Blinking lights hidden

From: R. D. Davis <>
Date: Tue Jun 20 23:23:01 2000

On Tue, 20 Jun 2000 wrote:
> Well, I know the only time I need to see the LED's on my /44 or /73 is when
> I'm working the hardware, at which point I've got the card cages opened up.
> It would have taken serious work, to get those LED's to show up somewhere
> other than on the card itself, and doing that work would place restrictions
> on the chassis.

Not necessarily... the boards could have been mounted horizontally
with the LEDs at the edge of the boards facing a plexiglas panel, or,
the front panel designed with punch-out areas where LEDs attached to
inexpenive ribbon cables could have been connected.

> Besides who is to say I want controller 'X' with it's
> particular LED scheme? Maybe I want controller 'Y' which has a totally
> different set of LED's, or maybe none at all.

See above. A front panel with punch-out areas (recloseable if board
for LEDs is removed), where the LED displays for various boards could
be installed.

> A better question might be, why not. It makes sense from both a design
> standpoint, and a cost standpoint.

I can see a cost standpoint, but I suspect the design standpoint was
influenced by marketing wanting to hide the intricacies of the machine
from the users.

> Note: All these comments are relative to PDP-11's and VAXen, I'm not
> familiar with SMD drives or NCR applications processors.

It just seems reasonable that a drive's display, which lets one know
certain things about what the drive is doing, as well as diagnostic
info., is more useful on the front panel, rather than hidden behind
something that needs to be opened up or removed in order to see it.

R. D. Davis             
Received on Tue Jun 20 2000 - 23:23:01 BST

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