S100 address buss troubleshooting
cctalk at randy482.com
Sun Jun 5 14:39:09 CDT 2005
From: "Richard A. Cini" <rcini at optonline.net>
Sent: Sunday, June 05, 2005 2:25 PM
> Interestingly, in this unit, the front panel power switch is not used.
> There is a jumper on the PC board which bridges the connector for the
> switch. A new power switch was inserted in the back panel and wired
> directly in the line.
> About the UL listing, I thought it interesting how exposed line voltage
> was. It's very easy to touch line voltage if you're not careful.
In the 70's it was assumed that you knew what you were doing today a device
that is designed to be user serviceable with open line voltages would never
Imsai built to a high standard but they assumed they customer had basic
understanding of electricity.
Recently there was a power blackout where I live. I started up my gas
generator (5500 watts) and used high quality extension cords to hook up the
TV, satellite reciever, and refidgerator, and some lights. My neighbor had
a tiny generator (800 watts) he knew nothing about. I helped him get his
going and told him to get a good extension cord, I plugged it in and handed
him the other end and told him to use that for power. He pointed out that
the cord had a female socket and asked how to plug it into the house wiring
to power the whole house :)
> -----Original Message-----
> From: cctalk-bounces at classiccmp.org
> [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Randy McLaughlin
> Sent: Sunday, June 05, 2005 1:07 PM
> To: General Discussion: On-Topic and Off-Topic Posts
> Subject: Re: S100 address buss troubleshooting
> From: <shoppa_classiccmp at trailing-edge.com>
> Sent: Sunday, June 05, 2005 11:49 AM
>>> Be careful after turning off the computer and don't pull the cards
>>> until you are sure the voltage levels have dropped
>> For that matter, if yours has a power switch on the front panel, be
>> careful what you touch in the vicinity of that switch, even after
>> you've turned it off!
>> The rightmost switch was truly a "user wires it how he wants" switch,
>> and when you bought an IMSAI it came with artwork to let you make a
>> transparency layer that matched the function you chose. (Which is why
>> I find these arguments about keeping original front panel
>> transparencies so amusing.)
> All of the S100 systems I've dealt with have had the line power exposed
> somewhere, none would ever pass UL testing.
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