#DOScember

[@Operation8Bit]

We've gotten a lot of great feedback on MS-DOS windows managers that provided multitasking capabilities for IBM compatible PCs. If you would like us to do an episode on these, hit the thumbs up on this comment.

[@NoelsRetroLab]

Great, informative video! I never heard of Concurrent DOS, but I remember using something, maybe it was DESQview along with QEMM to do multitasting with MSDOS on my 386SX. As a matter of fact, I remember running my local university BBS in the back while I would play Space Quest. Whenever somebody would log in, I would occassionally flip over to the BBS one to see what they were doing 😃 Fun times!

[@Operation8Bit]

Thanks Noel. I vaguely remember DESQview, and it did come up when I was researching this video. I was thinking that it taking a look at it might be interesting to do a follow up to this episode.

[@NoelsRetroLab]

@@Operation8Bit Oh that could be fun! I remember being pretty happy with it back in the day. Also, I believe it ran on "top" of MSDOS instead of being a separate OS, but I could be wrong. It's been a while.

[@1697djh]

MAPLIN used concurrentDOS/386 on there 1980's/90's EPOS system, with terminals as cash registers

[@Caseytify]

Yes, it was called DesqView/386, and featured interrupt-driven multitasking. One of the major flaws with Windows 3.x is that it used cooperative multitasking, which is terrible if you're running a BBS in the background. This is why OS/2 was so popular among Fidonet sysops. The problem is that in order to maximize window memory size, it needed to load all drivers first. Even with load high, once you've loaded the sound card driver, the mouse driver, and so on, you were looking at 630K memory. That's the biggest window you could open. DesqView/386 used many Topview conventions, including the ability to cut & paste between well-behaved programs. You could even run Windows 3.x in real mode, IIRC. It was fun sometimes to switch over so I could play Solitaire. :) There were other requirements, like using 16550 UARTS and a FOSSIL driver, but that still allowed a great deal of freedom for the sysop. I started with Opus BBS and later migrated to MAXIMUS BBS. After running into memory issues, I knew I had to upgrade one way or the other. OS/2 was massively superior to W95, but the latter was cheaper. When I heard that IBM was charging for their development kit, while Microsoft was literally giving theirs away for free, I saw the writing on the wall. Bought 4 more megs of memory & a CD-ROM kit. A whopping 2x speed! No, I was not about to load Win95 via floppies! Once I integrated my new hardware I was running a 486dx2-66 with 8 Mb of ram. One of the cool things about Win95 is that NT console apps would work as is, so all I had to do was drop in the NT executable for MAXIMUS and it worked flawlessly. ... Some of my regulars could tell that I was playing Quake locally, as there would occasionally be long pauses when they were online. Never dropped any data, though.

[@matth.imaging8952]

Nice to see this. I used Concurrent DOS 386 for a few years in a software development environment, writing software in Turbo Pascal and Assembly for the Z80 and 6809 CPU using cross assemblers. Also still have it running on a vintage IBM L40SX laptop. I also installed CDOS 386 on a VM (using Virtual Box) on my current computer, just for fun ;-)

[@svensubunitnillson1568]

4 Gigs of memory on a 386 wow, must have cost half a city block back in the days :)

[@tstahlfsu]

Great show and great channel! Thanks for tagging this with DOScember -- it's how I found you!

[@Operation8Bit]

Awesome! Thank you!

[@RetroTechChris]

Nice! Never heard of this before, made for a really interesting watch!!

[@Operation8Bit]

Glad you enjoyed it! I've seen some of your videos lately and this seems something right up your alley. I wonder if we could get it to boot on one of those HP Thin Clients you were showing the other day?

[@RetroTechChris]

@@Operation8Bit challenge accepted!! I'll give it a shot :-)

[@Operation8Bit]

@@RetroTechChris Ping me and let's discuss. [e-mail]

[@simpleprogrammingcodes]

Very interesting episode. I'm glad I discovered this channel. I hope you will continue.

[@punboleh7081]

That brings back memories :) Unfortunately I was stuck on a 286 at that time, so I never got beyond task switching (which didn't work very well with graphic programs, somehow they always ended up in the wrong graphic mode when switching back to them). It's only vaguely related to your question about DOS window managers that provided multitasking, but have you ever come across TEMPEST? It was a Dos Shell replacement by some OEM, but seems to have completely disappeared. I've only seen it mentioned in one book description that is said to come with a copy of Tempest. I've used it a lot back then, and now I can't even remember what it looked like.

[@quincy1048]

like you I used concurrent DOS for a speciality business application. We started with the 286 version and put 286 Rampage EMS cards into the box for up to 8meg of memory. That was pretty cool back then. We developed our applications in MT Pascal. I got assigned to OS support for the company back then because for some reason...I was too green to see the pain coming. I got to assemble and modify the OS to do things like bring in updated device drivers etc. The assembly took a couple hours and you had no idea if it was going to work. But the pascal development for the drivers for the process control application the company developed was pretty cool to work on. Yea the fun of a first software development job the year was 1988...I also participated in porting a bunch of there stuff to OS/2...yea you can imagine how that worked out...But the President thought with IBM involed that was going to Rock it...yea I moved on pretty quick.

[@debatabletruths6687]

CDOS, now that's a real blast from the past.

[@stephencole9289]

I knew Concurrent Dos well, as worked as a software Engineer at Digital Research (in the UK) at the time, and was there for the birth of Concurrent Dos 386

[@stephenpalmer9375]

My first job in IT was supporting ICL DRS300s that were running a flavour of CDOS. Happy days :)

[@lawrencedoliveiro9104]

4:30 By the way, if you want to delve into details, reference docs are available at Bitsavers: bitsavers.trailing-edge.com/pdf/digitalResearch/concurrent/ .

[@F4LDT-Alain]

The internal release of Microsoft MS-DOS 4.0 was a similar product, multi-tasking MS-DOS with virtual text consoles. I was using it when sent to Bellevue by a French PC manufacturer (Goupil) to evaluate it as a possible base for a non-dedicated file server offer. At that time MS Networks required a dedicated server.. Only IBM had a modified version that could run as a DOS background task in the same way the print spooler did. This MS-DOS 4.0 has never been released. One main reason being that there was not enough conventional memory left for it to be really usable. Windows' START command was introduced in that version of MS-DOS and still exists today.

[@lawrencedoliveiro9104]

7:34 Was the installer not running under the multi-tasking OS itself? Like when you are running the installer for a Linux distro, it is itself running under Linux, so it is easy to switch to a command shell to resolve any issues, and get back to the installer screen without having to reboot.

[@Operation8Bit]

Stay tuned... we have a follow up coming out soon that digs into the details. SPOILER!!! We also have got it all worked out... but you have to wait to see how ;-) (Yeah, we're assholes. But we needed to bring in some outside help and there is more sausage making in the works getting that all coordinated)

[@lactobacillusprime]

I've seen people running BBSes use this back in the day. I'd all forgotten about it until I saw your video :)

[@Operation8Bit]

Interesting, do you remember if they set it so that they could use multiple modems?

[@Keeping_IT_Simple]

New subscriber....from another channel Doscember recommendation amazing channel, sorry its taken me so long to find it ! great in depth technical knowledge & background presented extremely well - fantastic sense of humor as well, What more could an old tech person like me want?? Except maybe some of those sausages!! Keep up the Great Work Stay Safe TTFN PS Yes we do want to hear you what you are saying!!!

[@Operation8Bit]

Thank you for subscribing and thank you very much for the great feedback! 🙂 We're taking a short break for the holiday and the plan is to get back to the sausage making after Christmas. PS: Not sure Sparky would agree with you, he has to listen to me for hours 😂

[@cheater00]

Hey dude, really nice video! I appreciate you!

[@Operation8Bit]

Hey, thanks! 😃🍹

[@cheater00]

@@Operation8Bit yw :) keep em coming!

[@rgneave]

The memorys, worked as a multiuser dos engineer for many years ended my career working with IMS Real 32 that was a 32 bit multi-tasking system with fat 32 support. I used wize 120 and Windows 9x terminals had around 64 all over the country connected with phone lines and over internet. Still got a full set of disks and networking addons I can work it with my eyes closed great business operating system in its day

[@JamesGood]

Cool. I used Real 32 for years, we built a flight planning system for the airlines, on it. Was great!

[@wizdude]

Back in the 90’s I used to do support for a video library rental chain here in Australia. We used concurrent dos at each of the locations. The primary machine at each site ran the video library rental software and it would have a stallion multi port serial board used to drive a bunch of other Wyse 60 terminals. It all worked surprisingly well and it was a good solid platform.

[@JohnDlugosz]

I used "Back & Forth" for running multiple programs. It was compatible with no problems because it actually ran only one at a time, but let you switch between different images.

[@lawrencedoliveiro9104]

3:16 I also have a Jupyter notebook session (useful as an advanced graphing calculator). And a couple dozen terminal tabs open.

[@konradstrachan]

Half a dozen tabs, ha! Those are rookie numbers. New subscriber, looking forward to seeing more of your content in the future :-)

[@Operation8Bit]

Yeah I know right? I have a coworker that did a screen share the other day, and he had 4 browser windows and each of them had to have at least 20 tabs each. That guy is a pro! Thanks for the sub! :-)

[@retroretiree2086]

HI, Subbed because it made you subscriber count 888 :) Also I first saw this O/S as Concurrent CP/M in about 1984. I implemented our external HDD for it. The version I used was for the Apricot range of machines. Somewhere I still have the source for it supplied to my then employer by Digital Research!

[@Operation8Bit]

Wow, that's very cool! What was it written in? Assembly? And thank you very much for the for the sub... 888 is a great number! (I wish YT had a way to upload an image to the comments, I would post it)

[@retroretiree2086]

@@Operation8Bit Hi, Yeah, all assembler. Not sure if it was MASM or pure ASM. I certainly used MASM a lot back then. I've forgotten probably 90% of it :(

[@Operation8Bit]

@@retroretiree2086 I never learned ASM back in the day, my buddy Scott did a lot of bit twiddling in MASM and he tried to teach me but it never took. However, I've picked up a bit of 6502 Assembler over the past few months just for fun.

[@retroretiree2086]

​@@Operation8Bit I never did any 6502 there were a couple of other guys in the same company who did. I did Z80, 8086 and 68000. I mostly wrote device drivers for FDDs & HDDs for quite a lot of the different systems that were available back then.

[@stuartcastle2814]

Fairly certain I used this when I was much younger. The company I used to work for had an IBM AT and a Wyse Terminal connected to it. It also had a daisy wheel printer (that was actually made by Centronics). I'm fairly certain this AT was running Concurrent DOS. The OS was fairly well buried beneath the custom software the computer ran, with no need (in day to day use) for us to see a command prompt, but I am certain that Digital Research and/or Concurrent DOS were shown in at least one copyright message on restart. This is all assuming I am remembering correctly. Even assuming the company is still trading (which is unlikely, I was made redundant due to cashflow problems), they would likely have replaced the computer by now (this was the early 90s), so it's not like I can really check.

[@DrDavesDiversions]

Nice topic - I didn't know about this OS!

[@Operation8Bit]

Thanks Dave. Not many people did, which is why I thought it would be a fun (and different) topic. 😀

[@MartinAncher]

I think multitasking worked on MSDOS 4 in DosShell even on my 80286. It made use of swap file in DOS, so it was very slow to swap between applications. Maybe you could check it out in a later video.

[@Operation8Bit]

Based on the feedback in the comments, we've been thinking about a follow up that covers the multitasking apps available for DOS, this is definitely one to add to that list. It should be noted (because if I don't someone else will :-), DOS Shell was more of a task switcher and didn't have true multi-tasking capabilities. Thanks for the feedback!

[@u9vata]

Hmmm. This really looks awsome for productivity! I pretty much use DWM window manager on linux in the same way: fullscreen apps on their own virtual screen and win+numbers to change between them!!! Wondering if DWM devs maybe have seen concurrent DOS back in the days, because it is so similar, except that it is not at the bottom but at the top of the screen lol 🙂

[@perfectionbox]

I remember running Business Basic Extended apps on Multilink, but getting it to work with extended/expanded memory was too painful. Eventually gave up and switched to Xenix, which worked great.

[@wskinnyodden]

Used DR-MultiUser DOS with a serial port expansion board for 16 serial ports and then quite long (expensive) serial cables to connect to the cheapest XTs we could find to run as dumb terminals. And proper graphics support on serial terminals NEVER worked for me, though I did not really try hard truth be said. This was the Database server (build over Clipper/DBase) for the Invoicing and Stocks software my then boss was the main developer for. Can't say enough how much I loved migrating the whole shebang to a Novel Netware 3.12 based server at the time (which was in fact the first network and server fully configured by myself). That said, DR-Multiuser DOS were it not the lack of any Advanced Graphical support was a quite nice solution.

[@easybubbles6366]

Hi, I'm from the future. I need those 4 gigs of memory back please. I mixed those one up, they're megs. Sorry for the crappy performance. Don't worry, I'll fix this. See You in the past

[@xmaniac99]

Quarterdeck Sidekick -> Desqview Pro -> DesqView 386 -> Desqview/X

[@Caseytify]

I actually bought Desqview/X, but it never caught on.

[@lelandclayton5462]

I remember updating a bunch of PAR POS Terminals from C-DOS 386 to Real/32. I had a copy of Real/32 and it's an odd multi-user DOS, I think you could run eight programs at a time. With enough RAM you can run Windows 3.x as a DOS program session.

[@ChrisPollitt]

Some interesting history. Thanks!

[@Operation8Bit]

Glad you enjoyed it

[@xheralt]

I seem to recall a catchphrase to the effect of "a PC needs at least 4 Meg of RAM..." (which was a LOT back then) "...to even THINK about multitasking, but a stock Amiga 500 will do it on 512K!"

[@Caseytify]

That's because just about every interrupt driven multitasker used the 386's x86 mode, which allowed multiple virtual 8086 systems to run concurrently. ... Aaaaand where's Amiga today? 😉

[@helldog3105]

I remember seeing this on Computer Chronicles way back in the day. It was interesting then and it's interesting now. Also, I hope you find a 386.

[@Operation8Bit]

Glad you enjoyed it, and yeah we're hoping to find one as well. It would be great to do the follow up where we connect it to a terminal

[@SDWNJ]

There was also an OS called PC-MOS, which I just found out is now open source.

[@Operation8Bit]

Interesting that went Open Source. Do have a link you can share?

[@TheSulross]

There were other DOS switchers that made use of the 80386 virtualization mode of the 8086. I used one of those, can't recall the name - VM386 - or some such. I think some of these alternatives were more successful in the marketplace than DR's Concurrent DOS

[@Operation8Bit]

There was that one and a few others like that one and DESQview that @Noel's Retro Lab mentioned in an earlier comment. Byte magazine did an article on a few of them that were available at the time and DESQview was their top pick

[@wizardsghost876]

I really wonder: what would the command 'CPM' do? I had a Siemens PC back then, which came with DOS and CCP/M. How thrilled i was when i tried SUSE Linux the first time, that was sooo advanced.

[@ccanaves]

"4 gigs of memory" :D

[@stevesmusic1862]

Do a video on QEMM!! I used to use it to BBS on my 386. Able to open a dos session when needed

[@theParticleGod]

Do you mean Desqview? QEMM is a memory manager

[@theParticleGod]

Do you mean Desqview? QEM

[@zeke7237]

I wrote large applications with CCDOS running on Compupro 486 S100 boxes

[@Operation8Bit]

Cool. What was it used for?

[@zeke7237]

@@Operation8Bit One was a custom job for a large wholesale nursery, 4 users on Wyse 50 terminals and LA120 Decwriter printers, using a custom application written in Dataflex. Another was for REQUEST TV, one of the earliest pay-per-view movie outfits.,all written in C. Customers dialed an 800 number to buy a movie, I handled ANI data from telco, figured out which headend the subscriber belonged to, and sent a message over the VideoCipher data stream to that headend, which then authorized the customer box.

[@helidrones]

Novell DOS 7 could also handle multiple DOS sessions, unfortunately it lacked network performance.

[@Operation8Bit]

Which is weird considering... Novell? Add to that, Novell bought out Concurrent for MultiUser DOS... Oversimplifying, please don't beat me up in comments :-)

[@bitwize]

SCO Xenix had a program called VP/ix, that allowed you to run DOS sessions on Unix. Later versions also supported a similar program called Merge.

[@Operation8Bit]

I never heard of that before this. I need to go check that out. Thanks for the info 😃

[@bitwize]

@@Operation8Bit No problem! I'd like to see a video about what you can find. Even though it's no longer DOScember... Maybe for JanUnixary?

[@NamesGolden]

you should put the link to the other video in the description. I found it, but make it easier for everyone else.

[@DosGamerMan]

For businesses that would have really helped with productivity pre windows

[@LiamProven]

Not really! Its main use was as a cheaper alternative to a small network, for running accounts software and things, where 1 PC could serve 4 or more terminals, all with people working on the same app -- updating sales figures and so on. It was too expensive to be a standalone single-user OS. In the late 1980s, half a dozen PCs and a network would cost at least £30,000 or so. One £5000 PC and a few £500 dumb terminals could do the same job with CDOS, and save half the budget.

[@lawrencedoliveiro9104]

1:28 Maybe a different Kato -- how about Clouseau’s Kato? Instructed to attack his boss without warning at any time, just to keep him on his toes ...

[@Operation8Bit]

OMFG, I totally forgot about that! Yeah, if you saw us together off camera it's probably closer to that!

[@NomadicDmitry]

I've also never heard of it before. But the question is... Is it true multi-tasking or it's the same thing as Windows 3.x with cooperative multi-tasking?

[@ncot_tech]

So could software be written to take advantage of being run under Concurrent DOS, or is it really just DOS with more steps?

[@Operation8Bit]

The DOS with more steps was just another of my very bad jokes :-) Yes there was an API that developers could tap into that would allow them to take advantage of the multiuser feature. I did some PoC work with this for a medical billing system that I was porting from the IBM System 36, but I never got it to work exactly the way I wanted, so I wound up going with SCO XENIX. The Wikipedia article on CDOS has some more information (en.wikipedia.org/wiki/Multiuser_DOS#Application_software). Also one of the other viewers that commented (Liam) seems to have a lot more actual "hands on". He may be better able to shed light on the API.

[@lawrencedoliveiro9104]

10:21 Doesn’t “more

[@hofinger82]

"What dos that mean? I can wear my shirt with the little Santas on it" --> Subcribed :D

[@Operation8Bit]

LOL... That's my Christmas Hawaiian shirt, it has Santa hanging out on the beach. Thanks for subscribing!

[@LiamProven]

A fun video and good to hear about an OS I used and supported back in the '80s. I feel the terrible need to point out a few small mistakes, though... 4:17 - "First released as 'Concurrent PC-DOS" - no, it wasn't. What became Concurrent DOS was originally CP/M-86, and then Concurrent CP/M, or CCP/M for short. 5.25 - "Eighty-thirty six"? I've never heard it pronounced that way, but even so, nuh-uh. It's an 80386 not 8036. In the UK we said eight oh three eight six, but however you say it, you missed a digit. :-) 7:54 - WinWorldPC? You know Microsoft makes Word 5.5 for DOS a legal free download, right? If you don't want legit, well, Word 6 is much better. You didn't mention the bit that's most interesting. CDOS lived on for many years afterwards. When DR stopped selling it, it sold rights to 3 VARs who continued selling it -- IMS Real32 stayed on the market the longest, I think. But the 286 version, which had problems with the first 80286 chip released because Intel dropped a feature it depended on for DOS compatibility, went its own way. It became DR's real-time OS, FlexOS, complete with a multitasking GUI derived from GEM called X/GEM. You never event mentioned that millions of Atari ST owners ran a DR OS, TOS with GEM. FlexOS became IBM 4980 OS and is still sold today by Toshiba for point-of-sales terminals.

[@Operation8Bit]

Hi Liam, thank you for taking the time to leave your comments. The one part about the mispronunciation was just me totally flubbing the line (I do that a lot, but we normally catch it in post). The way I planned to pronounce it was “eighty, three eighty-six”. TBH, I usually just say “three eighty-six” Aside from that, thank you for providing the additional context on the points I skipped. It’s also nice to know that I’m not the only one that worked with this OS, although based on your other comment it sounds like you did way more with it than I did.

[@LiamProven]

It happens to us all. I must confess some vested interest - I am trying to revive interest in DR-DOS myself. I have some downloads and must work on a VM image. Maybe in time for DOScember! liam-on-linux.livejournal.com/58013.html

[@almostliterally593]

I knew about concurrent DOS because i watched the computer chronicles with gary kildall

[@Operation8Bit]

I love that all those old episodes are still available on YT, including the CDOS one

[@Aethelwolf]

I had a copy of it at one time

[@pvc988]

There is SepTandy (September), DOScember (December). Maybe there should be JUnix (June) too.

[@Operation8Bit]

That's pretty clever! I'll pass it along

[@thedogwooddandy]

Bro if this is just you getting tipsy and talking retro tech you can call me a subscriber. I see you may be a new channel somewhat and if I may offer any advice whatsoever to really amp up the professionalism (which you really get a lot right already) is to do more jump cuts during your monologues. For instance, your joke would've been far more "cute" regarding the "sarcastic sidekick", if you had less lingering time between the joke and our realization of it. Pacing is key to comedy. But in general, it's near KZbin practice to jump cut the heck out of a monologue because alot of people aren't professional actors who can reel off words without "ums", "uhs," and unnatural space between phrases. All that aside, love it man! I'm on board.

[@Operation8Bit]

Hey Joshua, Welcome aboard! If you’re into drunk computer history, then you definitely found the right channel! 🍹 Thanks for the feedback on the timing and editing. This has been something that I've been working on since we started. If you go back to some of my earlier videos, you can really see the difference between those and some of my newer ones. Still room for improvement and constructive feedback is always welcome. --T

[@thedogwooddandy]

@@Operation8Bit no problem, hope it came off as nice as i think you've got a good thing going here. i didnt really review the older videos. but i can certainly see the quality you've sought to bring to your channel. in all its great!

[@Operation8Bit]

@@thedogwooddandy Yes it did, and again thank you for the constructive feedback. I'm sure that there are more than a few others that may share the same thoughts. The only we get better is to get good honest feedback. Great example are some of the comments we got on audio. Not only did we work to fix it, we even picked on ourselves in this episode about it :-) kzbin.info/www/bejne/iWS0po2og9KCgac And yeah, that is a very loud shirt ;-)

[@gazzmanp]

You have an Atari 600xl behind you. Of course I'll subscribe!

[@Operation8Bit]

Thanks for subscribing, glad to have you here! Yup, my little 600XL is in a place of honor right there beside it's big brother the 800XL, and not that far from it's cousins the 130 XE and an XEGS. That little 600 is special, I am the second owner and I promised the person I bought it from that I would give it a good home. You know, I really need to do more videos on the Atari computers. :-)

[@AlsGeekLab]

Great video. Look forward to the... Sausage making.... 😂

[@Operation8Bit]

Thanks Al, but you may not be as happy after you see all the behind the scenes meat grinding 😂

[@henrikgustav2294]

Can i use dumb terminal with concurrent dos?

[@Operation8Bit]

Back in the day one of the things I used CDos for was for a medical billing system I wrote. We connected 4 Wyse terminals over a serial connections to the PC running the software. It worked, but I remember that there were a lot of setup issues. On the topic of setup issues, if you haven't you may want to check out the companion Nibbles & Bytes video that covers some of the problems we had. Also there is a partner video by our friend Retro Tech Chris where he connects a remoted dumb terminal to our CDos Server. Link to the companion episode: kzbin.info/www/bejne/qJCYqYSZqKt-jJY

[@atlasfugged9044]

im guessing the games wouldnt run on concurrent dos because your VM wasnt set up right or that hypervisor doesnt feature what those games need to run

[@qubex]

Four gigs of RAM?! 🤯

[@ronslayton5270]

SUST (Single User Single Task) - DOS, CP/M SUMT (Single User Multi Task) - Windows 1 - 3.1, BeOS, Haiku MUST (Multi User Single Task) - ??? MUMT (Multi User Multi Task) - Every modern OS Anyone know any MUST (Multi User Single Task) OSes?

[@alexsmirnof]

I used it.

[@kimchee94112]

DOS was unstable, it crashes even when not multitasking. Frustrating when it crash towards the end of a 2 hour long CAD plot, then need to plot the 2 hour drawing all over again. You don't multitask, you don't even touch the computer and hope it finish the task. Those were the days. CP/M-86 was more stable at the time but it didn't have the various programs for DOS.

[@robsprokholt8831]

Is it realy a multitasking os? You showed programs switching. I hope to see a next video running concurrent on real hardware in stead of an emulator

[@Operation8Bit]

Actually it is. I worked with this OS IRL back in the 90's, and despite the shortcomings, the marketing pretty much met with the reality. Unfortunately we couldn't get it t run on modern hardware for this demo, If we can get our hands on a proper 386 we would love to show what it is capable of .

[@LiamProven]

Yes, it really multitasks. And the terminals can have 4 sessions, too. PCs natively support 4 serial ports, so 4 apps on the host plus 4 apps per terminal -- in theory, 20 concurrent programs, each with up to 640kB of RAM. If you could afford that much memory! What CDOS never did was windowing, so you can't see more than one app at once. How I personally used it in the office: I installed it on demo machines, set them rendering a big fractal that would take hours in the background, then switch consoles and load MS-DOS' COMMAND.COM so it looked like a vanilla DOS PC. You could run apps and work on it and never know that it was working flat out in the background. 386s didn't need heatsinks and had no cooling fans, so you could not hear that the PC was working much harder than normal...

[@dmitryhetman1509]

I am new subscriber

[@Operation8Bit]

Welcome! Thanks for subbing!!

[@chriswatson2407]

Great video. Better without the irritating 'on hold' muzak all the way through.

[@zzco]

The "Intel 8036" processor? I think you're missing an "8" there? the Intel 80386? Buehler? ...Buehler? ...Buehler? :p

[@Operation8Bit]

LOL, yeah I flubbed that line pretty bad :-)

[@zzco]

@@Operation8Bit No worries! recommended from DOScember. I have a couple, actually one I may be interested in getting rid of. you have a discord or anything? :p

[@Operation8Bit]

No discord, but you can reach me at [e-mail] (I know, email... so early 2000's)

[@zzco]

@@Operation8Bit I have a vanity domain as well, so. :p

[@lawrencedoliveiro9104]

11:18 Bulwer-Lytton was not American.

[@Operation8Bit]

True... but Snoopy is 😄

[@duderobi]

Digital - makes CP/M Tim Paterson - sells crappy copy running on x86 to Microsoft Digital - makes cp/m dos-compatible

[@Operation8Bit]

Pretty much sums it up

[@lordterra1377]

Didn't CPM do all of this much earlier than DOS? At it's core Msdos is just a very crude copy of CPM.

[@Caseytify]

Um, no.

[@anno5936]

What is DOS ? Democratic Organisation Sesamestreet ?