Comments for page: Building SBC6120

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Posted by Garrett Nievin February 02, 2014 - 07:31 pm
Is it possible that you swapped R6 and R8 on the SBC?

Posted by Steve L. August 30, 2013 - 09:14 pm
Hi Don, Yes, I tested the chip and it works fine, booting OS/8 and running Focal programs. This Hong Kong eBay vendor, SunElectronic has over 5000 transactions, with a 99.4% satisfaction rating, so I had little doubt. As much as folks love to hate eBay, gotta love the vendor ratings and customer protection system.

By the way, regarding fakes, all of the HD1-6120 chips I have seen have been in ceramic packages which look like a sandwich and are distinctively different from their plastic brethren. With its prominent Military business, Harris seemed to have quite a preference for ceramic packages. They have the advantage of being hermetic and are thus more reliable. When I worked there, it was said that there was little difference in the cost of plastic and ceramic packages (excluding "jelly bean" devices) and that other chip vendors were simply using them as a way to divide their hi-rel and commercial markets.

Posted by Don N August 30, 2013 - 07:24 pm
Have you tested and validated that your Chinese HD1-6120 is a functional, real chip? There are some unscrupulous vendors that take old random chips, or just plain mechanical fakes, and remark them as something that sells for $$$.

Posted by Steve L. August 30, 2013 - 10:54 am
Thanks for the followup, Kevin. I see how you might think that, given the comment. It's fortunate that the Chinese seem to have a significant number of HD1-6120 chips squirreled away. I just bought a backup chip on eBay at a reasonable price, from a Hong Kong vendor and there were plenty more. It arrived a week later. My experience in the vintage audio arena has been that vintage semiconductors are generally available at fair prices, at least in the modest quantities that SBC runs have been. So it's really just a question of whether and when Bob feels up to mounting another offering, making boards or making Gerber files available. I'm optimistic that we may yet see more runs of this platform made.

Posted by Kevin M August 30, 2013 - 10:30 am
OK, thanks Steve. I think the source of my information was the paragraph on Kickstarter stating: ďI have enough CPU chips to build 30 units. Thatís it, and there is no ready source for more. Youíll notice that the reward quantity is limited to 30, and thatís why. When those are all spoken for, there will be no more!Ē

Posted by Steve L. August 29, 2013 - 04:50 pm
Hi Kevin, Not necessarily. A comment on the Spare Time Gizmos Yahoo forum about the Feb 2013 run being the last, was based on a comment on Steve Gibson's site. The trouble with that was was that he was referring to the 2010 run! So I do not know of a credible statement that we have definitely seen the last. Any further information you might have would be appreciated. In any case, even if Bob were to decide against running any more, the board designs might well be made available for group buys to run, at some point in the future. I have already determined that significant quantities of the HD1-6120 are available from China.

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