How CP/M Launched the Next 50 Years of Operating Systems (computerhistory.org) 80
50 years ago this week, PC software pioneer Gary Kildall "demonstrated CP/M, the first commercially successful personal computer operating system in Pacific Grove, California," according to a blog post from Silicon Valley's Computer History Museum. It tells the story of "how his company, Digital Research Inc., established CP/M as an industry standard and its subsequent loss to a version from Microsoft that copied the look and feel of the DRI software."
Kildall was a CS instructor and later associate professor at the Naval Postgraduate School (NPS) in Monterey, California... He became fascinated with Intel Corporation's first microprocessor chip and simulated its operation on the school's IBM mainframe computer. This work earned him a consulting relationship with the company to develop PL/M, a high-level programming language that played a significant role in establishing Intel as the dominant supplier of chips for personal computers.
To design software tools for Intel's second-generation processor, he needed to connect to a new 8" floppy disk-drive storage unit from Memorex. He wrote code for the necessary interface software that he called CP/M (Control Program for Microcomputers) in a few weeks, but his efforts to build the electronic hardware required to transfer the data failed. The project languished for a year. Frustrated, he called electronic engineer John Torode, a college friend then teaching at UC Berkeley, who crafted a "beautiful rat's nest of wirewraps, boards and cables" for the task.
Late one afternoon in the fall of 1974, together with John Torode, in the backyard workshop of his home at 781 Bayview Avenue, Pacific Grove, Gary "loaded my CP/M program from paper tape to the diskette and 'booted' CP/M from the diskette, and up came the prompt: *
[...] By successfully booting a computer from a floppy disk drive, they had given birth to an operating system that, together with the microprocessor and the disk drive, would provide one of the key building blocks of the personal computer revolution... As Intel expressed no interest in CP/M, Gary was free to exploit the program on his own and sold the first license in 1975.
What happened next? Here's some highlights from the blog post:
Kildall was a CS instructor and later associate professor at the Naval Postgraduate School (NPS) in Monterey, California... He became fascinated with Intel Corporation's first microprocessor chip and simulated its operation on the school's IBM mainframe computer. This work earned him a consulting relationship with the company to develop PL/M, a high-level programming language that played a significant role in establishing Intel as the dominant supplier of chips for personal computers.
To design software tools for Intel's second-generation processor, he needed to connect to a new 8" floppy disk-drive storage unit from Memorex. He wrote code for the necessary interface software that he called CP/M (Control Program for Microcomputers) in a few weeks, but his efforts to build the electronic hardware required to transfer the data failed. The project languished for a year. Frustrated, he called electronic engineer John Torode, a college friend then teaching at UC Berkeley, who crafted a "beautiful rat's nest of wirewraps, boards and cables" for the task.
Late one afternoon in the fall of 1974, together with John Torode, in the backyard workshop of his home at 781 Bayview Avenue, Pacific Grove, Gary "loaded my CP/M program from paper tape to the diskette and 'booted' CP/M from the diskette, and up came the prompt: *
[...] By successfully booting a computer from a floppy disk drive, they had given birth to an operating system that, together with the microprocessor and the disk drive, would provide one of the key building blocks of the personal computer revolution... As Intel expressed no interest in CP/M, Gary was free to exploit the program on his own and sold the first license in 1975.
What happened next? Here's some highlights from the blog post:
- "Reluctant to adapt the code for another controller, Gary worked with Glen Ewing to split out the hardware dependent-portions so they could be incorporated into a separate piece of code called the BIOS (Basic Input Output System)... The BIOS code allowed all Intel and compatible microprocessor-based computers from other manufacturers to run CP/M on any new hardware. This capability stimulated the rise of an independent software industry..."
- "CP/M became accepted as a standard and was offered by most early personal computer vendors, including pioneers Altair, Amstrad, Kaypro, and Osborne..."
- "[Gary's company] introduced operating systems with windowing capability and menu-driven user interfaces years before Apple and Microsoft... However, by the mid-1980s, in the struggle with the juggernaut created by the combined efforts of IBM and Microsoft, DRI had lost the basis of its operating systems business."
- "Gary sold the company to Novell Inc. of Provo, Utah, in 1991. Ultimately, Novell closed the California operation and, in 1996, disposed of the assets to Caldera, Inc., which used DRI intellectual property assets to prevail in a lawsuit against Microsoft."
My first PC (Score:5, Interesting)
Re:My first PC (Score:5, Interesting)
My first PC was a two-user CP/M M/PM PC. It had 64MB of memory per user
ITYM 64kB
The downfall of CP/M and M/PM was that the once again, standards were loose.
The downfall was that it was tied to a slow processor (not when it was new, but not so long thereafter) and it had no hierarchical file system which was already an expected feature of a real OS.
Something I posted on Gary and CPM here in 2014 (Score:5, Insightful)
https://tech.slashdot.org/comm... [slashdot.org]
I quote someone else saying: "The PC world might have looked very different today had Kildall's Digital Research prevailed as the operating system of choice for personal computers. DRI offered manufacturers the same low-cost licensing model which Bill Gates is today credited with inventing by sloppy journalists - only with far superior technology. DRI's roadmap showed a smooth migration to reliable multi-tasking, and in GEM, a portable graphical environment which would undoubtedly have brought the GUI to the low-cost PC desktop years before Microsoft's Windows finally emerged as a standard. But then Kildall was motivated by technical excellence, not by the need to dominate his fellow man."
And my comment on that included (removing all the supporting links): ... ... .. ...
"We had choices as a society. I saw some of them first hand in the 1970s and 1980s when I started in computing. I bought Forth cartridges for the Commodore VIC and C64. I worked very briefly on a computer with CP/M (although using Forth on it though). The OS choice pushed by the person born with a million dollar trust fund who "dumpster dived" for OS listings won (who did little of the development work himself) -- with an empire built on QDOS which has shaky legal standing as a clone of CP/M which is probably why IBM did not buy it itself. And we were the worse for it as a society IMHO.
But that problematical path would not have been possible without political and legal decisions to base the development of computing around the idea of "artificial scarcity" via copyrights and patents which set the stage for that. We still have choices, and we can still pick different ways forward. [With] the free and open source software movements, we are in a sense returning to older ways of sharing knowledge that were more popular before artificial scarcity was so broadly thought to be a good idea for promoting progress. One should always ask, "progress in what direction"?
Bill Gate's could have spent his lifetime writing free software. That being born a multi-millionaire was not enough for him is a sign of an illness that causes "financial obesity", not something to be emulated. But, in the end, it is not Bill Gates who has destroyed our society as much as all the people who want to be the next Bill Gates and support regressive social policies they hope to benefit from someday.
Those who have the impulse to share and cooperate more than hoard and compete are still stuck trying to navigate the economic mess we have made of today's society through artificial scarcity, the growing rich/poor divide, the diversion of so much productivity into weapons and consumer fads, and so on. The late 1960s and early 1970s when Kildall, Moore and Kay/Ingalls were having their breakthroughs were a more hopeful time in that sense.
Still, the web and HTML5/JavaScript/CSS3 are a new hope for sharing via open standards, and they have been a big success in that sense. I'm moving more of my own work in that direction for that reason (even for all their own issues). Like has been said about JavaScript -- it is better than we deserve considering its history and the pressures that we all let shape it."
So, while you and others who are posting here are no doubt right on technical limits and marketing issues, I would say the "downfall" story is more complex socially than one man and his decisions with one design.
I'll again echo a key point about Gary by someone else quoted at the start: "But then Kildall was motivated by technical excellence, not by the need to dominate his fellow man." We need to build a society and an economy where people who make that choice get more support and respect.
Re:Something I posted on Gary and CPM here in 2014 (Score:4, Insightful)
I think the story is proof that design doesn't matter. People will buy garbage if the marketing is good enough. You have to have a good product AND good marketing to beat a bad product. Just look at every major purchase you've done in the last 20 years - cars, appliances, TVs etc.
Re: (Score:3)
What is best for society is often in this same vein. You can profit yourself, or you can create for the
Re: (Score:2)
Re: (Score:2)
Incidentally, MS-DOS 1.x/PC-DOS 1.x was very CP/M like. MS-DOS 2.x started adding more traditional operating system conventions that Microsoft adopted from their Xenix. In that in CP/M, and DOS 1.x, files specified on the command line were opened for you by the operating system and you basically manipulated pointers and asked the OS to bring it into memory. DOS 2.x later acquired the more traditional open/read/write/seek/close style semantics and system calls.
DOS 1.x was similar enough to CP/M from programmer's POV, due to CP/M APIs being copied into DOS. Visually though, DOS 1.x looked like all subsequent versions of DOS. DOS 2.x was infused with features ported from Unix, but it retained its CP/M legacy (notably, FCBs and APIs supporting FCBs), and these persisted all the way until Windows 98 and 32-bit Windows 10.
Neither CP/M nor DOS "open" files whose names are specified in the command line. What happens is that both systems fill unopened FCBs with these fil
Re: (Score:2)
ITYM 64kB
ITYM 64 KiB
64 kB = 64,000 bytes
64 KiB = 65,536 bytes
Re: (Score:3)
ITYM 64kB
ITYM 64 KiB
64 kB = 64,000 bytes
64 KiB = 65,536 bytes
Back then, KB was all binary ... ...
"The term 'kilobyte' has traditionally been used to refer to 1024 bytes
The binary meaning of the kilobyte for 1024 bytes typically uses the symbol KB, with an uppercase letter K
In December 1998, the IEC addressed such multiple usages and definitions by creating prefixes such as kibi, mebi, gibi, etc., to unambiguously denote powers of 1024"
https://en.wikipedia.org/wiki/... [wikipedia.org]
Hence, anything built before 1998 should use the nomenclature in place at that time. Maybe.
Re: (Score:2)
...such as kibi, mebi, gibi, etc., to unambiguously denote powers of 1024....
Those prefixes invoke images of Liberace and Elton John in their flaming gay attire.
Re: (Score:2)
My first PC had an Intel 8080 CPU and had 64 KiB of RAM (in those days called "64K" because people were stuck in the mindset of small powers of two back then, and it just so happened that 2^10 is close enough to 10^3 that nobody much cared; the notion of a gigabyte or a terabyte was decades in the future).
Re: My first PC (Score:2)
My third had it (Score:2)
Another version (Score:1)
The version I heard 20 years ago had Microsoft stealing source code from Digital Research, not "copying the look and feel of the DRI software" ...
Re: Another version (Score:5, Informative)
And in reality neither happened
Microsoft bought a port of cp/m for x86 from an independent company cause DRI and Gary were off being themselves and couldn't be arsed to support the new Intel architecture
Re: (Score:2)
I've used CP/M, and indeed there are a lot of similarities to DOS.
Gary could have been as big as Gates if he didn't make a few missteps.
Re: Another version (Score:4, Interesting)
I've used CP/M, and indeed there are a lot of similarities to DOS.
Gary could have been as big as Gates if he didn't make a few missteps.
He seemed to be more of the photo-nerd who was more interested in what the tech can do than creating an empire. He went on to do a number of neat things, such as some early CGI:
In an oral history for the Computer History Museum, Brian Halla, Intel's technical liaison to DRI, recalls that Gary "showed me this VAX 11/780 that he had running in his basement, and he was so proud of it, and he said, 'I figured out a way to have a computer generate animation,' and he said, 'Watch this. And he runs a demo of a Coke bottle that starts real slowly and starts spinning, and so as maybe several months went by, he lost interest in this, and he sold his setup to a little company called Pixar.'"
To me, that story shows him to be more of the "what can it do" rather than "what is it worth." Had he had his Steve Jobs to his Steve Wozniak, he probably wouldn't be an historical afterthought. Interestingly, at one point he had the trademark to the term Mac.
Re: (Score:1)
Re: Another version (Score:2)
Like getting into bar fights with hells angels members ... that was a noble move
Re: (Score:2)
Microsoft bought a port of cp/m for x86 from an independent company cause DRI and Gary were off being themselves and couldn't be arsed to support the new Intel architecture
I'd imagine they didn't want CP/M more splintered than it already was. The same thing ended up happening to MS-DOS. There was a version for Zenith computers incompatible with the version for the IBM-PC. Same with the Tandy portables and initial desktop PCs, and ITT, Olivetti, TI, HP palmtops, etc...
Re: Another version for Zenith (Score:2)
The Zenith Z100 had ZDOS. It was mostly compatible. I ran Turbo Pascal and many other PC programs on it. There was a software emulator called ZPC that remap PC's RAM layout to the 768k the Z100 had to get graphic working.
The Z100 had an 8088 and an 8085 with a S100 bus. The graphics was 640x225 with 8 colors. There was an interlace mode that could do 640x500. It flickered unless you had a CRT with long persistent phosphors. The keyboard had 13 function keys (F0-F12) a dedicated help key, a number keyp
Re: (Score:2)
I'd imagine they didn't want CP/M more splintered than it already was. The same thing ended up happening to MS-DOS. There was a version for Zenith computers incompatible with the version for the IBM-PC. Same with the Tandy portables and initial desktop PCs, and ITT, Olivetti, TI, HP palmtops, etc...
Actually, there was a version of CP/M for almost every Intel 8080/8085 or Zilog Z80 computer, and more often than not, these versions were incompatible to one another too... DRI happily let OEMs customize CP/M for their hardware, and this was DRI's business strategy. SCP with their QDOS/86DOS and later Microsoft with MS-DOS were doing basically the same thing. As a result, CP/M was just as splintered as the early versions of DOS. Later, when PCs converged to being all IBM PC-compatible, DOS started being mo
Re: (Score:2)
My roommate worked on a project with the guy who wrote most of QDOS, which was one of scores of CP/M clone operating systems out there. Peter asked him if he thought Gates had ripped them off, and he said, "No, that's about what it was worth as an OS."
Re: (Score:2)
My roommate worked on a project with the guy who wrote most of QDOS .... Peter asked him if he thought Gates had ripped them off, and he said, "No, that's about what it was worth as an OS."
The guy who wrote QDOS was Tim Paterson while working at Seattle Computer Products, so is that who you mean? Paterson was afterwards offered a job (=poached) by Microsoft as the main guy who ported QDOS (by then renamed 86-DOS) to the IBM PC, so perhaps he did not have the most unbiased view. Anyway, Microsoft did later pay SCP an additional sum of money out ot court because they had misrepresented why they wanted to buy DOS from them.
Re: (Score:2)
Couldn't remember his name, but yeah, that's him. There were a **LOT** of companies and individuals who were rolling-their-own operating systems at the time, some of those folks are still here on SlashDot. Almost certainly there were better ones available out there, but SCP was in the right place at the right time, and Gates (or maybe Myrvold? I forget now.) knew someone who worked there. FWIW, according to Peter, Paterson said QDOS stood for Quick and Dirty Operating System.
Re: (Score:2)
Couldn't remember his name, but yeah, that's him. There were a **LOT** of companies and individuals who were rolling-their-own operating systems at the time, some of those folks are still here on SlashDot. Almost certainly there were better ones available out there, but SCP was in the right place at the right time
Maybe there were better OSes, and there were better OS creators than Tim Paterson, but OSes for Intel x86? There was not a whole lot of them. And do you know why? Nobody writes an OS if there is no hardware where such OS can be run, and there simply were virtually no x86 computers on the market, except some Intel development systems, which had some rudimentary Intel-created software, but were rather expensive and not very user-friendly. The hobbyist personal computing market was dominated by S-100 designs,
Re: (Score:2)
SCP (the company that created DOS) just had to have some OS for Intel 8086/8088, if they wanted to survive. The main business of SCP was making S-100 boards, and they were investing heavily in 8088 CPU boards. Nobody would buy them without at least a promise that an OS was coming... DRI wasn't interested in helping, so SCP took the matter in their own hands, cloning CP/M to create QDOS for 8088. At this time they were doing this only to sell their hardware, not to dominate the world.
Re: (Score:2)
I suggest, if you have time, you may want to watch it.
Re: (Score:2)
The version I heard 20 years ago had Microsoft stealing source code from Digital Research, not "copying the look and feel of the DRI software" ...
And this is a long-lived hoax, perpetrated by some sci-fi authors (J.P.) and other folks who didn't know what they were talking about.
You see, right now full source code for CP/M 2.2 (presumably the version which MS stole code from) and DOS 1.1 is available. Everyone can check for themselves that there is no stolen code and this hoax is, well, a hoax. But even in the past, both these systems were small enough so disassembling them was feasible.
This was tested in court, by the way, and experts were consulted
I'm not old enough to remember CP/M, but... (Score:4, Informative)
I certainly remember Gary Kildall from Computer Chronicles along with Stewart Chifiet. They did a great job of demonstrating the early PC revolution to people on their PBS show.
The entire backlog of that program is available on YouTube if you're interested.
Youtube Computer Chronicles is stolen content (Score:4, Interesting)
Re: (Score:2)
Re: (Score:2)
Yeah, YouTube seems to have the entire catalog of episodes, and they looked like they were ripped from the station masters. Who did that?
Re: (Score:2)
Re: (Score:2)
Re: (Score:1)
What happened next (Score:5, Interesting)
CP/M was written for the Intel 8080. Other manufacturers came out with other CPUs on a chip and other operating systems, most famously for the Apple 2. They were 8 bit data, 16 bit addressing chips.
Then the 16 bit chips started showing up, the 8086, the Z8000, and the Motorola 68000. IBM took the least of these and released a PC. It wasn't much, but it had the name IBM on the side so a lot of people bought. IBM also did something else that a lot of people thought was very strange. They didn't stop other people from making and selling cheap clones of their PC. So even more people bought the clones.
IBM had decided to purchase an operating system for their PC from Bill Gates' company, Microsoft. There's a lot of stories around that decision because apparently Gary Kildall had written a version of CP/M for the new processor also. The popular account is that IBM executives came to see Kildall but he was out flying and this got them miffed. Another story is that Bill Gates' mother was working a charity event and there was an IBM executive there who told her IBM was shopping for an OS and she passed that on to her son who went out and bought an OS from somebody else cheap and licensed it to IBM, keeping the right to also license it to the clone makers. He also vigorously went after anyone who tried to pirate and sell his software. Gates seems to have been much more focused on the money side than the other pioneers of the revolution.
Re: What happened next (Score:5, Informative)
They didn't stop other people from making and selling cheap clones of their PC
As I recall, they had enabled everything to be done freely except the BIOS. They thought the BIOS would be a lock on the core platform, but enjoy a rich ecosystem of peripherals and suppliers. When companies cloned the BIOS, they did try to sue. Think it became quickly obvious that clean room cloning of the BIOS was too easy and nothing illegal about that.
Re: (Score:2)
Think it became quickly obvious that clean room cloning of the BIOS was too easy and nothing illegal about that.
From what I remember the original IBM PC only had a few dozen BIOS calls and some bootstrap stuff. Not sure why they thought that would be an insurmountable hardship for competing manufacturers to overcome.
Re: (Score:2)
I can only speculate, but:
-I had heard that the IBM PC effort wasn't exactly fully supported by the wider IBM, so they had to make do and potentially might have had to be willfully overly optimistic to rationalize their plan to have so much of the system defined by freely implementable standards
-They might have hubris that BIOS was 'hard', at least the business leadership I could easily imagine thinking that, and no one is going to second guess them.
-They might have assumed copyright would have protected th
Re: (Score:2)
I can only speculate, but: .
-I had heard that the IBM PC effort wasn't exactly fully supported by the wider IBM,
I had heard that one of the reasons IBM never really fully supported the PC was that they thought of it as a hobbyist curiosity, rather than something to be fully supported like their minicomputers and mainframes. (In my first workplace, even in 1990 there was an original 1981 vintage IBM PC in one office, along with a 1984 IBM PC/AT. in another office Both included the manuals which assumed that all the peripheral cards would have to be installed by the user, rather than being pre-installed at the factory.
Re: (Score:2)
CP/M was written for the Intel 8080. Other manufacturers came out with other CPUs on a chip and other operating systems, most famously for the Apple 2. They were 8 bit data, 16 bit addressing chips.
My CP/M system was one of these. I had a Franklin Ace with a Z80 coprocessor in it. Had colleagues that had Osbornes so I had access to all their software. Those were the days.
Re:What happened next (Score:4, Informative)
[...] the 8086, the Z8000, and the Motorola 68000. IBM took the least of these and released a PC.
I'm sure you know this, but it was actually the 8088 that was in the first IBM PC, not the 8086. The 8086 didn't appear in an IBM system until a couple years later—the PC/AT.
Re: (Score:1)
Yes, I knew. I was being a bit lazy not mentioning that, so thanks for calling me out. I've posted at greater length about those days in the past, but I was trying to keep it short this time.
Re: (Score:3)
[...] the 8086, the Z8000, and the Motorola 68000. IBM took the least of these and released a PC.
I'm sure you know this, but it was actually the 8088 that was in the first IBM PC, not the 8086. The 8086 didn't appear in an IBM system until a couple years later—the PC/AT.
The PC/AT used the 80286. It was some of the clone machines that used 8086 instead of 8088 (The Amstrad PC was one of these, if memory serves)
Re: What happened next (Score:3)
I don't remember if the xt machines from IBM used the 88 or the 86 but ya PC is 88 AT is 286
Re: (Score:2)
Yep, we had an Amstrad PC-20 when I was growing up. 8086, 512k of RAM, CGA, and a 720k floppy drive. It also came bundled with a version of DRI's GEM :)
Re: (Score:2)
In fact, the 8086 didn't appear in an IBM system until 1987 (IBM PS/2 model 30).
Re:What happened next (Score:5, Interesting)
... Gates' mother was working a charity event and there was an IBM executive there who told her IBM was shopping for an OS and she passed that on to her son who went out and bought an OS from somebody else cheap and licensed it to IBM
For the record, he bought it from Seattle Computer Products. Also, his mother and the IBM exec didn't just meet at event, they were committee members of the same charity.
There is also the story that (because of Mum) IBM approached Gates before they approached Kildall, and Gates recommended Kildall and CP/M because Microsoft had only done apps and a BASIC interpretor before. But Kildall and/or wife pissed IBM off, so IBM returned to Gates and asked if he had any better ideas. In the meantime it had occurred to Gates that he could buy 86-DOS from SCP and parcel up as Microsoft's own. So he sold IBM something he didn't yet have*.
It all goes to show that the IBM execs knew f-all about micros and what they were buying into, and didn't take the PC idea seriously anyway.
* This "brainwave" of Gates is one of the things that makes some people think he was a genius. However, people in the wholesale trade sell stuff they don't own yet all the time.
Capitalism FT[W|L]??? (Score:2)
Yeah, I think Bill Gates was closer to a combo of Woz and Jobs than people realize. At least enough of a Woz to recognize good vs. bad technology, and to come up with methods/tools to create lots of profit for himself with it.
IBM confuses me... My dad back in the 80's and 90's was learning and working on mainframes still from them. I wonder if their focus was just too spread out? That they didn't see much profit possible for home computers AND they hamstrung their own efforts by charging more than they
My first "OS" (Score:2)
Thanks Alan Sugar!
Re: (Score:2)
I remember CP/M on the CPC6128, but the only thing I used it for was to boot Logo. My real debt of gratitude to the Amstrad computer team is for the manual, which I used to teach myself BASIC.
Re: (Score:1)
You probably also booted it to run the disc formatting software.
But yes, the manual was very good, also the magazines with their type-ins.
Re: (Score:2)
I had a cpc464, so no cpm on that one, but i upgraded to the pcw which did come with cpm and 512kB of ram and 2 drives!
Those were the days (Score:2)
Wasn't Kildall the guy who blew off IBM? (Score:2)
I remember reading that the reason that Bill Gates got the contract with IBM to write the OS for their PC line was that Gates actually met with IBM staff and showed them around the Microsoft offices and was very interested in getting the contract. One of his competitors blew off meeting with IBM because he had vacation scheduled and his attitude was something like "Hey IBM. You can talk to me after I get back f
Re: (Score:2)
Re: (Score:2, Informative)
Mrs. Gates was on a charity board with an IBM exec and initiated contact with IBM... it's who you know and having a family rich enough to get lucky connections like that.
Then Gates defrauded IBM but saved himself by finding an OS to buy cheap and adapt; probably unable to buy CP/M and I'd like to hear the story of how he failed to buy that instead of the shit OS he did buy...
Fond memories (Score:4, Interesting)
This brings back fond memories of my first, home-built, computer from 1982: the Ferguson Big Board [wikipedia.org], running CP/M.
CP/M unexpectedly found on Amstrad Word Processor (Score:5, Interesting)
When I was in college in the late 80s, I purchased an Amstrad PCW-8256 Word Processor, and it was a Godsend, making writing term papers a breeze over typewriters. It had the competing and ultimately passed over 3" (not 3.5") floppy drive, and it performed extremely well. I didn't realize when I purchased it that it could also boot into CP/M, opening up the ability to run games, third-party software, and programming. Offerings were limited, but it opened some otherwise unknown doors, helping me in my eventual career in IT.
Re:CP/M acronym (Score:4, Informative)
does NOT stand for Control Program for Microprocessors.
the M means something else. Thats why the slash / I leave it to the researcher to research.
You're partially correct. Originally it stood for "Control Program/Monitor" but somewhere down the line it changed to "Control Program for Microprocessors".
As for the / in the name, PL/M stands for "Program Language for Microprocessors" so...
Re: (Score:3)
PS/2 = "Personal System for Two?"
Sounds romantic!
Re: (Score:1)
Re: (Score:3)
does NOT stand for Control Program for Microprocessors.
the M means something else. Thats why the slash /
I leave it to the researcher to research.
That's what it came to mean later, substitute "microcomputers" for "microprocessors". But originally CP/M stood for "control program / monitor". Monitor was a fairly standard term for a primitive operating system.
It started becoming "control program for microcomputers" after PL/M, which stood for "programming language for microcomputers."
my first homebuilt computer (Score:3)
Re: (Score:2)
ComputerLand (Score:4, Interesting)
I worked at one of the early ComputerLand stores back in the late 70's as their hardware technician. It was a challenging job because nobody there had any prior experience with the machines including me. People were fascinated with the computers though and there was a lot of foot traffic. We struggled to answer questions, including "what can you do with them that's useful".
We sold a very expensive "business-oriented" box that ran CP/M. I can't remember the brand and it is long gone, but you could get 8" floppy drives for it and that made it special. There was a rudimentary suite of office software that could run on it, word processing and some simple book keeping. I installed a handful of them at office sites. Just figuring out how to hook up a printer was a major feat. You couldn't buy pre-fabricated printer cables, I had to make them.
Re: (Score:2)
Waves from an ex-Egghead assistant manager
I miss the days when software came in plastic bags and brown cardboard boxes, sold on wooden bookcases lit by quartz lights.
Furthermore, I miss a somewhat bad rendition of Vivaldi's Four Seasons playing on infinite shuffle.
And I miss local, home-grown software. There was an unofficial addon to Spectrum Holobyte's Welltris sold in San Jose called Mouse Commander with a black and white logo of a mouse sitting on a tank amongst Tetris-like pieces that added mouse i
Re: (Score:2)
>> sold on wooden bookcases lit by quartz lights
Your store sounds more boutique than ours but I can definitely picture it.
Looking back on it, the machines of that era were amazingly expensive for what they were. A basic dot matrix printer would go for about $220 which is more than $800 in today's money. An Apple II with 48k RAM could easily cost $1,200 which is $4,500 today. People bought a fair number of them though.
Re: (Score:2)
omg WELLTRIS -- I had forgotten that even existed. So many hundreds of hours of adolescence wasted perfecting a skill that has brought zero value to my life other than once every 4-5 years when I'm helping someone pack a Uhaul.
Set file systems BACK 50 years (Score:4, Interesting)
CP/M is proof that shitty file system design (stupid 8.3 filenames) can have far lasting changes. Even today in Windows 11 we can't name a filename with a colon (:) due to the dumb decision of using colon to designate a drive instead of Unix's consistent and beautiful nomenclature to refer to devices with slashes.
My Apple 2 had 30 character filenames (WITH spaces) and using CP/M + Microsoft's Z80 SoftCard [wikipedia.org] + Wordstar felt like a downgrade.
I still love Apple poking fun [noone.org] of MS blindly copying dumb features:
C:\ONGRTLNS.W95
At least MS was smart enough to use a recycle bin instead of a trash can.
Re: (Score:2)
C:\ONGRTLNS.W95
At least MS was smart enough to use a recycle bin instead of a trash can.
I miss those days when Apple played the upstart card with funny ads.
Those were the days.... (Score:2)
I sure do miss my Kaypro II.
I was working with analog and digital computers running flight simulators for the Air Force so I got my computer fix at work. As a result, I got into the "PC" craze a little later than some of my compatriots.
My biggest problem was as an airman I had little money left over for the likes of an Altair when they came out. By the time the Kaypro came to my attention I was a sergeant and had a little more disposable cash for buying my own computers to play with.
I sure do miss those day
Correction: How DEC OS/8 lead to CP/M and DOS (Score:2)
H19 (Score:2)
The machine I had was a HeathKit H19. This had it's own OS called HDOS. Not sure what the quality of that was or how it compared to CP/M. However the hardware also had ROM mapped to the first 2K or so (to run the program controlling the front panel display) which made it incompatible with CP/M. I somewhat remember it was already clear that all the good software was only for CP/M and I had the wrong machine and HeathKit screwed up. Anybody else remember these, have any comments on them? It does sound like cr