28 Oct
2013
28 Oct
'13
12:27 p.m.
On 10/27/2013 12:20 PM, Tony Duell wrote:
The 5160 and 5170 cases have that little blanking plate over the keyboard
connector. Perhaps that was a convenient hole to put the lightpen cable
through.
I do wonder why IBM didn't put the lightpen signals on a convenient
connector on the back fo the card, though. Jut abotu any use fo them
requires them to be connected to an external device.
Howere were you supposed to route the light pen
cable out of the system
unit case? There is no obvious hole for it.
In the 5150, there's a nice hole that has a filler plug in it right
above the keyboard/cassette DIN connectors. AFAIK, no specific use was
ever singled out for it.
I always wondered why RCA called the single-phosphor kinescopes
"monochorme", but didn't call the three-phosphor ones
"polychrome" or
"trichrome".
Given that 'chrome' == 'colour', I guess it's becuase a
single-phosphoe
CRT can only display one colour, albeit at various intensities. But due
to the chracteristics of the human eye, the 3-phosphor CRTs can display
just about any colour that you can see. So 'trichrome' would not really
be appropriate. 'Polychrome' would be OK, I guess.
-tony