"Floppies: The Disks That Changed the World"

One of a series of podcasts - and with transcripts too. (Previously: Minis, Mainframes, Personal Computers, and 3 previous series too.)

The floppy disk was one of the greatest breakthroughs in computing. It helped spin up the software industry with a format that endured for decades. And in some cases, it’s conserved treasures once thought to be lost forever.

Before floppy disks came along, computing was weighed down by punch cards and magnetic tapes. Steven Vaughan-Nichols describes the magnitude of the changes brought by the floppy disk. Dave Bennet explains how the need for permanent storage, which was also easily mailable, led to the first 8-inch drives. George Sollman recalls how he was tasked with creating a smaller floppy, and what unexpected sources inspired the next design. And when Sollman showed it to the HomeBrew Computer Club, a couple of this season’s usual suspects asked him to see more. And the rest is history.

via heurekus on mastodon

Really, you can give Steve Jobs the credit for being the person to introduce the floppy drive to the PC world. People are running this operating system called CPM 80 and there are literally dozens of small manufacturers and some big ones like DEC making CPM 80 computers and all of these computers use the 5.25-inch floppy drive.


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Jobs has legitimate place in the history of home computing but… to credit him with introing floppies?
wot? More ‘jobs our lord and savior saint of computing doer of no wrong’ propaganda and whitewashing…waves cane, grumble.

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I think we shouldn’t be surprised to see some claims we can’t quite agree with. But isn’t it the case, that by having Woz able to build a super-cheap disk controller and being able to buy naked drives cheap, Apple succeeded in bringing the price of floppies down a lot, and so promoted their adoption?

Reading the relevant part of the transcript, the narrative seems to be that Shugart wanted to make something and Wang wanted to buy something - for his large machines. It was Apple that pioneered floppies in small machines (this being implied by the text, not something I’m claiming) and then CP/M made floppies normal, at which point the IBM PC could choose to have floppies as a normal thing to do.

I could buy Woz being the genius engineer to get the smaller floppies able to work at a consumer level but (citation needed.)

that said, everything I have ever read about the apple II development? Woz worked black magic. I have no other explanation.

The problem with the Mini-floppy it (85K 35 track SSD) was too small for anything other than BASIC or game files at that time. After a few years it was time to upgrade the system with new hardware.:frowning:

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I’m not sure of the timeline of disk drives for CP/M systems. In the UK, disk drives were rather rare and expensive, I think (but I was only a schoolboy in the 70s) and the Apple II was the one case where I saw floppy drives.

My understanding of the history is that it was VisiCalc which caused the major takeup of the Apple II, and was a big boost to the idea of selling software as a business.

By the time I got disk drives, they had more than 100k capacity. But even that is enough to run a small business, I’m sure, and enormously better than tapes.

If the story I heard is true, then credit for the Apple II floppy disk should go to Mike Scott. He looked at one of the Apple ads which claimed that it could be used for balancing your check account. So he tried doing that and found two problems: it was not practical to load and save your data with cassette tapes and Apple Basic was integer only so couldn’t handle cents.

He wanted Woz to fix this so they wouldn’t be liars, but Woz said he could only deal with one of the problems at a time. So Scott decided that Woz should focus on adding floppies while he would buy a floating point Basic from Microsoft.

The only Jobs floppy story I am familiar with is how the Mac team had to trick him into switching to the Sony 3.5".


That is, as far as I know, correct. However, as far as I can see, the only real contribution there is helping a bit to more quickly reduce the cost of diskette drive systems. Consider:

  • 8" drives were widely used on microcomputer systems before the Disk II (not a lot of people were running CP/M with only tape :-P).
  • Radio Shack introduced their disk system for the TRS-80 Model I only a month after Apple released the Disk II. I can’t find 1978 pricing, but their 1979 pricing was $500 for the drive, which was about the same as Apple. (You did need to have the $300 expansion unit, which contained the disk controller, but the base Model I was cheaper than an Apple II, so it more or less evened out.)
  • Commodore didn’t introduce their drive unit until a year later, but you could plug multiple computers into a single drive unit, greatly reducing the cost for computer labs in schools and the like.

By 1980 there were a lot of computers with diskette drives available; I very much doubt that would have been significantly different had the Disk II never existed.

Yeah, there seems to have been something weird going on there with the U.K. and perhaps even all of Europe: disk drive take-up was much slower than in North America, and cassettes remained popular for much longer. I’m not sure why that was.

That’s a great story. And it’s rather ironic, too. Consider:

Instead, the Lisa hardware designers (Paul Baker, Bob Paratore and others) solved the problem by including a little Apple II, with its own memory and microprocessor (but clocked twice as fast), inside the Lisa to control the Twiggy drives.

That’s pretty much exactly the opposite of Woz’s approach to drives on the Apple II, which was to minimize the amount of logic by removing custom controller circuitry and having the main CPU do the work instead. (The drives Woz originally got from Shugart were SA-400s that had failed QC and had had their controller boards removed. When Apple went into production, the SA-400s without the controller circuitry that they ordered were designated SA-390s. Somewhere that whole story is documented, and a link to that would be a vauable addition to this thread, correcting or at least clarifying that podcast.)

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The magic of floppies is that you can swap them.

While more rare on the personal machines, 2 drives were pretty ubiquitous on CP/M machines. Swap out the program diskette for the data diskette(s), and you have 160-200K of storage. That’s actually quite a bit for a small business. Several hundred addresses for a mailing list. 1000 parts. 200-500 invoices. Having a “monthly floppy” was not unheard of. Two floppies and “mail merge”, and you have a 1000 letters printed out.

Could it be a pain to consolidate? Sure, swapping floppies was a drag (ask anyone with a 128K single drive Mac). But worth it given the other value the system offered.

The TRS-80 machines could go up to four floppies. Others, I’m sure, could too. But Radio Shack used to have pictures of such systems.

One of the issues with CP/M is the lack of directories. It has User spaces, which can be abused as such in a pinch, but it was a pretty simple file system.

But since the original target was floppy based systems, you didn’t use directories – you used floppy disk labels and swapped stuff around. It’s an archaic concept today, but routine back in the day and we made do.

I wrote some programs that utilized cassette tapes for storage, but they pretty much had to read the entire thing in, let the use process it, and then save it all out. I actually tried to have several “files” per tape, but that didn’t work out well at all.

In college, they had some public Apple II machines with a single floppy that was sort of chained to the computer. It was probably measured in hours before someone hit them with a hole punch, flipped them over, and stuck Lode Runner on the back. The disks were single side, so it was common to punch a new notch with a hole punch and flip the disk to use the other side.

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[Edit by moderator: see new thread]

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Great story!

Indeed, the general progress of technology and the march of Moore’s law makes most developments seem inevitable. But someone has to be first, and someone might well be a major influence, and as it happens, that might well have been Apple. If not them, it would have been someone else.

I think two things might be true: that prices were about double here than in the US, for whatever reasons, and that earnings were somewhat less here than in the US. So a fully equipped Apple II was (let’s say) about 4 times as expensive in real terms.

The Wikipedia article has some good detail but not a lot of citations:

It does have a couple of links to interesting magazine articles:

Actually there’s more, much more about Apple, Jobs, Shugart and 5,25" floppy drives in CHM’s Oral History Panel on 5.25 and 3.5 inch Floppy Drives. :slight_smile:


I’ll put this more strongly: this would have happened in pretty much exactly the same way, with the same timeline, without Apple. Radio Shack had a similarly-priced drive available for the TRS-80 microcomputer within a month of Apple’s release, so that clearly wasn’t a reaction to Apple, and I am pretty sure that RS sold more computers and drives over the next few years than Apple did.

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Along with the timing, I’ve dug up some pricing and sales figures that leave me convinced it was Radio Shack, not Apple, that was mainly responsible for bringing floppy drives to personal computer users.

First, keep in mind that everybody shipping a 5.25" floppy drive in '78 and '79 was using the Shugart SA-400, becuase that was the only 5.25" drive that was available. [wptrsflop] (The Apple drive was an SA-390, which is an SA-400 without Shugart’s on-drive interface board; the Apple controller and software dealt with things like driving the individual phases of the stepper motor. This didn’t seem to result in any real cost savings to the consumer: the Apple and TRS-80 drives, without controllers, were exactly same price: $499. [bytead] [rsc79 p.12])

The Apple II was released in June 1977 [wpap] at $1698 for a 16K system [ars]. (A 4K system was only $1298, but did not have enough memory to run DOS.) By mid-1979 this had come down to $1045. [bytead] The Disk II was released in June 1978 at $599 for the controller and drive; that price stayed the same through 1979. [wpd2] [bytead] So total system cost by mid-'79 was around $1650.

The TRS-80 Model I was released in August 1977 [wptrs], two months after the Apple II, and the disk drive system in July 1978 [wptrsflop], one month after the Disk II. I can’t find 1978 pricing, but in the 1979 catalogue a 4K computer was $499, the expansion unit (containing the disk drive controller) with 16K RAM was $448, and the drive $499, for a system cost of about $1450. [rsc79 p.7] [rsc79 p.10] [rsc79 p.12]

The TRS-80 was “top-selling personal computer of the trinity [Apple, TRS-80 and Commodore PET 2001]” and the Apple II “a distant third compared to the other two machines,” according to Ars Technica. The figures bear this out: the Apple II sold 43,200 units through the end of 1979, whereas the Model 1 had sold over 100,000 units by October 1979. The differences in early sales figures are even more dramatic: Apple sold only 8,200 units in 1977 and 1978, whereas Radio Shack sold 55,000 units in 1977 alone. [ars] [wptrs]

Sadly, I don’t have figures for drive sales (as opposed to the sales of system units without drives), but we do know that “[d]emand for Model I drives greatly exceeded supply at first.” [wptrsflop] But I think we can safely assume that in the first couple of years Radio Shack ended up with far more floppy-based systems out in the field than Apple did.

So I’m going to say that the Steven Vaughan-Nichols, and by extension the Command Line Heros podcast, is simply wrong, and it was Radio Shack that gets “the credit for [introducing] the floppy drive to the PC world.” Even if you wanted to make the argument that Apple was more influential in some way, it’s simply negligent not to mention a competing system that came out at the same time, was cheaper, and had far higher sales.


Note that when business people write about history they only care about revenue and not about units shipped. Many people who opted for Apple bought higher end configurations since if they were looking for low cost they would have gone with the competition instead. That allowed Apple to make more money while selling half or even a third as many computers.

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That’s not actually correct for all, or even many, business analyses, for reasons I won’t get into here. But it would indeed be better to compare number of drives shipped rather than number of system units shipped, as I touched on in my post. (For that analysis revenue would be directly proportional to drives shipped for both, since the drives were the same price.)

Unfortunately, as I also said, I don’t have figures for the number of drives shipped, but given that demand for TRS-80 drives was clearly high, and the massive difference in unit sales between Apple II systems and TRS-80 systems (the TRS-80 had sold at least three times as many units at any point in time, and as much as twelve times as many depending on when you set the cutoff date for “influence”), I think it’s safe to assume that Radio Shack sold more drives, even if a significantly smaller proportion of their systems had drives.

But I’m always happy to see figures that clarify any of this!

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Thanks for the detailed post with lots of links, @cjs.

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I’ve just been reading through the oral history mentioned earlier, and it turns out to have some 5.25" drive shipment figures on page 19:

  • 1977: 44,000
  • 1978: 128,000
  • 1979: 497,000
  • 1980: 866,000
  • 1981: 2.2 million
  • 1982: 3.6 million
  • 1983: 10.5 million

These are clearly industry figures, since they rise dramatically even well after Shugart lost their market lead. (According to Wikipedia, even by 1978 there were ten different manufacturers producing 5.25" drives.) These also seem to be yearly figures, not cumulative, since it seems very unlikely that sales were flat from 1981 to 1982; Porter also mentions on page 37 that his 3.5" figures are not cumulative.

I’m inclined to trust these figures because they were given not by a panel participant but by Jim Porter, the moderator of the discussion, who presumably did some research before convening the panel if he was giving out such exact figures. (He had these written down, it’s mentioned on page 37.)

The most optimistic figure for Apple drive sales in 1978 is an attach rate of 2.0: two drives for every last one of the 8,200 Apple IIs manufactured to that point. Given the figures above, that would still be only about 12% of the market, leaving over 110,000 drives manufactured that year to be sold by other companies.

It’s hard to say how many Radio Shack might have sold. Subtracting a more reasonable (but still rather optimistic) share for Apple at a 0.9 attach rate, and assuming the 1977 sales to vendors other than Apple and Radio Shack doubled for 1978, that would still leave some 32,000 drives for Radio Shack, well under a 0.5 attach rate. (Remember, no other home computer manufacturers were selling drives in 1978.)

I wonder, after Apple and Radio Shack, where those other 50,000 to 100,000 (or maybe even more) 5.25" drives were going.

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TRS-80 users started buying third party floppy drives a lot earlier than Apple II users, so the official numbers from Tandy and Apple don’t show the whole picture.

While the CP/M business machine makers had much smaller numbers each, there were a lot of them so the total was significant. But I don’t know when the switch from 8" to 5.25" happened in this market.