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Steve Wozniak's floating point routines for the 6502

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Re: Steve Wozniak's floating point routines for the 6502

#41
post #16
post #3

I don't think many people realize that Woz's dad was an electrical engineer at Lockheed who would bring home computer manuals that Woz would read as a kid. This seems to be a fairly effective way to create world-changing computer engineers.

If you gave computer manuals to kids today, they'd cry and beg for their phones back

Please don't take HN threads further into flamewar. Especially not generational flamewar, which is particularly contentless.

https://news.ycombinator.com/newsguidelines.html

Re: Steve Wozniak's floating point routines for the 6502

#43

Earlier quoted context omitted.

A 50-hour pilot in a Bonanza A36TC is insane, I had no idea Woz landed off-airport. I do checkouts in Bonanzas, and the more typical A36TC/TN pilot has 500 hours' experience or more. (Some of us still use small planes like ATVs -- but if the description of Woz' experience in the incident is accurate, this is like taking a Lamborghini out with a fresh driving permit) [1] https://www.cultofmac.com/465778/today-in-apple…

> With Woz, who had only flown for 50 hours at the time, at the controls, the plane climbed too abruptly. Then the aircraft stalled and careened through two fences into the car park of a skating rink. Woz later said he thought Candi might have accidentally leaned on the controls. How could leaning on the yoke (or any other control) cause a stall? She'd have to pull back on it to force a climb like that. I'm kind of a…

> I'm kind of amazed he was able to fly a plane like that at 50 hours. A turbo-charged engine requires an extra certification step right?

The wikipedia page for the Beechcraft Bonanza says: "The NTSB investigation revealed Wozniak did not have a "high performance" endorsement (making him legally unqualified to operate the airplane)" and links to https://web.archive.org/web/20121019022620/http://www.ntsb.g...

Re: Steve Wozniak's floating point routines for the 6502

#44

Woz was scary good at both hw and sw (author of Apple BASIC.) If you have time, go through his various Apple documents online. I believe he was never the same after his small plane crashed. (Back then, wealthy people used small planes like ATVs, and had about the same safety record.) I worked with another hw engineer of similar ability back in the 80s. Mind-blowing watching him just pick up a pen and draw out a compl…

I wonder why rich people have such a high urge to fly small airplanes. It seems to expose you to a lot of risk, which you could easily avoid (I’ve lived a considerable number of years without facing a single situation where I was likely to fly an airplane).

If you have a free afternoon I would recommend booking a "discovery flight" at a flight school. You go up, with a certified instructor, and learn the fundamental controls in a relatively safe environment.

It can be an interesting experience, even if you have no desire to become a licensed pilot.

Re: Steve Wozniak's floating point routines for the 6502

#45
Steve Wozniak is one of the few people of note in the tech industry who, the more I learn about them, seems more and more worthy of my respect. When I hear others speak of their sense of humour, how they stuck by their friends even when those friends clearly took advantage of them, the work and exemplary engineering skill they so clearly poured into their projects, their financial success and, then after having enjoyed that success, their leaving that successful business behind to engage in improving things for the future - to invest in educating children - I feel a sense of loss. Steve Wozniak just seems like the kind of person one would be lucky to have the opportunity to have as a friend one could learn so much from. It's rare to feel that way about people one doesn't know first hand and, while it does feel like missing out, it's nice to have a prominent example of such a person, a financially successful person, within the tech industry - often a dark place indeed. A reminder that one doesn't have to be soulless in order to succeed in the valley - just skilled and, hopefully, lucky. "So shines a good deed in a weary world."

Re: Steve Wozniak's floating point routines for the 6502

#47
post #37

Earlier quoted context omitted.

> With Woz, who had only flown for 50 hours at the time, at the controls, the plane climbed too abruptly. Then the aircraft stalled and careened through two fences into the car park of a skating rink. Woz later said he thought Candi might have accidentally leaned on the controls. How could leaning on the yoke (or any other control) cause a stall? She'd have to pull back on it to force a climb like that. I'm kind of a…

I read a description why aircraft like the Bonanza A36TC are more unforgiving. I think he said because because of higher power, higher speeds, and airfoils to match these aircraft can rapidly leave the stable flight envelop. It takes fast reflexes and knowing what you are doing to get them back. And because they are fast they'll fall out of the sky very quickly in a stall. Fast reflexes comes from being young or bein…

> It takes fast reflexes ...

No, most Bonanza owners are mid-career doctors, dentists and lawyers. Never seen a teen fly one.

Also, you generally have a second or two at least to deal with issues. Hence the old saw about "winding your watch before reacting to an airliner emergency."

> There is a reason the air force trains 20 year old's to fly jet fighters.

I talked to an ex-Air Force, now civilian flight school owner about that.

He said the problem with 30 year-old military aviation students is that they talk back when fed b.s., unlike kids. So it's a general discipline issue, not an age one.

Re: Steve Wozniak's floating point routines for the 6502

#48
post #30

Woz was scary good at both hw and sw (author of Apple BASIC.) If you have time, go through his various Apple documents online. I believe he was never the same after his small plane crashed. (Back then, wealthy people used small planes like ATVs, and had about the same safety record.) I worked with another hw engineer of similar ability back in the 80s. Mind-blowing watching him just pick up a pen and draw out a compl…

> Woz was scary good at both hw and sw You damn-near gave me a heart attack then! :D I thought he had died for a moment, Phew!

He had a head injury as mentioned above. Hence the past tense regarding his exceptional engineering ability.

Re: Steve Wozniak's floating point routines for the 6502

#49

Having written a lot of 8 bit assembler for the 6800 microprocessor for 2K eproms, I can attest it is a very different skill from writing modern software.

Would love to hear more about this - have you written on your experiences?

No, and sadly I've lost the code I wrote, I don't know what happened to it.

Anyhow, programming an 8 bit 6800 for an embedded controller means keeping track of 6 or more things going on at the same time, while modern software focuses on one thing at a time and isolating it from everything else.

Those things include the contents of each register, the stack level, the size of the code, interrupts going off, polling that has to be done, counting cycles, etc. Organizing code into functions is a luxury not usually affordable.

It sounds tedious, but it was fun. I attached my own hard disk drive to my LSI-11, meaning I had to build an interface board and write a device driver. To figure out how to write the device driver, I dumped the floppy driver code. It was a marvel of tight engineering. The bootstrap loader was executing code only an instruction or two behind it getting loaded. I was just in awe.

Re: Steve Wozniak's floating point routines for the 6502

#50

Woz was scary good at both hw and sw (author of Apple BASIC.) If you have time, go through his various Apple documents online. I believe he was never the same after his small plane crashed. (Back then, wealthy people used small planes like ATVs, and had about the same safety record.) I worked with another hw engineer of similar ability back in the 80s. Mind-blowing watching him just pick up a pen and draw out a compl…

Lots of people were scary good at these things early on. Not everyone was as good as Woz, of course.

When you can fit the entire architecture into your head, all the way down to the chips and board layout, you'll find that you're capable of quite a lot on that platform.

A human with a skillet that has scaled up as much as computing hardware has scaled up is going to be virtually impossible to find, if not actually impossible.

Systems today are just too complex for one person to understand at the breadth and depth that Woz understood the earliest Apple hardware.

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