Re: HP 9821 - display and tape transport issues #VintageHPComputers

Dave McGuire

Every company has fanboys, even evil ones.


On February 3, 2020 3:19:08 PM "Steve Leibson" <steven.leibson@...> wrote:
Hard to square your views of National Instruments with the 4000 to 5000 screaming fans I saw annually at NI Week in Austin. I'm sorry you seem to have gotten bad treatment from them, but my mileage definitely varied over the span of 35 years.

On Monday, February 3, 2020, 12:07:20 PM PST, <mariuszmleczko@...> wrote:

RIK: "A lot of transport problems are caused by a bad working EOT sensor, the LDR’s used in the system to detect the end of tape deteriorate and the resistance changes permanent to a low value."

I did a quick and very simple test. It is possible to run LDF, MRK, REW commands etc. with the opened cassete deck (without tape)....if at the same time top-right "cassette presence sensor" is pressed.
So I started it this way, trying to blink into a sensor by a pretty strong phone LED lighter, reaction.

Of corse I'm going disassemble and measure EOT resistance anyway, but think also - if it was OK (and it's logic), then should be some reaction on my simple test.

Dave McGuire, AK4HZ
New Kensington, PA

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