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Comment: Re:Half a century (Score 1) 113

by Jecel Assumpcao Jr (#47266227) Attached to: Unisys Phasing Out Decades-Old Mainframe Processor For x86

I used a B5500, at UC Santa Cruz, in a summer course on computer architecture in 1975, taught by one of its designers. Burroughs donated the obsolete machine, and we stepped it through instructions from its maintenance panel, watching the stack hardware work. We were also taken up to Xerox PARC to meet Alan Kay and see the original prototype Alto machines, years before Steve Jobs did. (They were really Data General Nova machines inside, with different microcode.)

The Altos were not too Nova-like, but the built-in part of their microcode did implement the Nova instruction set (except that the I/O instructions were used for other stuff). Alan had been previously using Novas in his projects (Smalltalk-72 was first implemented in Nova BASIC and then assembly, for example) and this allowed him to quickly port to the Alto.

Comment: forgot rule 12 of evil overlords (Score 4, Funny) 196

by Jecel Assumpcao Jr (#46664365) Attached to: Five-Year-Old Uncovers Xbox One Login Flaw

I guess their team of advisors is incomplete:

"12. One of my advisors will be an average five-year-old child. Any flaws in my plan that he is able to spot will be corrected before implementation."


"60. My five-year-old child advisor will also be asked to decipher any code I am thinking of using. If he breaks the code in under 30 seconds, it will not be used. Note: this also applies to passwords."

Perhaps Microsoft doesn't consider itself evil? Lots of people no longer do. At least they followed rule 32 in this case.

Comment: Re:Jetpacks, flying cars - same problme (Score 1) 127

by Jecel Assumpcao Jr (#46391771) Attached to: The Ephemerality and Reality of the Jetpack

Fluids "love" to twist, so laminar flows (such as the curtain of air along the inner surface of air amplifiers) don't always get the best results. The laminar flows seem so quiet and smooth so it is hard for our intuition not to consider them to be the way to move mass with the least energy.

Vortices can scale very well. I always point to the Red Spot on Jupiter as an example. Can one be generated on a scale that could keep a car or a person suspended in mid air while using less fuel than a helicopter? I think it is possible, but haven't proved it yet.

Comment: Re:Jetpacks, flying cars - same problme (Score 1) 127

by Jecel Assumpcao Jr (#46389851) Attached to: The Ephemerality and Reality of the Jetpack

Stubby lifting bodies can be practical at interesting cruise speeds, but you wouldn't want to take off or land at such speeds. Adding VTOL capability would solve that problem, but then we are back to the big and slow propellers issue you explained so well. I believe it is possible to convert a small, low thrust, high speed jet to a high thrust, low speed one with no moving parts. Air amplifiers actually increase thrust below 5cm in diameter but reduce it for larger sizes, so you have to figure out why it doesn't scale and fix that. The Dyson fan (, for example, is a terrible jet engine.

Comment: failed to learn from history (Score 1) 285

by Jecel Assumpcao Jr (#44890041) Attached to: Brazil Announces Plans To Move Away From US-Centric Internet

One of the issues that led to Brazil's "reserved market" policy (1977 to 1992: no foreign companies could make mini and microcomputers and there were no imports) was that in 1974 the government got so tired of US spying (including on companies such as Petrobras) that they set up a task force to create a cryptographic system for Telex machines (to be expanded to voice later).

Comment: Re:It was all about cost (Score 1) 99

by Jecel Assumpcao Jr (#38472742) Attached to: Reinventing Xerox PARC As a Money Maker

Some small corrections:

Data General Nova machines were popular at Xerox PARC before the Alto was developed, so one of the various instruction sets that the Alto supported was that of the Nova allowing old software to be easily ported to the new machine. Other than that, there was no relation between Xerox and Data General.

While the Alto and its successors (including the Star and specially the Dorado) were very expensive, there was the Notetaker project that would have had a huge impact if it had been released. Imagine a $3000 machine in 1979 like the future Compaq portable but with a mouse and GUI. Don't pay attention to what the Wikipedia or the Computer History Museum say about the machine, by the way, but look at the original documents instead:

The original plan was to create a Xerox microprocessor compatible with the Alto and use two 8086 for I/O. Imagine how cool that would have been! But the group was forbidden to do their own chips, though there was a division of PARC for doing just that. So the design was changed to three 8086s instead. And as neat as this was, there were plans for a cost reduced Notetaker 2. An executive flew from the east coast specially to kill the project and make sure it really died because the board had decided to keep Xerox outside of the silly microcomputer business. They changed their minds a little later and gave us a Z80 CP/M machine after IBM came out with their PC.

The only good thing about this was that the Notetaker's designer, Douglas Fairbairn, was so upset over the cancellation that he left PARC and founded VLSI Technology Inc. (VTI) which made possible for small companies to design their own chips. Like Acorn and their ARM.

Comment: banned for life for using real name (Score 1) 533

by Jecel Assumpcao Jr (#37000632) Attached to: Wikipedia Losing Contributors, Says Wales

I find it ironic that several people are proposing that demanding real names would solve some of Wikipedia's problems because I was banned for life for using a "spam user name", which happens to be my real first name (I have never used a nickname since I got online in 1986, except in systems that use numbers as user IDs). Now I know that is not the real reason, but it is the official reason and the only option they offer for getting my account unbanned is to post a special message selecting a different user ID, which then wouldn't be my real name.

My guess is that the real reason I was banned was because my home page (which was deleted) only had a short phrase about me and a link to my home page, which is a company page. When I created my account (a few years before the guy who banned me), I took a quick look at a few other user pages and most were like this so I just copied their style. If this is not acceptable, then just delete the page. I don't care: I was asked to create a page when I created the account though I didn't really want to. But banning for life seems a bit harsh.

Comment: Re:DEC scared IBM in the 80's (Score 1) 172

by Jecel Assumpcao Jr (#35138828) Attached to: Computer Industry Mourns DEC Founder Ken Olsen

For DEC they could have gone downscale to PCs, but the profit margins are too low: it's a commodity item. IBM doesn't build PCs anymore; they sold their PC business to Lenovo.

People, including Gordon Bell, like to mention Ken's "Nobody needs a computer in their home" quote to say he lacked the vision to get into the PC market. I don't agree - as much as it saddens me, the home computer was a fad that had died out by the 1990s. People have PCs, which is a business machine, in their home offices.

While DEC's PC efforts failed, this 1982 movie shows that they did try:

This approach, trying to leverage their PDP-11 and PDP-8 technologies, had a better chance of working than their later industry standard stuff, like the Rainbow. But I think they were about three years too late.

Comment: Re:first computer with stored programs? (Score 4, Informative) 97

by Jecel Assumpcao Jr (#34876264) Attached to: EDSAC Computer To Be Rebuilt

None of the early Zuse machines were stored program computers - they had a relay memory for data and got their instructions from punched tape. The table in the Wikipedia page about the Z3 seems about right:

The Manchester Baby was the first stored program machine, quickly followed by the modified ENIAC (the original used patch panels and cables) and then the EDSAC. Since the Baby was created to explore ideas for the EDSAC rather than as a usable machine on its own, I guess if you squint enough the article is right in an Obi-wan kind of way :-)

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