It seems that every version of MS-DOS from v2.0 onward was actually developed by Compaq. I had no idea.
> That relationship had been established in late 1982. Back then, Gates had contacted Canion and asked, with some concern, if Compaq was trying to get into the operating system business. Surprised, Canion denied it. Gates told him that Microsoft was hearing worrying reports from the dealer network. People were buying copies of Compaq DOS, rather than Microsoft DOS, without buying a Compaq PC.
> Both men knew why: Microsoft DOS had never been a true copy of PC DOS, as Gates had admitted to Canion during the development of Compaq’s first machine. The differences had only increased over time, as Microsoft’s deal with IBM prohibited the same developers working on both versions. Compaq had made its own version of DOS since the beginning. With its singular focus on 100 percent compatibility, the result was a product that was more compatible with PC DOS than Microsoft’s own product.
> Word was spreading among computer buyers that Compaq DOS was better. Even people who owned other PC clones were choosing to buy that instead of Microsoft’s own public version. This could have created friction between Compaq and Microsoft. Instead, Canion did something extraordinary. Compaq withdrew Compaq DOS from sale unless it was specifically bundled with a Compaq computer. He then licensed Compaq DOS back to Microsoft.
> From Gates’s perspective, this was an incredible deal. He was able to halt all internal development on Microsoft DOS, saving time and money. From this point onward, every version of Microsoft DOS he sold was, in fact, Compaq DOS, with the digital equivalent of its serial numbers filed off. All Canion asked in return was that Microsoft never release the very latest version of DOS that Compaq provided it until after a few months’ delay. This was to make sure that Compaq always had a slight advantage in compatibility over its rivals.
> Canion even agreed to Gates’s request that they keep the entire arrangement secret, to avoid souring Microsoft’s relationships with the other clone companies. It would remain secret for almost 40 years.
I wonder if this is slightly mangled over the years?
MS-DOS wasn’t a specific IBM PC OS, it was designed to be generic 8086 OS. It was up to the OEM to adapt the machine specific code (mostly in IO.SYS / IBMBIO.COM) to their system. IBM owned IBMBIO.COM, and some of the utilities like MODE and FDISK, and early on Microsoft didn’t have its own implementations to offer for people building generic PC clones. You had to write your own, and hope they were compatible. Microsoft did eventually offer a generic MS DOS with an IBM PC type IO.SYS and reimplementation of the utilities, so perhaps those are descended from Compaq’s versions?
This is largely untrue. MS-DOS and PC DOS were both built out of the same codebase for most of the time MS-DOS was on the market. They didn't diverge until some point after DOS 5 (1991). If you look at the MS-DOS source code, you'll see an IBMVER define that controls whether to build IBM PC DOS or generic MS-DOS. The option was there in the first place because Microsoft initially sold MS-DOS to OEMs as a generic 8086 operating system. In the early 80s there were a bunch of computers that ran MS-DOS, but weren't PC compatible. These largely died out as time went on. DOS was barely an operating system, so there were a lot of programs that bypassed it and accessed the hardware directly. None of those programs worked on non-PC clone MS-DOS computers, so most consumers chose PC clones for the far greater software library. What is true is that unlike most early 80s OEMs, Compaq built their version of MS-DOS with IBMVER set, so Compaq DOS was closer to PC DOS than many other early DOSs.
As time went on and Microsoft started selling more and more copies of MS-DOS to manufacturers making PC clones, MS-DOS and PC DOS grew closer together, not further apart. MS-DOS 3.2 (1986) was the first version that Microsoft made available in a packaged form to OEMs that were shipping PC clones (it was still available as source code to OEMs who wanted more customization). For previous versions, OEMs were required to write their own versions of several hardware specific utilities (such as FDISK.COM and MODE.COM) that were originally written by IBM. MS-DOS 3.2 contained Microsoft-written clones of these utilities. MS-DOS 3.3 (1987) was written entirely by IBM (not Compaq!), as most of the key members of the MS-DOS team were busy working on OS/2. Because it came out after the Microsoft-IBM joint development agreement, Microsoft gained the rights to the IBM-written utilities and the packaged versions of MS-DOS 3.3 and all later versions shipped with the same utilities as their PC DOS counterparts.
The closest thing to the claims this article makes is that Compaq did in fact maintain their source code license to MS-DOS and made enhancements to their version. The most notable example of this is that Compaq DOS 3.31 introduced a modified version of FAT16 that supported partitions larger than 32MB. I assume Compaq licensed this functionality back to Microsoft, as there's versions of DOS 3.31 branded for other OEMs, and support for Compaq's modified FAT16 (known as FAT16B) was included in MS-DOS 4.0.
I remember reading the quotes asking one of the founders why they left Texas Instruments and his reply was "the prospect of vast personal wealth".
My understanding is that they had pitched the IBM PC compatible machine to TI and had been rebuffed - TI had its own mostly compatible PC offering and the no one in charge was willing to admit it was a mistake.
I only ever had a laptop from Compaq, and it was the most robust and minimalist thing, like a solemn thinkpad, which is as impossible a statement as sincere. Then they got bought and I got one from their HP days that I returned straight away.
Very interesting. I'm curious what the os2museum.com can say -- if anything -- on this. A deeply technical perspective, as in knowing the actual bit-by-bit internals, can shed much more light.
os2museum.com was just recently able to trace how one particular DOS bug (more than two BIOS harddisk drives would make earlier DOS-versions hang at boot) was handled across different companies, and how and when exactly a fix made it into actual MS-DOS.
The context there was Compaq sold some of the highest-end PC systems, they were into 386/486, servers, UNIX, SMP, rackmount, RAID, etc, "IBM wouldn't sell you this stuff". So, reading between the lines there, Compaq ran into this problem first and 'fixed-it' in a backwards compatible way.
(Compaq had a fantastic reputation which they tarred with shitty consumer PCs. HPE still sells Proliants, and I'd guess they still use 'compaq screws'.)
I remember going to the huge Compaq Singapore factory in Yishun in 1992, which had around 1600 employees, to assess if we can take over the support of their Banyan Vines system, as a junior engineer. 7 years later, in 1999, they laid off everyone and closed the factory, which supplied 90% of Compaq's PC boards worldwide.
Compaq's CEO at the time of the Compaq downsizing and eventual acquisition, Michael Capellas, is now the advisor to the company I work for. And the man who sold the Banyan Vines solution to Compaq in the 90's is now my boss.
> By March 1989, however, Hugh Barnes—now Compaq’s vice president of engineering—started to notice that Intel’s best chip people were being reassigned to other teams. Some quiet investigation revealed the cause. Sun Microsystems, one of Intel’s rivals, had announced chips based on a new design approach called reduced-instruction-set computing (RISC). For Intel, this presented a threat to its higher-end, large computer and mainframe markets. It was now shifting to focus on that threat instead.
> At a hotel room in Silicon Valley, in April 1989, Canion and Gates met with Andy Grove and Intel chair Gordon Moore to try to persuade them to stick with 486 development. After considerable back and forth, Intel reversed course. The new chip launched in late 1989.
Could this be the moment that forever saddled us (and Intel) with the cumbersome legacy of x86? It seems like a great cultural win for PCs in the moment, but in hindsight this decision almost feels backwards somehow.
IBM might have lost, yet thanks to the way computing has evolved, vertical integration has won in the end.
Going to a computer shop on a random shopping mall, usually only a few gamer PCs are available as composable desktops, 90% of computers on display are laptops.
Servers are mostly designed for companies with racks or hyperscalers.
Most non technical people nowadays only have a smartphone and a tablet as computers, with the integration of all 8 and 16 bit home computers PC compatible were fighting against.
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[ 2.7 ms ] story [ 37.0 ms ] thread> That relationship had been established in late 1982. Back then, Gates had contacted Canion and asked, with some concern, if Compaq was trying to get into the operating system business. Surprised, Canion denied it. Gates told him that Microsoft was hearing worrying reports from the dealer network. People were buying copies of Compaq DOS, rather than Microsoft DOS, without buying a Compaq PC.
> Both men knew why: Microsoft DOS had never been a true copy of PC DOS, as Gates had admitted to Canion during the development of Compaq’s first machine. The differences had only increased over time, as Microsoft’s deal with IBM prohibited the same developers working on both versions. Compaq had made its own version of DOS since the beginning. With its singular focus on 100 percent compatibility, the result was a product that was more compatible with PC DOS than Microsoft’s own product.
> Word was spreading among computer buyers that Compaq DOS was better. Even people who owned other PC clones were choosing to buy that instead of Microsoft’s own public version. This could have created friction between Compaq and Microsoft. Instead, Canion did something extraordinary. Compaq withdrew Compaq DOS from sale unless it was specifically bundled with a Compaq computer. He then licensed Compaq DOS back to Microsoft.
> From Gates’s perspective, this was an incredible deal. He was able to halt all internal development on Microsoft DOS, saving time and money. From this point onward, every version of Microsoft DOS he sold was, in fact, Compaq DOS, with the digital equivalent of its serial numbers filed off. All Canion asked in return was that Microsoft never release the very latest version of DOS that Compaq provided it until after a few months’ delay. This was to make sure that Compaq always had a slight advantage in compatibility over its rivals.
> Canion even agreed to Gates’s request that they keep the entire arrangement secret, to avoid souring Microsoft’s relationships with the other clone companies. It would remain secret for almost 40 years.
MS-DOS wasn’t a specific IBM PC OS, it was designed to be generic 8086 OS. It was up to the OEM to adapt the machine specific code (mostly in IO.SYS / IBMBIO.COM) to their system. IBM owned IBMBIO.COM, and some of the utilities like MODE and FDISK, and early on Microsoft didn’t have its own implementations to offer for people building generic PC clones. You had to write your own, and hope they were compatible. Microsoft did eventually offer a generic MS DOS with an IBM PC type IO.SYS and reimplementation of the utilities, so perhaps those are descended from Compaq’s versions?
As time went on and Microsoft started selling more and more copies of MS-DOS to manufacturers making PC clones, MS-DOS and PC DOS grew closer together, not further apart. MS-DOS 3.2 (1986) was the first version that Microsoft made available in a packaged form to OEMs that were shipping PC clones (it was still available as source code to OEMs who wanted more customization). For previous versions, OEMs were required to write their own versions of several hardware specific utilities (such as FDISK.COM and MODE.COM) that were originally written by IBM. MS-DOS 3.2 contained Microsoft-written clones of these utilities. MS-DOS 3.3 (1987) was written entirely by IBM (not Compaq!), as most of the key members of the MS-DOS team were busy working on OS/2. Because it came out after the Microsoft-IBM joint development agreement, Microsoft gained the rights to the IBM-written utilities and the packaged versions of MS-DOS 3.3 and all later versions shipped with the same utilities as their PC DOS counterparts.
The closest thing to the claims this article makes is that Compaq did in fact maintain their source code license to MS-DOS and made enhancements to their version. The most notable example of this is that Compaq DOS 3.31 introduced a modified version of FAT16 that supported partitions larger than 32MB. I assume Compaq licensed this functionality back to Microsoft, as there's versions of DOS 3.31 branded for other OEMs, and support for Compaq's modified FAT16 (known as FAT16B) was included in MS-DOS 4.0.
My understanding is that they had pitched the IBM PC compatible machine to TI and had been rebuffed - TI had its own mostly compatible PC offering and the no one in charge was willing to admit it was a mistake.
Trailer is https://www.youtube.com/watch?v=7wjJYqUkHd8
You can watch the documentary on Tubi https://tubitv.com/movies/559438/silicon-cowboys
os2museum.com was just recently able to trace how one particular DOS bug (more than two BIOS harddisk drives would make earlier DOS-versions hang at boot) was handled across different companies, and how and when exactly a fix made it into actual MS-DOS.
(Compaq had a fantastic reputation which they tarred with shitty consumer PCs. HPE still sells Proliants, and I'd guess they still use 'compaq screws'.)
Compaq's CEO at the time of the Compaq downsizing and eventual acquisition, Michael Capellas, is now the advisor to the company I work for. And the man who sold the Banyan Vines solution to Compaq in the 90's is now my boss.
> At a hotel room in Silicon Valley, in April 1989, Canion and Gates met with Andy Grove and Intel chair Gordon Moore to try to persuade them to stick with 486 development. After considerable back and forth, Intel reversed course. The new chip launched in late 1989.
Could this be the moment that forever saddled us (and Intel) with the cumbersome legacy of x86? It seems like a great cultural win for PCs in the moment, but in hindsight this decision almost feels backwards somehow.
Going to a computer shop on a random shopping mall, usually only a few gamer PCs are available as composable desktops, 90% of computers on display are laptops.
Servers are mostly designed for companies with racks or hyperscalers.
Most non technical people nowadays only have a smartphone and a tablet as computers, with the integration of all 8 and 16 bit home computers PC compatible were fighting against.
https://podcasts.apple.com/tr/podcast/compaq-computers-rod-c...