The NEC APC runs MS-DOS from 8" disks

The year was 1982 and NEC entered the home computer market (outside Japan) with the NEC APC, or Advanced Personal Computer. The machine sported an Intel 8086 CPU, ran MS-DOS and sported dual integrated 8" floppy drives! In this video I'll take a look at the machine inside and out, and do a repair on it so I can get it working again.
Part 1: This part!
Part 2: • Using the NEC APC, Jap...
-- Video Links
NEC APC (Wikipedia)
en.wikipedia.org/wiki/APC_series
NEC APC Manuals (Bitsavers)
www.bitsavers.org/pdf/nec/APC/
NEC APC Software (Bitsavers)
www.bitsavers.org/bits/NEC/APC/
Adrian's Digital Basement Merch store:
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-- Tools
Deoxit D5:
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O-Ring Pick Set: (I use these to lift chips off boards)
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Elenco Electronics LP-560 Logic Probe:
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Hakko FR301 Desoldering Iron:
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Rigol DS1054Z Four Channel Oscilloscope:
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Head Worn Magnifying Goggles / Dual Lens Flip-In Head Magnifier:
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TL866II Plus Chip Tester and EPROM programmer: (The MiniPro)
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TS100 Soldering Iron:
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EEVBlog 121GW Multimeter:
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DSLogic Basic Logic Analyzer:
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Magnetic Screw Holder:
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Universal ZIP sockets: (clones, used on my ZIF-64 test machine)
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RetroTink 2X Upconverter: (to hook up something like a C64 to HDMI)
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Plato (Clone) Side Cutters: (order five)
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Heat Sinks:
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Little squeezy bottles: (available elsewhere too)
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--- Links
My GitHub repository:
github.com/misterblack1?tab=r...
Commodore Computer Club / Vancouver, WA - Portland, OR - PDX Commodore Users Group
www.commodorecomputerclub.com/
--- Instructional videos
My video on damage-free chip removal:
• How to remove chips wi...
--- Music
Intro music and other tracks by:
Nathan Divino
@itsnathandivino

[@adriansdigitalbasement]

I added some links to the description of a source for diak images (of some software) and scans of the manuals for this machine.

[@kensmith5694]

8255 = 3 each 8 bit parallel ports. Likely the printer uses part of this guy 8237 = DMA controller and also dynamic memory refresh. 8254 or 8253 = 3 16 bit counters that do the 18Hz interrupt and also times the memory refresh 8259 = interrupt controller 2 of them used in PCAT also. later on NEC made their own versions of each of those under a different part number

[@kensmith5694]

look to see if the DOS has interlnk and intersrv. If so they can be used to transfer files. You need another DOS with interlnk and intersrv

[@grantfryer1]

Awsome, what is my special gift you are promising? Just kidding I reported the post as spam.

[@gelo1238]

Some scamer in comments...

[@gelo1238]

@@grantfryer1 Oh you get this scam message too xD

[@clifffiftytwo]

Really brings back memories of helping a friend back in the day. He was comptroller at a small business and without any discussion, the owner bought a “computer for accounting” - this model or very similar. My friend hadn’t a clue but was expected to set up a database to monitor inventory- the situation so hopeless as to be hilarious. I was his friend and an engineer so of course I understood computers, right? I remember the 8”’disc drives but not what o/s it ran - we learned dBase2 together and set up that database. He’d buy me dinner (my only compensation LOL) and we’d put in a few hours typing away. The computer worked great - not a bit of trouble.

[@lasskinn474]

Sounds like it worked out great for the small busines owner lol

[@Clavichordist]

Same for me as well including dinner or lunch. These were great times in the computer industry, I think.

[@NaoPb]

Lovely story. Thank you for sharing this with us Cliff.

[@tedmoss]

OS's were many, such as CPM, Control Program Microcomputer, written by a naval postgraduate student for his thesis, Gary Kildall (putting it in the public domain). Subsequently ported by Bill Gates and a friend into the Microsoft Operating System and PC-DOS. They just changed a few names of the programs ported by them into the Microsoft Operating System and PC-DOS. The reason was nobody wanted 200 different operating systems. But Gary made a lot of money even though Big Blue screwed him.

[@clifffiftytwo]

@@tedmoss As I navigated it, it must have been msdos or cpm. Might have moved around a file or two but mostly we worked inside dbase.

[@GreenAppelPie]

It’s absolutely fantastic to see such in-depth documentation that came with the machine. I wish companies were required to do so after the product line was discontinued.

[@stevethepocket]

They should be required to do it as soon as the product is released; if they get to wait until after, the company might already be on the verge of going out of business so there's nothing you could do to punish them for noncompliance.

[@horusfalcon]

@@stevethepocket I'm with you on this one: manuals, schematics, etc. should be provided with the system at sale, at least as a separate purchase option. That way, those interested can buy them, and those who aren't can opt out.

[@nitehawk86]

@@horusfalcon PDFs dont cost money to copy. It should be part of "right to repair", instead of them charging thousands of dollars for the documentation.

[@TuxraGamer]

@@nitehawk86 They would probably have to pay for some redistribution fees before being able to give out the documentation, but I'd be fine if I had to pay for these as I'm gonna take a big cut off that as well (as I'd use them for any future repairs).

[@breakbumper]

Indeed. It sounds like NEC wanted this computer to be a standard implemented by everyone.

[@7MPhonemicEnglish]

It's always interesting to discover all the systems that were better but didn't get drawn into the mainstream.

[@alancotterill2750]

Also, if ever you wish to access the PSU just remove the two screws below the screen bezel - lift the APC up from the lower edge of the bezel and you will see the screws securing the PSU - which just slides out. The APC is really nicely built. NEC really went to town with it!

[@nebular-nerd]

Those PCBs are works of art, they really went to town with the connectors and chip sockets, even the solder work looks amazing. 🤓

[@paulmichaelfreedman8334]

Looking at the industrial style build of this machine, it would have not been afforable for many people at home. This looks like it's a computer meant for industrial use, like in a plant control room.

[@vibrolax]

Snagged one of these (on loan) from my employer around 1983, and spent countless hours disassembling the BIOS and IO.SYS. I also programmed the graphics board. I loved the crisp monochrome display, designed for kanji and katakana. Man those drives were noisy. Oh yeah, the internal construction quality was first class.

[@edmclaughlin4923]

These were in the computer labs at college my freshman year. We ran CPM OS disks and programmed in Basic. What a way back moment!

[@NaoPb]

Nice picture of your setup on your channel Ed!

[@erebostd]

Cool thing, thanks for sharing 😄👍

[@snakefriesia6808]

my early computing days were at school too, with an Exidiy Sorceror machine which also ran CPM and we could only programme character-based stuff on there .. no graphics capabilities at all..

[@InssiAjaton]

A few memories. Thee company where I used to work got at first a TRS-80 for inventory control. It came with a tape drive and 16k memory. Both turned out to be inadequate, so a memory expansion to 48k RAM was bought and I got the task to install it. Soon after, two floppy drives were also added. By default it booted into BASIC. It was used for the original purpose for a number of years. Next, the accounting wanted their own computer, and as then the common "opinion" was that IBM PC was the one that businesses were supposed to prefer (and that "no business would make a wrong decision by getting an IBM"), so the search was started on that basis. However, a "Clone" marketed as Sperry won, especially by price. Actually it was made by Mitsubishi. Anyway, it came with MS-DOS version 1.5 and was buggy. But rather quickly we got version 2.1and that worked fine. It still was equipped with two floppy drives. But once the 2 accountants had settled on computerized operations, then they procured an XT with 21 MB hard disk. Then the Engineering secretary gor another XT for her report and letter needs. Its specialty was that it was equipped with an interface to print on an IBM typewriter. Finally, a few years later, Engineering got their own computer that by then was an '386 and we got our first CAD program and a large format plotter. After sharing the Engineering computer, I built my own computer from a kit, running enhanced CP/M by Richard Conn on it.. Even later, I bought my first laptop computer, made by NEC. It has 2 floppy drives and a specialty, a RAM Disk. I still have it, although its NiCad battery of course is dead. I am in the process of replacing the 8 cells with 3 LiFeO4 cells. There is some story about the AMD 9511 to Intel license deal. AMD got as part of the deal right for the Intel 8088, but then Intel went their own way with the 80287 and did not extend any more licenses to AMD. That was the beginning of the multi year court battlle between the two companies. I followed that, because we used the AMD 9511 math processor in one of our products.

[@snakefriesia6808]

@@InssiAjaton ah, memories, something similar happened at my company , only with amstrad/schneider pc's

[@cracyc00]

The PC-9800 also had high res text modes (it also had the bitmap modes built in) needed for Japanese text which is why PC clones didn't do well in Japan until Windows 95 arrived (DOS-V also helped earlier but W95 broke the PC98).

[@tahrey]

And this is sort of a proto PC98 in a way (with the APC-III literally being a rebadged one), it has the same video controller etc...

[@alancotterill2750]

I made images of my APC disks using a FDADAP adapter, an old Pentium PC with DOS 6.22, Dave Dunfield's ImageDisk and one of the APCs drives. It took me ages to discover that you have to change a jumper on the drive's logic board before it would work.

[@techkev140]

That disk drive sounded like my first experience with an Amiga 500 3.5" floppy drive. That rough grating sound with drawn out tones and clicking as the drive heads move to a new position. The reassuring sound of data on its way...

[@Pistoletjes]

What an awesome machine. The clunky sounds just add to the experience!

[@stephenwalters9891]

When I worked for a Commodore dealer, in the 1980's, we had a visit from an NEC representitive offering us a dealership. We went for the ACT Sirius-1/Victor9000 instead.

[@gendolookin]

I always start your videos thinking to myself "I'll check it out for a few minutes and see what this machine is about". Then 49 minutes later...Wow it's over already!!!?!?!?!?

[@spagamoto]

Always nice when the documentation is respectful of users! Publishing the PAL equations - wow, really top notch stuff. I wonder where the engineers who designed this thing are now. Perhaps they've brought some of that philosophy to their later works.

[@tahrey]

I can't remember which, but either Tandy or Olivetti/AT&T did similar with their machines of a similar ilk (as in, fast-ish 8086 based with 400 line displays and somewhat oddball bus connectors etc). Problem is there were some glaring mistakes made with some of the published data, which I've run into when trying to do the screen refresh calculations on that side... (it "scrambles" the input to the CRTC through a PAL such that directly programmed CGA modes, including some custom ones, will work correctly with line-doubled output and it isn't limited to well behaved pure-BIOS software compatibility ... e.g. it solves the "MS Flight Sim" issue. Problem is, it does that with all the native hi-rez modes as well, with anti-scrambled data sent to the PALs from its own BIOS... but if you follow through the process, the numbers that come out the other side are... fairly believable, but are at odds with what the manual otherwise claims the output frequencies / etc should be. And there's no way, without scoping the real hardware, to tell if it's those precalculated figures, the PAL equations, or the anti-scrambled BIOS data that's incorrect... but plenty of opportunity to smoke a fixed frequency monitor with bad code, or a bad translation of good code if you've had to spin up a replacement PAL for a burned out one using the published equations...)

[@jasper-byrne]

this was my dad’s first computer and he wrote scripts for his bbc tv shows on it, forever reprinting them on the incredibly loud daisywheel!

[@andygozzo72]

was he Johnny Byrne?

[@jessihawkins9116]

@@andygozzo72 no

[@andygozzo72]

@@jessihawkins9116 there certainly was a johnny byrne that wrote 2 stories for doctor who, script editor for all creatures, plus writer for space 1999

[@jessihawkins9116]

@@andygozzo72 yeah but it wasn’t him

[@jasper-byrne]

@@andygozzo72 he was indeed

[@tonycosta3302]

I really miss old computers. The size, mechanisms, and complexity imbue them with a sense of power and mystery. Todays machines seem mundane by comparison.

[@jessihawkins9116]

yeah but those older machines can’t run windows 10

[@russellhltn1396]

Cool! My first job out of college sold these things. Really brought back memories (like how noisy the drives are and how C/PM 86 seemed to be really disk intensive. As well as repairing the very first hard drive. (The cable came off inside the hard drive enclosure.) It was my first experience repairing something completely out of my league. You can see the high persistence in the way the cursor blinks. The color system was really impressive, especially when running a CAD demo display.

[@tedmoss]

I fixed hundreds. Not an exaggeration.

[@alancotterill2750]

Adrian - that 'bump stop' to rear of the keyboard hides a small switch. It's a reset switch when you are in MS DOS / CP/M but if you press it before booting from a disk ( whilst the POST asterisk is on the screen ) you will get in to a HEX monitor environment.

[@rommix0]

So kinda like the programmer's interrupt key on the Macintosh.

[@alancotterill2750]

@@rommix0 Yes - that's about how one of the developers at work described it to me. My APC is at work these days - keeps my wife happier!

[@jessihawkins9116]

I was just about to say that 😩

[@95Comics]

I love when you say “without further ado, lets get right to it” right before hitting a musical start montage 😂. You are the best adrian! This is one of my favorite channels!

[@MagicalAscension]

I worked in a public building in 86 or 87 during their process of converting their HVAC installation over to control by a system that used one of these as the operator's terminal. It had the color monitor and did some really impressive graphics for that time. I learned CPM 86 backwards and forwards..

[@leetaeryeo5269]

My god, the aesthetics of this machine are so up my alley. I kinda hate I missed this era of computing

[@glendady8879]

Maybe Usagi Electric could make a 50pin adapter between your drives and the standard Shuggart connector. He has done something like that already for his Centurion Project.

[@russellhltn1396]

With everything documented, that's a very good possibility.

[@johndododoe1411]

PC floppy interface is based on a connection with 4 select lines like this interface, but IBM abused that to construct the twisted part of their two-drive floppy cable.

[@tahrey]

Now that's one cross connection I wasn't expecting to see, but getting him and Adrian together could have interesting results.

[@tahrey]

@@johndododoe1411 Even with that issue it should be possible to knock something together. They're just 1-of-many chip selects in essence. Even if you have to twist or untwist wires in the cable. Maybe even come up with some kind of cascading passthru kind of thing like the Atari ST floppy connection takes advantage of to select from two drives that each only have one drive select input available, but two outputs on the computer... Or use a simple multiplexer / decoder IC... etc.

[@johndododoe1411]

@@tahrey Point is that I suspect it's really the same interface.

[@Merovign]

Awesome. The APC Color is one of my top-tier "Unicorn" machines, I have mulled over the idea of re-creating it with 3D printed parts (the case, obviously)... I doubt anyone else would do it but having everything so heavily documented would make it easier to emulate - and the emulated version could more easily max out RAM, graphics, speed, etc. I'd prefer to have the real thing, obviously, but who knows if I will ever be in the right place at the right time!

[@jadall77]

Having one of these running on full ram man you could do a lot with it. especially if you get 128 off that battery memory rom stuff.

[@F4LDT-Alain]

Very interesting machine. Several 8086-based computers came out before the IBM PC or at the same time, running CP/M 86, its multi-tasking variant Concurrent CP/M 86 and later MS-DOS. Most were based on completely different architectures. Some were way more advanced than the IBM PC with hi-res monochrome graphics, DMA for floppy disk and hard drives, supporting much more RAM etc. I worked on a machine somewhat similar to that NEC box. It was available with a choice of 5"1/4 or 8" drives. I remember that the 8" drives were incredibly faster.

[@idahofur]

I would like to add to that. On several machines you got more ram and other options than in a IBM PC computer. Plus if somebody had not mentioned it yet. You would just call those machines MS-Dos compatible. Thus, any True ms-dos program should run. But as pointed out. Not IBM-Compatible programs.

[@jessihawkins9116]

I don’t see how much faster they could be. My 486 has a 1.2mb 5.25” drive that’s pretty fast 🤨

[@tschak909]

The APC, was the international version of the NEC N5200 PC. They are sort of cousins to the PC-9801 series machines. NEC also put their uPD7220 high performance graphics chip on there, which has all sorts of goodies on it (such as accelerated line draw and complex pattern fills). It works extremely well with GSX under CP/M-86, and the earliest versions of AutoCAD had direct support for it, which made it one of the best AutoCAD machines for a couple of years.

[@DarrenHughes-Hybrid]

When you're done playing with it, you should donate this computer to a museum. I have not seen one of these before and it seems like a mile stone computer and it's in a decent and pure state.

[@mattmattelig]

great video!! nice to see that there were some companies that built really good products that just work even after all these years, and documented them so well. I saw an ad for this machine many years ago and I really wanted one but where I was living at the time, there were no dealers that sold this. Oh how I wished I would have found a way to get one, especially after seeing this video of yours. Thank you!!

[@PaulinesPastimes]

Wow, what a fascinating video. Talk about memories. I worked for a company in the early 80s that had two of these for a short time before they decided to go with fully IBM compatibles. A friend worked with them and it all seemed like magic to me. He gave me some grey plastic Verbatim 8" disk boxes which I use to this day to store 7" 45 rpm vinyl. I was downstairs being the glamorous receptionist, belting out letters on an IBM Selectric 2, the one with the correction tape, which I used a lot! Ah, the 80s, good times!

[@twocvbloke]

Interesting watching the power switch just light up on its' own at 42:52, must have a loose connection to the neon lamp inside the switch or something, but that aside, it's neat seeing this machine come to life, especially the 8" disk drive just working like it never sat for however many years it was on a shelf somewhere, pretty cool stuff... :D

[@kaitlyn__L]

I wonder if it took a little time for the neon to vaporise after sitting for so long

[@1kreature]

@@kaitlyn__L Neon is a gas it does not vaporize, but it may have taken a while to strike...

[@kaitlyn__L]

@@1kreature tbqh I’m mostly just familiar with sodium lamps, so it was just a shot in the dark about how gas discharge lamps can take a while to get going after a long time

[@lasermike2147]

As neon lamps age, they lose the ability to strike or begin glowing in low light conditions. You can help an old lamp strike with an external light source. I wonder if that's what happened here.

[@tahrey]

Seeing as the switch was in the random spares bin, it might itself have been swapped out for having an unreliable indicator light in it...

[@parrottm76262]

Those early NEC computers were fascinating. Gaming on the NEC's in Japan early on was an experience. Great dive into this computer family.

[@JimboPalmer]

I attended Western Washington University from 1982 to 1986 as a CS major. Our computers were always overbooked so I learned all the odd computers on campus. Engineering has a NEC APC as a CAD/CNC device. Ours was color and I wrote some CNC designs, but mostly used WordStar on a computer with no other students wanting it.

[@Nebula1701]

I love that sharpies are everyone's favorite touch up paint.

[@schmeat2717]

Wow NEC has always been on the cutting edge. Impressive

[@vwestlife]

If it's like the PC-8001A, then the drive motor stays running for about 2½ minutes after the last disk access and then shuts off. NEC's 5¼-inch drives had a single LED that glowed dimly when the drive motor was running and full brightness when it was being accessed.

[@ObiWanBillKenobi]

Thee Sanyo MBC-775 from 1984 also had those mechanisms for its 5.25-inch floppy drives. It also just sat there once powered on and did nothing until the floppy drive closed on a proper boot disk. In its case, the only proper boot disk was a proprietary "Sanyo" brand of MS-DOS 2.11 or earlier. It would not boot with any other floppy.

[@SobieRobie]

Very interesting machine. I would say it is much interesting than original IBM PC. And the fact that it works with no problem after all these years just proves quality. And the manual is just fantastic!

[@MaxCarponera]

I love the persistence of the green phosphorus displays

[@burnte]

I love the AUTHENTIC audio break there. Really makes the basement aspect tangible. 😉

[@compu85]

Sark has one of these with the color display. It's *SUPER* sharp, and very high resolution - needed to display Japanese characters properly!

[@Lukeno52]

Now that is a glorious looking vintage machine.

[@Drycleanerguy]

I was software developer back in 1982, and we selected the NEC APC for our software. It initially offered two operating systems, CPM-86 and the UCSD p-System. We used CPM-86, which was a very poorly written operating system. Later, MSDOS became available for the APC. The APC came out at about the same time as the IBM-PC, so no, it was not hardware compatible. The APC was indeed very advanced, especially compared to more primitive designs such as the IBM PC. While you ran into data referring to the CPU as an 8086, the actual chip was an NEC made variation, the NEC V-30 which was 8086 compatible, but faster at the same clock speed. Mine had a single 1Mb 8" floppy and an external 10Mb hard drive. It came with an excellent full keyboard, including separate cursor keys and a numeric keypad. It also featured full EGA level color graphics (640x475), and it contained a separate graphics coprocessor and it had a built in sound card. I didn't personally work much with the video processor, but I have a vague recollection that it drew things on the screen with vectors, and that, for the time, it was very powerful. The machine came with a full listing of the bios and a full hardware diagram. That allowed me to take more control over the hardware, including the interrupt control, which allowed me to replace the printer driver with one that was interrupt driven. (The default driver used a timing loop to wait predetermined times between characters). That enabled me to edit and compile programs at the same time that I was printing. It also allowed me to drive the printer much faster, and it could keep up with a 300 lpm line printer. My recollection of how the sound system worked is that you coded the music as a series of notes, along with note duration and volume, and placed the string data in memory, and then told the sound system to play the data in the string. It was fairly primitive in sound quality, but was far, far more advanced than a simple "beep". All of my information is from personal memory, so information you found online may be more accurate....

[@stannovacki2406]

Another great retro-computer story. Thanks for another walk down memory lane Adrian! At the time of its introduction, even MS expected that the IBM platform would be one of many x86-based platforms, in much the same way the Z80 dominated the CP/M market. Consequently, they cleverly arranged to market MS-DOS as a "generic" equivalient to IBM's PC-DOS, thinking that DOS-compatibility would pave the way to 16-bit success. Computers like the Tandy 2000, the Heath/Zenith H/Z-100 series, this NEC machine and others reflect similar thinking. Personally, I think the diversity of the CP/M ecosystem was one of its strengths rather than a weakness, and that the "need" for 100% IBM hardware compatibility, rather than a more-flexible software compatibility, stifled a lot of creativity and "individuality" in the 16-bit computer market, resulting in the rather bland choices we have today. PS: Sharpie case repairs rule! :-)

[@Clavichordist]

This was an interesting time. I worked for an early computer manufacturer that made video terminals and early PCs. They had CP/M and IBM compatible systems available. When IBM came out with the XT computer, this nearly put this company out of business along with so many other companies that relied on the IBM original design as well as the non-compatible designs nearly overnight. It's as if IBM flattened the playing field not only with the expanded bus, but also with the standardization of the platform. The full adoption of PC-DOS and later MS-DOS fully nailed the coffin not only for the hardware but also for CP/M. It showed how much power IBM had over the computer industry back in those days.

[@dustinhipskind7665]

It is interesting to see these again. We were still using these in my High School in 1996.

[@TheEmbeddedHobbyist]

Nice to see old kit up and running. We used pdp11and pets before moving over to pc's. We also made our own 8080 board to control our first digital audio system, was a greater time to work in R&D. :-)

[@michaelhaardt5988]

I would not have thought to ever see one of these again. Thanks for that surprise!

[@benanderson89]

That disk drive sounds amazing. There's just something about such a pronounced "the computer is thinking" sound.

[@alancotterill2750]

One of the things I love about PCs from this era - you can almost see / hear what's going on inside all that silicon.

[@kaitlyn__L]

I’ve still got such a strong nostalgia for the sounds my first computer’s hard drive made. Both the large seeks and smaller clicking sounds. If I ever rescue that beast it still won’t be the same, if the drive is silent.

[@midimoog]

Look at how many chips there are on the FDD! They must have been quite advanced devices at the time.

[@Toby_the_Glen]

Those floppy disks bring back memories. Back in the '80s I worked in the printing industry typesetting. The amount of times we'd load up jobs and they had corrupted. Even new disks would fail, just a lottery?

[@arthurjennings5202]

The NEC would have been a great process control machine because of the extended interrupt processes. People used Digital Equipment for process control for the same reason.

[@charlesjmouse]

Always very good, thank you. APC - Anachronistic Personal Computer... ...maybe Armoured Personnel Carrier..? PS Good Old NEC: "Where to put the power cable?" "How about the front?" "Err, ok. What about the keyboard connector then?" "Put that on the back of course!!!" "Of course..." ... "Um. should be hide the ports from the user?" "What do you think?" "Uh-ok..." "But be sure to fit an access panel just in case they have monstrously big hands."

[@drgiller]

Ah, the Sharpie touch-up trick. Often, you can go back after it's well dried and rub it a bit with your bare fingers, and some of the remaining purplish tint will go away, making the touch up even more convincing.

[@adriansdigitalbasement]

Oh nice! Down in the basement the lighting is dim, so I really don't notice it, especially compared to the glaring marks it had originally. And the only real difference (in color/tint) is the sharpie is a bit more shiny than the paint.

[@DaveMcAnulty]

@@adriansdigitalbasement Might want to pickup a black acrylic marker. It won't fade/purple like sharpie and worse comes to worse you can remove it with just water!

[@HeavyD6600]

Great video, Adrian! The manual scan was so dirty, I'm certain I scratched my monitor trying to get the artifacts off!

[@DevilishDesign]

Just a heads up, the PSU will actually slide out the front of the case (Think there are a couple of screws under the front edge.)

[@ajslim79]

42:52 how the power-switch magically lights up out of nowhere..

[@clivejones5880]

I have a couple of these APC systems in my shop, both are monochrome/green. The color version has an absolutely gorgeous display.

[@rager1969]

This computer looks familiar to me. When I was a teen, I decided to circle every number on a Byte magazine more information card and got TONS of brochures in the mail (my mailman probably hated our house). I probably got a brochure for this line of computers (I remember a lot of PC compatibles and S100 CP/M machines).

[@BlackHoleForge]

Thanks for taking the time to label it part one. It really sucks when you are deep into a video and then they just cut the video on a cliffhanger with no warning.

[@whitesands928]

Back in 1989 a mate of mine bought a job lot of these and printers, we cleaned them up and sold them on, I kept one, I think it was running Dos 1.1 and cp/m, remember having basic, muiltplan etc. Heavy and built like brick…….. it was my first computer and learnt a lot. Thanks for the review.

[@JustinEdwords]

I learned MS-DOS 2.11 on this when i was like 11 years old! It was pretty useless even then, but it was my useless and it forced me to learn things! It was a liquidation from FedEx i think - I'm from memphis. I wish i still had it! You could still buy disks for it then, just barely (1992) Thanks for taking me back! BASICA!

[@kimchee94112]

I bought mine monochrome 8” dual disk bundled with softwares and a NEC Spinwriter. It was a business package, came with CP/M 86, Benchmark Word processor, dBase ll and MicroPlan Spreadsheet. Way ahead of the IBM PC at the time. I later added a FORTRAN compiler. You could be on that monitor for 8 hours straight and very comfortable on the eyes. There were hard disk option, math processor, color monitor and could run AutoCad. Later came MS DOS for this machine. I dusted it off few months ago from decades in storage and it booted right up and seems to run fine, really high quality. Most of my old PCs are dead, mostly bad motherboard capacitors and CD ROM drives couldn't eject.

[@angrydove4067]

I always get a kick out of 8" floppies, I have never worked with them. Great to see that machine still has life.

[@williamwallace9826]

Very interesting to see old hardware like that is still potentially functional. In the early 1980s I worked for a firm that had two computers in the front office that ran off 8-inch floppies. Somewhere around 1984 of 1985 (I think) they equipped all of us project managers with IBM PCs. The ones we had were "upgraded" -- they had 384k of RAM, and TWO 5-1/4" floppy drives. (And the standard monochrome monitor). The operating system was IBM-DOS 2.10. We ran IBM DisplayWrite as our word processing software, and the program required shuffling among four different floppy disks, depending on what operations you were performing. We ran the computer and the software from the first floppy drive, and we used the second drive for data storage. After about a year of that, I talked the office manager into letting me buy an internal card that had a 10MB hard drive built into it. That made life a lot easier.

[@NaoPb]

Cool system. I'm looking forward to part 2. It looks like she wants to live. Even the power light started working.

[@nickblackburn1903]

I love the look of this computer Adrian, well done on finding it! Hope to see some adventure games or similar on this system, seems appropriate?

[@joe08867]

I love the look of real 80s computers. Thanks for the in depth review of the machine. Look forward to seeing more of it.

[@fotografm]

Geat video ! I think we had one of those in the lab running Basic back in the 80's !

[@fixitalex]

That's really great to have all the schematics. Despite everything is in working condition. And that's also great!

[@johndododoe1411]

IBM PC came with complete schematics and listings too, that's why it was so quickly cloned, teaching everyone to stop doing that.

[@fixitalex]

@@johndododoe1411 Had consumer versions being sold like this? I remember soviet clone of IBM PC ЕС1840 - is used to came with three thick albums of schematic.

[@Shand1982]

This was awesome, just awesome. Well done!

[@C-r-e-a-m_B-o-y]

You can use Kermit or Move-It or Crosstalk XVI to transfer software. They were all released for APC. You can also use 22disk as well. I see you have about 20 software disks, please upload them! APC software is not very well archived. There were quite a few games for the APC actually. They were 8 color and ran on CP/M mostly. They also required the expansion graphics card. The bumper on the keyboard covers a reset switch. The unlabeled function keys were programmable in CP/M and didn't necessarily correspond to a template. The power supply comes out without taking out the CRT. It is on its own tray that slides out from the bottom after undoing a couple screws.

[@jessihawkins9116]

or laplink pro

[@jessihawkins9116]

@Mr Guru what’s mame?

[@jessihawkins9116]

@Mr Guru oh your talking about STEAM

[@somefreshbread]

The listing of Patreon supporters in the very beginning with the intro is such a nice touch. It seems like such an obvious choice in retrospect, and yet I've never seen it before.

[@maxxlr8tion578]

Lighted, no. Illuminated, possibly, but no. Lit, oh yeaaaah! Lol, I just found your channel and have been absolutely loving the vintage repair content, thank you so much!

[@ednasdiscomachine6049]

This is really not that related, but I have a Series III Fairlight CMI. What made me think of it is that that the Fairlight also has plug-in cards for related hardware functions. The Fairlight’s cards are in a metal cage which are an absolute sod to get out with those push tabs! Also, the Fairlight famously has 8” floppy disks, although mine is a rack mounted version and would have had them in a separate cage. The Fairlight Series III was available in 1986, so not far off the APC in terms of production. I love watching you bring these odd/old computers back to life. I think for me, like others, there’s a certain joy in watching them boot back up again. Terrific video.

[@edgeeffect]

MS-DOS and later doesn't really carry much interest for me but the moment you said "8 inch drives" my ears pricked up. ;) Wow... it looks SO gorgeous!

[@MajorHavoc214]

I always love a happy ending.

[@TechTimeTraveller]

I got one off a local computer store free bench 20 years ago. Was stripped of its cards. I got those, but didn't get anything onscreen. It sat for years like that, one day I decided to investigate again.. discovered a power connector to the monitor was disconnected. Reached in, didn't even feel myself making contact with the CRT neck.. whoosh. Now I'm just waiting to get over my fear of CRTs to replace that. Sigh. Glad to finally see one working here though!

[@2009numan]

what a very interesting video Adrian

[@brentboswell1294]

Wow, Adrian astounds me with a computer that I never knew existed...my aunt and uncle had another Japanese 8086 MS-DOS machine, an Epson PC (purchased from the electronics department at Dillard's in the USA, when they had such a department). It looked a lot more conventional than this, and had 5.25" floppy drives. I think it also had some semblance of IBM PC compatibility, I remember playing Flight Simulator 2 on it, in CGA glory 😉

[@bobblum5973]

One of the Epson Equity series, perhaps? 🙂

[@ChairmanMeow1]

This one was before my time a little bit. Cool machine.

[@more.power.]

Thanks Adrian this computer brings back memories of how limited the early years of computing was.

[@peteroneill404]

Back in the day when I was doing postgraduate work in EE, the department secretary had one of these machines with a 10MB HDD. At the time my Professor was writing two books and the APC was used almost exclusively for preparing those manuscripts.

[@organiccold]

Great stuff Adrian, funny as soon you plugged in the keyboard the light in the switch come on haha

[@VicTheVicar]

I had one of these when I was a kid. My dad bought it from a Finn that got it from a news paper (?). It had the color display and was upgraded to 768k and had a gigantic 10M external hard drive. The floppy drives are 1.2M and the low density format is something like 252k. We had AutoCAD 8 and Wordstar running on it. The floppies should still be in my parents basement, even if the computer (and harddrive) died almost 25 years ago.

[@alancotterill2750]

Hello - would you be willing to unearth those floppies? It would take some considerable trust on your part - but id love to read them and convert to a .img file and them post them back to you? I'd be able to share the files with other APC owners then. Hard to find is APC software.

[@VicTheVicar]

@@alancotterill2750 Sure thing! But I won't be able to do that until Christmas. I think there also was a compiler there as well. Something oldschool like Lisp or Cobol.

[@mal2ksc]

To have the exact right part in your surplus bin, and to remember that you have it: Nice. The neon bulb doesn't always work? It's exactly like you said, "oh well", because the intermediate, half-failed state is to flicker annoyingly. If it starts to flicker, just remove the neutral lead so the lamp can't even try. All the switches I've seen on power distribution boxes of the era have reached the semi-fail state, I suspect they leak their neon slowly but surely, whether you use them or not. The higher vertical resolution was necessary because the machine was designed for the Japanese market, and more resolution is required to render CJK text legible.

[@grantfryer1]

Hey cool the power light came on! It freaking works!

[@julianbarron5293]

Another awesome video!

[@SonicBoone56]

Imagine if this had become the standard instead of IBM. Would be radically different. This thing was way ahead of the curve. And I wish all electronics came with documentation and service manuals as good as the ones NEC made for this.

[@munyxxi]

You NEED to retrobright this machine, is beautiful!

[@HappyQuailsLC]

Reminds me of the WANG Model 1 Personal Computer from 1981. We had one and it with its printer was MASSIVE and it ran on two 8.5" floppies. I would have been on Prodigy early, early on but it required a hard drive.

[@ToxicwasteProductions]

The power light states working in the video also 😍

[@stevencarlson5422]

Really need to see some applications running on that thing love that clunky drive sounds

[@mapp0v0]

My job in the 80's was getting software to run on NEC APC III. Different bios interrupt numbers. Different graphic memory layout. Software I wrote had to run on both PC's and the APC III. The APC IV was PC compatible.

[@rdcfrdcf]

42:51 Patiently waiting for you to notice the power switch light :)

[@poofygoof]

this may be a duplicate comment, but the equations for the PALs in the documentation is first class!

[@isaacschneider7778]

For the serial port you can use a fossil driver. I used them back in the day for multi port serial for my BBS.

[@nudge7033]

I was lucky enough to be given one of these earlier this year. It has sat on the bench in the shed gathering dust until this video inspired me to turn it on. What do you know, it works, has a color screen and a 10mb hard drive although it is missing the data cable for the HD. Has two extra cards which I have no idea what their purpose is yet but will spend sometime this weekend finding out.

[@tikkasen_urakointi]

The lowest option for memory for IBM PC was 16 kB, not 64 kB. The 16 kB model can only run programs from a cassette, because booting from a MBR requires at least 32 kB of memory.

[@0LoneTech]

MBR wasn't a thing until hard drives, which the original PC didn't support. You had to upgrade the BIOS (swapping out the ROM chips) to essentially turn it into a PC/XT for that. Conversely, they removed the cassette port on later models.

[@tikkasen_urakointi]

@@0LoneTech The original 64 kB model IBM PC can boot from an MBR from a floppy.

[@0LoneTech]

@@tikkasen_urakointi That's a boot sector. The Master Boot Record was so named because the usual boot sector was inside a partition. Which isn't a BIOS feature, but the original BIOS didn't support the extension required to add those large drives that needed partitioning.

[@tikkasen_urakointi]

@@0LoneTech That's not correct. A hard disk does not need to be partitioned. BIOS only reads the first sector from the drive and runs it as an executable code, and that's called the boot sector or master boot record.

[@0LoneTech]

@@tikkasen_urakointi The reason to partition them is a bit obscure. It was because the root directory (and file allocation table) is of fixed size, so unless you had some giant files you made partitions to make the large size usable. Later subdirectories were introduced and multiple partitions fell out of fashion, though they were reused for other workarounds like multiboot and working around BIOS disk size limits (e.g. the 504MiB one). BIOS doesn't care or know about the partitions at all, but the typical boot sector just doesn't fit in the MBR because it also holds the main partition table. The PC has a *long* history of ugly workarounds for arbitrary limitations. The MBR is a boot sector, but the boot sectors on floppies aren't MBRs. The distinction is one sane BIOSes don't care about (some insane ones, like some from Lenovo, do). Floppy boot sectors typically do store some disk format information as well, in the BIOS parameter block. Just as the name doesn't imply, BIOS has no knowledge of them either; DOS uses them to not access outside the disk.

[@JenniferinIllinois]

Clankity clank - love the sound of that floppy drive. Ahhh, the days of it's IBM-compatible but it's not 100% IBM-compatible.

[@parjf]

In a previous episode a viewer sent you one or two 8231 (or AM9511, the AMD original design of that Arithmetic Processing Unit). So you would be able to populate the socket.

[@adriansdigitalbasement]

Oh good to know! I have a spreadsheet with inventory of all those chips so it'll be easy to find.

[@parjf]

@@adriansdigitalbasement One additional note - some 8231/AM9511 run stable at 2MHz, some at 4MHz. I'm traveling right now so don't have access to the documentation, but you can check online the exact model number and find out which it needs.

[@daffyduk77]

Thanks! I bought one of these things NEW for an embarrassingly large amount of money 40 years ago, sold it a few years later, it's a clunkapotamus but endearing in its way

[@rrpiva]

Super cool machine!