The untold story behind Apple's $13,000 operating system | Hacker News Reader

The untold story behind Apple's $13,000 operating system

cnet.com

40 pointsstmw20 comments

I keep hearing about Woz's masterwork disk controller. Any recommendations on where to read more about how he made one with so few parts?

He basically did super careful timing of the software to allow the main CPU to do the controlling. Because timing needs to be precise the software had to be perfectly timed down to the cycle. Woz's designs were very tightly integrated with both software and the electronics, and he would use every part of an IC to keep the count down.

The Wikipedia page on the Integrated WOZ Machine (https://en.wikipedia.org/wiki/Integrated_Woz_Machine) has some useful links:

- specification of the integrated circuit version: http://www.brutaldeluxe.fr/documentation/iwm/apple2_IWM_Spec...

- interview with Woz on the design: https://web.archive.org/web/20120212185115/http://apple2hist... (worth reading for the quote “We worked all night the day before we had to show it [the disk drive] at CES. At about six in the morning it was ready to demonstrate. Randy thought we ought to back it up” alone. Source control was quite different at the time)

I had the same fascination and tracked down the patents which explains it all clearly. It's took a bit of work but wasn't super hard: https://www.google.com/patents/US4210959 and https://www.google.com/patents/US4742448

IMvhO, the genius wasn't so much the implementation (which in hindsight follows the essence of the function), but the boldness that enabled him to even look for such a simple implementation. However from what little I've read about him in those days, that was the way I thought. Maybe it's a odd distinction.

EDIT: I do have to wonder about the survivor bias in the CNET story. If Apple had crashed and died like it almost did, we would never have see stories like this.

Yeah. I've read all of folklore.org and I bet there's an equal set of fascinating stories that were never written by all the companies that failed to do what Apple did. It's a shame.

Right, reading about the Alto is one example - or even Atari lore - at least those are still out there..

You may also be interested in http://www.computerhistory.org/atchm/apple-ii-dos-source-cod..., which, among others, points to https://s3.amazonaws.com/s3data.computerhistory.org/atchm/do.... I think that PDF has the design on page 4.

I think he used some software routines on the 6502 CPU to do the work of sending data to the drive. This was very timing sensitive so be partitioned out some of the low level sequencing to the controller hardware while the rest was done by the very timing sensitive software routines. This technique is called bit-banging in general.

There is a BYTE magazine interview where he talks about it:

https://apple2history.org/museum/articles/byte8501/#diskdriv...

For some reason, the article reads like a high school writing assignment that required a minimum number of words. It reads like a puff piece. I can't figure out why.

Before anyone replies that I didn't understand the article, I programmed on the Apple //e back in mid 80s in 65C02 assembly.

35 days = 5 weeks = 25 work days = 1000 working hours (assuming a 40 hour workweek). that works out to $13/hour for a programming contract. even with inflation accounted for ($49 in today's dollars), that's low. am i missing something? maybe they only worked half the time (which brings the effective rate to $98)?

Was computer programming back then as lucrative as it is now?

Couldn't find much on salaries for 1970s, but here's a resolution to hire a junior programmer for ~$10.6k/year in 1979. Seems like the $13k referenced was not a huge amount, but about an annual salary for a single dev.

http://www.co.walworth.wi.us/Committees/CBoS/pdfs/2015-2016/...

Here's another reference to programming costs:

"Computerprogramming and operational costs for 1978 wil be $12 300." Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1819069/pdf/can...

They do mention $35K/year salary at some point in the article.

25 * 8 = 200, where does the 1000 come from?

you're right, had a brainfart there. in that case it's much more reasonable at $65/hour.

I had an Apple II+ in 1979. I got it with the disk drive, but some of the software was still distributed on tape, because the drive was optional.

Funny because VisiCalc didn't even use DOS. They elwrote their own system on RWTS if I recall correctly.

Every company will have told and mostly untold stories in their success.

Very true, the success has told and untold stories.

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