5 Sep
2010
5 Sep
'10
9:34 a.m.
It has multiple serial ports. A/D, D/A and other
general IO can be done
via
serial communications.
It's certainly possible, but it wasn't that common at the time. Did
DEC
make ADC and/or DAC modules with serial interfaces for it? Was there
software to talk to such devices (other than send/receive a string
to/from a seiral port)?
As to not common, here (usa) it was, of course it wasn't cheap.
I will admit the only ADC/DAC modules I've worked with (as opposed to
complete instruments that have computer interface ports) are the HP ones
which of course have HPIB/IEEE488 interfaces. Was there an an RS232
equivalent of, say, the HP59313 ADC?
How does it
jsutify its name?
Packaged software. At that time
HP were selling ADC, DAC, timing generator, relay, etc
modules with an IEEE-488 interface. The ADC I am refering to is not a
complete DVMor DMM unit, but a simple 11 bit ADC with much the same
capabilities as the one that goes into a MINC-11 Were other companies
selling similar units with RS232 interfaces?
Yes, National instruments, Keithly, Simpson, HP[with options],
Tektronix and a multitude of smaller companies. It was not uncommon to use a complete 3-5000(US$) instrument
just to test a specialized part because it was flexible or
offered a very high order of resolution and accuracy
(>5digits). Most ADC board were usually 10 to maybe
14 bits when the application needed 20 or more.
That depends -- a lot -- on the application. I've done things where I'm
glad of the (reliable) 5 digits from an HP DMM. I've done things where 6
bits wre enough/
You only have to remember that by time the PDT series hit
the 8080/8085/z80/8048/8051/6502/6800 cpus were well
entrenched in the instrumentation market and but needed
Personally I wouldn't consider (or have considered at that time) a
machine as an instrumetnion controller if there wasn't an IEEE-488 port
eiterh built-in or as an option.
a host with more power to do serious data reduction
and
HP9845? HP9000/200 machines were starting to appear around then too.
-tony