[AT] OT Cooling Electronics was Statistics In Tractor Manufacturing

[deanvp at att.net]

Bob,

 

Yes, you were there during the same time I was. Imsai knew how to market and grow a company. Everything Mitts did not have.  I had a Mitts 8000 at one time but right now I don’t remember what I did with it. I do have an original Radio Shack TRS-80 and a North Star computer here someplace.  They are probably old enough to be worth something again. 

 

 

Dean VP

Snohomish, WA 98290

 

From: AT <at-bounces at lists.antique-tractor.com> On Behalf Of rbrooks at hvc.rr.com
Sent: Monday, September 23, 2019 3:07 AM
To: Antique Tractor Email Discussion Group <at at lists.antique-tractor.com>
Subject: Re: [AT] OT Cooling Electronics was Statistics In Tractor Manufacturing

 

Dean

 

One of my first tasks when I went to work for LeCroy Research in 1974 was to assemble two IMSAI 8080 kits. They were used as part of a system used to active trim thin film resistors with a zenon laser. When I left there in 1983 they were throwing the system out. I still have one of the IMSAI 8080’s

 

Bob

Sent from my iPhone


On Sep 22, 2019, at 9:40 PM, <deanvp at att.net <mailto:deanvp at att.net> > <deanvp at att.net <mailto:deanvp at att.net> > wrote:

I’ll mention a completely tangential electronics cooling issue that probably most of you never heard about.  I’m going to go back to when God was a kid and the Mitts “Altair” 8800 Computer was first coming out as full working computers or they were sold as a kit that a hobbyist could assemble.  I don’t remember the exact year right now but both Microsoft and Mitts were still in Albuquerque, NM. 1975 or so.  Later Pertec aquired Mitts and started selling business systems using the basic Mitts computer. All packaged up as a nice system for small business owners. Mitts didn’t know how to market or how to manage a fast growing business so they sold to Pertec who had no idea how to deal with a “micro-computer based business system. They were a disk drive manufacturer. Pertec started offering their systems and customers were having all kinds of weird results on their accounting software.  Turned out the cooling of the standalone computer case was adequate but when in a system enclosure the system occasionally was running too hot causing all kinds of weird results.  The real cause of the problem was how the ribbon cables were routed inside the computer case.  Properly routed everything work fine even in the system enclosure. The case by itself wasn’t that sensitive in an open standalone  environment.  How’s that for going back to when Microsoft only had 9 employees?  Does the name Imsai ring a bell?

 

Dean VP

Snohomish, WA 98290

 

From: AT <at-bounces at lists.antique-tractor.com <mailto:at-bounces at lists.antique-tractor.com> > On Behalf Of James Peck
Sent: Sunday, September 22, 2019 7:09 AM
To: Antique Tractor Email Discussion Group <at at lists.antique-tractor.com <mailto:at at lists.antique-tractor.com> >
Subject: Re: [AT] OT Cooling Electronics was Statistics In Tractor Manufacturing

 

They may have given up on trying to keep electrical cabinets cool by natural means. A couple of years ago  I encountered a US built mechanical servo press that had a chiller mounted up on a top platform and water/air heat exchangers inside the electrical enclosures. The temperature switches would shut the press down if the temperatures inside the electrical cabinets rose into the upper nineties. The fan motors on the heat exchangers would get some dirt from air in their bearings and bind up. The cabinet would overheat and the temperature switch would shut the press down with a fault.

 

[[Stephen Offiler] It's a reasonable default position to assume competence, but by no means am I trying to say there aren't many exceptions.  If you think about it, it's less reasonable to take the opposite position and default to the assumption of incompetence.  You'd have a hard time ever trusting anything.

 

[ Jack] Around 40 years ago I was involved with technical support of a product that used an early PLC mated to DC Drives in cut to length on the fly machinery. At room temperature of around 98 oF, it would start to miscount. In fact, you could put your finger on the chip where the calculations were being performed and burn it. A muffin fan blew air in the direction of the overheated chip but wires obstructed the flow.

 

I went to R&D and asked what the test results were that resulted in the 40 oC rating. They said that was a standard rating. After some more questioning by me, it was revealed that there had been no testing done. 

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