.
As the article I linked above says: In those days the word "computer" referred to a big, power-demanding electrical thing which was way too expensive (more than a million dollars), so DEC decided to name their product "Programmed Data Processor".
So in essence they wanted to disassociate it with the big, expensive power hungry devices, which is why I suspect we don't call PLCs computers either.
As the article I linked above says: In those days the word "computer" referred to a big, power-demanding electrical thing which was way too expensive (more than a million dollars), so DEC decided to name their product "Programmed Data Processor".
So in essence they wanted to disassociate it with the big, expensive power hungry devices, which is why I suspect we don't call PLCs computers either.
I don't think DEC exist anymore, I believe they were bought out by Hewlett Packard who later merged with Compaq.
That's correct - I left DEC and went to Reuters about 6 months before the HP buyout. HP kept some of the product line, notably the VAXes, going for a while, alongside the newer Alpha systems.
They should have dumped PA-RISC and carried on with Alpha.
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