Compaq was by far *not* the first IBM PC clone -- but as they say, history is written by the winners. Columbia Data Products introduced their first IBM PC clone in June 1982, five months before Compaq, and just like Compaq they also used a legal "clean room" ROM rather than an illegal copy of IBM's ROM like some other companies did. But Columbia stopped making PC hardware in 1987, while Compaq lasted until 2001 when they were bought out by HP. p.s. Bill Gates never said "640K ought to be enough for anyone", either -- especially since when he supposedly said it in 1981, the first version of the IBM PC's ROM was limited to a maximum of 544K of RAM, not 640K.
Yeah, I wish people would stop propagating the idea that the compaq portable was the first IBM clone. MPC1600 owner here! To be fair Columbia Data Products got taken to court by IBM, and IBM won as Columbia had simply copied IBM's ROMs for use in their product (thus violating copyright). Compaq took notice and did their bios/roms by cleanroom so they would not see the same fate. The reason for clones existing at all is a worthwhile read! The MPC1600 was a superior machine every way around the original PC, and you didn't even have to waste an isa slot on your floppy controller as it was built into the motherboard. The motherboard on this thing is HUUUGE by the way! I should really do a video on this thing at some point.
@@cprossu I think you're thinking of Corona Data Systems (later Cordata), who did illegally copy IBM's ROMs and got sued as a result (as did Eagle Computer). Columbia legally "clean room" reverse-engineered IBM's ROMs to develop their own workalike of it, just like Compaq did.
@@darkally1235 It made a good seat on the train, when the carriage was full. How do I know? I lugged around a similarly sized Philips P2000C to various hospitals and other customers back in the day. (2x Z80 with optional 8088 co-processor card, ran CP/M or MS/Dos). It was way more serviceable than that Compaq ever was. A joy to work on. It was about the same size, and almost as heavy. Kept you fit though. www.computinghistory.org.uk/det/7130/Philips-P2000C/
13:43 Wow! That thing has SOVIET parts in it! That EL74LS74 chip was made in the USSR!!! EL was Soviet export marking of Western-compatible parts. But they are still recognisable because of font and crappy (usually) brown plastic. UPD: Oh, there is also EL7438 on the same board
Back then there was a ban on selling computers and the components to Russia, even the ZX80 was banned in case Russia used them as missile guidance systems !
Yes, I just came to the comment section to find out if anyone else catched it! And also a Romanian 7416 on that board, with the 'Beta' symbol on it. I've seen these USSR export EL74xx chips in Commodore Datasettes and 1541 drives as well! Weird! But I've never seen a Romanian one until now!
@@mrnmrn1 Thank you for the information about the chip with "Beta" logo. I suspect it was from Eastern Europe but newer thought that it was from Romania. I am not sure was this FDD originally installed in this Compaq or it was installed by the owner. Searching Web I found this: www.ebay.com/itm/Siemens-Model-FDD111-5-Floppy-Disk-Drive-PN-S22742-A1115-C001/372854101030 You could see that the floppy drive and PCB is the same but this one has Siemens sticker and all Western IC in it. Perhaps, this FDD was designed by Siemens, WST was one of OEM maker and Siemens allowed them to sell overproduced devices by their own brand - so they bought the cheapest parts they could ever find? Just a theory...
@@JLsoft It was _incredibly obvious_ and he even zoomed in at an IC not far from it which had an obvious bit of debris, the top of the blown tantalum type cap he was just talking about moments before, just below it, so looking at the camera's LCD instead of directly at the PCB may have been why he missed the obvious.
@@winstonsmith478 I'm so confused..what do you mean by 'why he missed the obvious'? Are you talking about Dave? ...Because _Dave_ is the one that focuses on that area, points out the problem, and talks about it in the first place for the first time ever...which is why I replied to a reply that was...pointing out the blown cap, as if they thought Dave didn't see it. Is there some earlier alternate version of this video that you both saw where 22:45 _doesn't_ have Dave talking about that specific blown cap, saying that it lines up with the sparks he saw, etc?
11:35 Waxes lyrical about replacing tantalum caps. Next shot, point directly at blown tant. Then spends the next 10 minutes tearing computer apart looking for it. Classic Dave
Hi my guess is he saw it, but being on the floppy controller ( an accessory card ) the pc should still boot up but not have a working floppy. Sort of like say a 26/486 with a faulty isa sound card - they system will boot and run but not that sound card - unless that cap is now a direct short to ground
I remember when I was planning my purchase of my first PC, I was agonizing over whether to get a 286 or wait until I could afford a 386. A teacher told me that there was no reason why I would ever need the computational power of a 386.
Thing is, if you can afford it, sometimes its nice to have extra power incase you do end up needing it (especially for future proofing). While most people should be fine with 8-16GB for gaming, I do a lot of other things too that end up eating up RAM so thats why for my PC I built it with 64GB of RAM (which is nice because we're already starting to see games that want 16 or 32GB for the recommened specs)
"Pin 19 is the clock on the 8088".. 🤣 is it sad for electronic engineers when can remember pinouts of chips without a dataset. I still remember a lot of the 4xxx cmos and 74xxx told pinouts. So sad 🤣
I once got offered a job because I could answer the guys questions off the top of my head about what various 74xxx chips did. He was amazed, LOL. Standard hobbyist knowledge.
@21:24 I didn't know that DMA controllers were in charge of refreshing DRAM! Ahhh what would've been of the 8088 if it only had a direct-memory-access controller, and not a DRAM controller. hahahaha
Used to work for Walt Russell, employee #7 at Compaq, he designed much of the case and peripherals for that machine. He left Compaq when it became essentially TI all over again...
I think I'd be carefull about committing too much to odyssey. Napster War 2.0 is inevitable. You don't have to look very deeply to find the New Napster, and it's way easier than Kodi Pi.
Going to bet the power supply fault is a shorted electrolytic capacitor that provides the POK signal. Generally the power supply had a RC circuit that gave the POK, and had a simple comparator in there that was connected to the power supply controller power, and then compared the unregulated input to the chip with the reference, So that when the input was below around 8V from the 12v power rail, the comparator would pull the POK low to hold the processor in reset. LM311 with the output connecting direct to the pin and ground, and a pull up to 5V, with a capacitor to provide a turn on delay before the reset was released. Reset switch also just shorted out this capacitor to provide the same thing.
Hi - some machines are funny the 12 and 5v specs are sometimes just done on the feeds of the power supply before the board , while others specifically overvoltage the power supply as they are designed to have a final or stable 12 / 5v on all components on the mother board after the power drains by mother board , video card, floppy card , hard drive Regards George
When that came out I was still in high school, and they had just gotten a whole room full of Apple ][ machines. First room in the school that had barred windows, and a door with a second security gate, plus there was always a teacher in there when it was open.
According to the show "Triumph of the Nerds" CPM could have been the OS of choice. But the owners of Digital Research (not sure of name) turned down IBM's confidentiality agreement. So IBM turned to the programing languages supplier, Microsoft.
I hired on as Service Manager in 1979 to Store #85 of Computerland, which was a chain of retail stores all over the U.S. - this one was in Sacramento CA. I worked for the local franchise which grew to 5 stores in northern California till 1987. I went to many service training seminars over the years including at IBM for the original PC. That one was held at one of their labs and was a week-long, deadly serious affair. When Compaq came on the scene I attended their equivalent multi-day training in Houston TX., and it was much more light-hearted - I think they were even then trying to point a finger in IBM's stuffed-shirt image. That was held at the top of one of their 3 corporate tower buildings which were later acquired by HP as part of the real estate in their acquisition; ironically years later as an HP employee I visited that site again. The Compaq was quite an elegant machine and as you have discovered, it was designed to be modular and easily serviced. If I recall, the power supply can be removed without having to remove anything else; the video display was removed by first removing the AC line/switch block and then using a long screwdriver through that opening to reach the screw that is on the side. A funny but true story; the way they taught us how to open the case was to place one of your hands flat on the top center of the case and press hard; this would cause it to bow out a bit at the rear end; then hit it hard with the other hand as a karate chop, all while shouting "Hi-Yee"! That would cause the top section to pop right off and then you could access the innards; same thing with the bottom panel. We actually had to practice this maneuver with the sound effects in unison in class till everyone successfully got their computer cases opened. Later on, when I was working in the store and had to open up a Compaq "luggable" as they were called, I often followed this practice as well, to the great entertainment of store staff. It got slightly more funny when I actually performed the procedure in front of a customer (having judged in advance whether that customer would mind too much). I still have one of these luggables; have not powered it on in 20 years and I'm sure it needs to be re-capped, but it's complete with the co-processor, an enhanced set of cards (AST multiiport serial/parallel) and a 20gb hard drive, which required its own separate controller. I last used it as a "portable serial protocol analyzer; using the serial port with specialized software to monitor the data stream and/or inject bytes as necessary to debug serial peripheral issues. As I recall, the video should display just fine on the build-in screen even with that Composite/CGA card installed; at power-up you should see the memory counting up and then a BIOS message first, then the boot prompt. Switching between the built-in monochrome versus external color was a function key combo. I've got all the manuals for it stashed somewhere in the garage including the service manuals.
@@SproutyPottedPlant I exist since the latter half of ‘83. Born in august of that year. My “firmware” was in it’s early stages of development. Wish I was around a few years earlier to experience the computers from back in they day when they where new.
While working at Compaq (when only campus 1 and 2 existed) we had a version of this for the military with a "Loren" label. If I remember correctly the main difference was a -5 VDC at the serial port for reference. I have no idea why.
I like how this portable computer is basically the size of a 4U rackmountable server lol. But back then this was revolutionary. Now we have the thin wars where everyone tries to make portable devices thinner and thinner, even if it means sacrificing usability.
I used to repair those when they were first introduced to the UK. A fellow engineer used to call them "Barely Luggable's". When I attend the first training course they had us repairing customer returns.
My first ever PC was a Compaq! A Compaq Presario C700, 1GB of RAM, 80GB Hitachi HHD (which still to this day works! But it's slow), an Intel Pentium 1.4GHz dual-core (well, 1.5 core I'd say, the other core was is locked at 800MHz), and shiped with Windows Vista. Yeah it was slow! the Intel GMA graphics could barely keep up. But I used it regularly up to 2011 and occasionally as a backup PC since. I've since upgraded the RAM to 2GB, then later stuck an SSD in it, then later stuck an Intel Core 2 Duo I got on eBay for cheap! It's now almost as fast as a chromebook and runs a Ubuntu derivative with KDE with the compositor effects disabled.
CTRL-ALT-> to use the external monitor is the keyboard shortcut that I found. CTRL-ALT-< goes back to the internal monitor. www.minuszerodegrees.net/manuals/Compaq%20Portable_Plus_286%20-%20Maintenance%20and%20Service%20Guide.pdf
At work, I had full access to the IBM Technical References manuals (both hardware & DOS). The company had a pair of genuine IBM PC/XTs (XT= hard drive, ALL 10MB !!!). For internal use, we made a few "one off" plug in cards, so needed those manuals for reference. When it was time to upgrade to the AT (286), we got a clone. Added IOmega Bernoulli boxes (~8in 5MB kinda floppies, kinda hard drives), with removable media.
I have a 5150 which originally had Datalight ROM-DOS on it. It was a diskless machine which came from the Air Force Base here in Wichita when they were still doing pilot training here. It was used with an interactive cable TV system known as MicroTICCIT.
I had a Tandy 1100 laptop back in the day, very lightweight. It had DOS-on-a-chip along with their Deskmate user interface. I ran Tandy's word processor and Lotus 1-2-3 on it.
I went ahead and dumped the ROM in my Portable. for some reason, mine is blank (FF) until 6000. where the copyright notice starts. I've got a much older unit though (Datecode is 1986)
The 5160 PC XT has a revised mainboard with more expansion slots; it actually set the standard for slot spacing in PCs to this day. It also has a larger PSU for better hard disk support.
When I was 12-13 years old, my dad was allowed to bring one of these home from work for the weekend or evening. I used it to learn how to program in BASIC. Everything was accessed on the 5.25 floppy
Lol Dave .. how can the side panels be made 1994 !! When the chipset is 1984 . ! Does it look like a 1994 laptop ? Gonna start calling you bill Maher. 😜😜😜
I know, "hindsight" and all, but @11:57 I'm looking right at that burned mess at C42 on the floppy controller, clear as day, and I'm wondering how there could possibly be a need to hunt further for the culprit. I feel like I'm watching a horror movie and yelling at the screen "IT'S RIGHT THERE, OMG STOP TALKING AND LOOK, RIGHT THERE!" :D The suspense is killing me
Sorry to Disagree but ... DEC Rainbow 100: May 1982 Dual Boot (CP/M 2.2, MS-DOS 2.11). You can see my DEC Rainbow 100 at the DigiBarn computer museum here: www.digibarn.com/collections/systems/DEC-Rainbow100/page_01.htm . It still booted up when I donated it in 2002.
Calling this a portable is like calling those 90's LAN party tower carry bags a "portable" pc... I wish shipping was cheaper, I have a Compaq Portable SLT/286 here, but I probably will never do a successful teardown video or find a computer museum to take care of this beauty :)
I am trying to repair one now and bought the missing flyback (yeah .. mine come without from previous tech). But still trying to figure out J401 J104. J401 is connected to deflector. What about J104? Look like entire wire is missing. Do you know where J104 should be connected?
I played a Star Trek game in 1974 on a college terminal. It was only 70 KB in size. It used quadrants, sorta like the game, Battleship. I played it so much, the college shut down the terminal (dot matrix printer) I played on. Info: makinggamesbyyear.itch.io/star-trek-1971 Great for kids! Notes required.
I am surprised about that "first pc compatible" claim. In 1982 as an engineer fresh from college, I developped the customer management system for the water and electricity administration of the Comoro islands on a PCcompatible system. I am not sure of the name anymore ( somthing like "Vector"). That system could be set either as a pc/dos machine or as a CP/M machine. In the non compatible mode their "advanced" technology was a variable rotational speed floppy allowing to pack more bits on the outside tracks, allowing to store 1.5MB on a 5-1/4" floppy side! Then I would come home to reverse engineer the ZX80 ROM!
You should do a video on the IBM PS/2 model 50z. The IBM computer that was not IBM-compatible. It was an attempt to bring microchannel architecture to the consumer market. It ran a one-off version of PCDOS that was missing a bunch of standard system calls. I did tech support for a software company back in the day. A user is describing symptoms to me and I knew exactly what was going on. I asked her what kind of computer she had. She said "I'm not going to tell you. If I tell you what computer I have you'll tell me it isn't going to work." Yep. She was right. No other PC would do the things hers was doing. I said "It's a PS2 50z isn't it?" and she got super upset. She was an attorney in an office full of men in 1994 and was under a lot of pressure to prove herself. She ordered an IBM because that was the smart thing to do -- and she ended up with this piece of junk. I'm now a grief counselor "Ma'am, it's not your fault. You did the smart thing and ordered an IBM. The problem is that THIS IBM isn't IBM compatible."
I"ve had a couple of these Compaq sewing machines, one with 486 mothercard, crazy. External CGA output turned on by magic key sequence on keyboard. And i added o 40MB Hd, taking out one of the floppies..
I give this video a 'lousy 9 up thumbs' since THAT is what really matters - up thumbs - up thumbs! Cherry pick positive comments - but throw your own negative ones around- yeah! Get a decent microphone ! Your content is unwatchable - I demand TV broadcast quality audio!
That was my first IBM-clone PC. I built an Altar 8800 kit first and still have it. Then I bough a KIM-1 which was a single-board computer with a hex keyboard so you could load the had-assembled code in one byte at a time. Every programmer should be required to write code by hand to get a good grasp of what the computer is really doing down deep. We called it coding down to bare metal.
Love these old machines. You get much better build quality than you'd see in anything today. But you buried the lead... WTH did the EEVBlog BM786 come from? Did I miss an announcement??
In 1983 I had a vax and that was what I wanted, far superior to my other option, an IBM 370. The PC's did not have enough RAM, were too slow, however they were good as dumb terminals for serial connection to the vax. I can say the PC was superior to the TI silent 700.
At 25:22, you said there is a service for Compaq Portable 286, which is the computer I have. Could you please tell where to find the service manual? "Quote Marks"?? Thank you
23:20, Understandably, you probably need to replace capacitors given the age of that machine. But would you need to replace all of them at the same time or just the ones you suspect may be reaching their end, ie bulging or showing a bit of rust on the top? I'm finding myself having to replace capacitors on both the original Xbox and Xbox360 which have gone rotten while in storage (indoors in plastic containers even), which I assume are both victims of the supposed "faulty caps" pandemic of the 2000's I've seen people write on a few places online. But I've opened up my older consoles, the Segas and the Playstations, and I wonder if I should be rushing to replace their internals as soon as possible, or just monitoring them every couple of years and replacing at the first sign of trouble, or until the inevitable bang? These videos are great! Keep up the good work!
Great video... really liked watching your thought process and troubleshooting methods... of course its the commentary that really makes it enjoyable... thank you... and yes, more repair videos... btw, I love the compaq computers most of the early ones were quality made and well thought out (except for the speaker in power supply module)...
I actually have 4 of these. All dead from blown tantalum caps in the PSU. 2 original Compaq portables. 1 portable plus and one portable 286 (not the portable II 286, I have one of those as well though). I have nearly the full original portable line with perhaps a missing portable 3 as there were several of those. At this point I am scared to turn any system older than a Pentium 2. Too many just go up in smoke.
I remember using a genuine IBM portable back then, 1989-ish, too. I don't recall it being very portable at all. I set it up to monitor activity on a "telecomutting" system I ran when I worked for IBM.
This was my first PC. The hard drive was on a ISA expansion card. Yes is was a long expansion card with a HDD screwed to it. the front section of the card had the controller. I believe it was called "Plus Hardcard 20" for 20mb's. I received it in the early 90's, it was in a large shed owned by my friends parents, they used it at their business but was since retired. They gave it to me for helping clean out the shed. I do recall luging that thing to my friends house that was several blocks away. It was heavy, and I had to stop after every block for a rest. Luckily it was so sturdy I could use it to sit on while I rested. haha
About that time I had another clone of the Compaq. It was called the Panasonic Sr. Partner. It's advantage was an included thermal dot-matrix printer. They called these Luggables!
My Dell PC running Reaper DAW makes digital noise when connected to a sound board or KRK monitor speakers. Noise happens when you move the mouse or when the screen updates. Laptops do not make the digital noise. It may be ground or ground loop issues. How to fix it ??
12:04 I'm staring at the blown up cap and then you say, "well, there we go" and start zooming right to the blown cap so I was sure you found it... then you zoom instead right above it and just say "SMC" and still haven't found it XD
18:29 I see an overheated electrolytic at the right with its 'jacket' retracted near to the low turns adjustable coil bottom. CR413 says on the PCB or something. 20:25 is the ram chip below U37 having magic smoke burns or is it just dust?
PC speaker INSIDE the PSU! you can not say that Compaq did not think inside the box, that the first time i even heard of something so silly. Altho it is box inside larger box so it may be little different inside the box thinking.
Halt and Catch Fire US TV series appears to be based somewhat on the first Compaq clone. Even goes into the creation of the BIOS from scratch without looking at the source code or ROMS. .
ISA bus wasn't plug and play and it sometimes matters what card is in which slot thanks to hardwired IRQ addys. Plug the speaker back in; not passing POST, it's trying to beep a code at you most likely
So from my understanding a computer send electrical pulses to a chip and then it responds in binary code ? How does it display numbers? I have never understood that. I dont know, but I enjoy the channel. How did you take out the ROM chip ?
Hey Dave, would you be interested in a Compaq Portable 386? I was given one by my boss, and I have no clue how he even got it in the first place. Would love to see this on your show. :)
Compaq was by far *not* the first IBM PC clone -- but as they say, history is written by the winners. Columbia Data Products introduced their first IBM PC clone in June 1982, five months before Compaq, and just like Compaq they also used a legal "clean room" ROM rather than an illegal copy of IBM's ROM like some other companies did. But Columbia stopped making PC hardware in 1987, while Compaq lasted until 2001 when they were bought out by HP.
p.s. Bill Gates never said "640K ought to be enough for anyone", either -- especially since when he supposedly said it in 1981, the first version of the IBM PC's ROM was limited to a maximum of 544K of RAM, not 640K.
I owned a Columbia and wrote a lot of code on the thing. It was a good machine at the time.
Didn’t know that. Thanks for sharing.
Yeah, I wish people would stop propagating the idea that the compaq portable was the first IBM clone. MPC1600 owner here! To be fair Columbia Data Products got taken to court by IBM, and IBM won as Columbia had simply copied IBM's ROMs for use in their product (thus violating copyright). Compaq took notice and did their bios/roms by cleanroom so they would not see the same fate. The reason for clones existing at all is a worthwhile read! The MPC1600 was a superior machine every way around the original PC, and you didn't even have to waste an isa slot on your floppy controller as it was built into the motherboard. The motherboard on this thing is HUUUGE by the way! I should really do a video on this thing at some point.
Actually the first IBM PC clone was the Cardiff Electric Giant.
@@cprossu I think you're thinking of Corona Data Systems (later Cordata), who did illegally copy IBM's ROMs and got sued as a result (as did Eagle Computer). Columbia legally "clean room" reverse-engineered IBM's ROMs to develop their own workalike of it, just like Compaq did.
A joke from back in the day...
Q: How can you spot a Compaq user?
A: One arm is longer than the other!
Yep, and that's why it was called a "luggable".
@@darkally1235 It made a good seat on the train, when the carriage was full.
How do I know?
I lugged around a similarly sized Philips P2000C to various hospitals and other customers back in the day. (2x Z80 with optional 8088 co-processor card, ran CP/M or MS/Dos).
It was way more serviceable than that Compaq ever was. A joy to work on. It was about the same size, and almost as heavy.
Kept you fit though.
www.computinghistory.org.uk/det/7130/Philips-P2000C/
The Kaypro 2 weight 13kg the same as the Compaq portable. This way you could get the same long arm but CP/M compatible!
Would appreciate a part 2, enjoy seeing you solve these problems 😀
Yeah I'm all for a Part 2.
@12:00 C42 on the front edge is blown up ! I spotted it immediately.
Good eye!
Its a case of "Live commentary recording blindness". Its common on youtube.
Also C28 behind it.With the close up later I can see it was just scorched.
@@FireballXL55 I reckon that's just a skidmark.
@@agurdel Indeed, I have missed things during recording and only seen them later on too, it certainly is a thing.
19:56 I see one of those socketed ram chips has let the magic smoke out at some point. 2nd one down from the top right.
that was likely where the tag tant was. chip is probably fine
Did you completely miss the burned cap on the floppy controller? Lower left at 11:56
I see it.
Am guessing it just got hit by the tag-tant blowing nearby.
13:43 Wow! That thing has SOVIET parts in it! That EL74LS74 chip was made in the USSR!!!
EL was Soviet export marking of Western-compatible parts.
But they are still recognisable because of font and crappy (usually) brown plastic.
UPD: Oh, there is also EL7438 on the same board
Back then there was a ban on selling computers and the components to Russia, even the ZX80 was banned in case Russia used them as missile guidance systems !
Yes, I just came to the comment section to find out if anyone else catched it! And also a Romanian 7416 on that board, with the 'Beta' symbol on it.
I've seen these USSR export EL74xx chips in Commodore Datasettes and 1541 drives as well! Weird! But I've never seen a Romanian one until now!
@@steverpcb Yes but luckily Z80 CPU was copied in DDR, so the era of self-build computers (and other cool stuff) begin in the USSR too.
@@mrnmrn1 Thank you for the information about the chip with "Beta" logo.
I suspect it was from Eastern Europe but newer thought that it was from Romania.
I am not sure was this FDD originally installed in this Compaq or it was installed by the owner. Searching Web I found this:
www.ebay.com/itm/Siemens-Model-FDD111-5-Floppy-Disk-Drive-PN-S22742-A1115-C001/372854101030
You could see that the floppy drive and PCB is the same but this one has Siemens sticker and all Western IC in it.
Perhaps, this FDD was designed by Siemens, WST was one of OEM maker and Siemens allowed them to sell overproduced devices by their own brand - so they bought the cheapest parts they could ever find? Just a theory...
@@steverpcb In early 1980s they had PDP-11 copy en.wikipedia.org/wiki/1801_series_CPU
Dave, there was a blown Tam cap C42 on the floppy board just below the big brown Caps C23 & C24
I'd figure he knows, since he points it out and talks about it at 22:45.
@@JLsoft It was _incredibly obvious_ and he even zoomed in at an IC not far from it which had an obvious bit of debris, the top of the blown tantalum type cap he was just talking about moments before, just below it, so looking at the camera's LCD instead of directly at the PCB may have been why he missed the obvious.
@@winstonsmith478 I'm so confused..what do you mean by 'why he missed the obvious'? Are you talking about Dave? ...Because _Dave_ is the one that focuses on that area, points out the problem, and talks about it in the first place for the first time ever...which is why I replied to a reply that was...pointing out the blown cap, as if they thought Dave didn't see it.
Is there some earlier alternate version of this video that you both saw where 22:45 _doesn't_ have Dave talking about that specific blown cap, saying that it lines up with the sparks he saw, etc?
@@JLsoft first seen at 11:54 - Dave points to a bit of analoggy goodness and misses the blown tant C42.
@@docpaul D'oh, okay...didn't realize there was 15 seconds of him showing the card before actually 'looking' at them :/
I’m pretty sure this is the system that the first season of Halt and Catch Fire was based on.
Yup it certainly is. Great show for anyone interested in this era of computing, through the 90's.
11:35 Waxes lyrical about replacing tantalum caps. Next shot, point directly at blown tant. Then spends the next 10 minutes tearing computer apart looking for it. Classic Dave
Hi my guess is he saw it, but being on the floppy controller ( an accessory card ) the pc should still boot up but not have a working floppy. Sort of like say a 26/486 with a faulty isa sound card - they system will boot and run but not that sound card - unless that cap is now a direct short to ground
@@georgemaragos2378 nah, he would have explained that if he saw it. He explains everything he sees even if it's not relevant
I remember when I was planning my purchase of my first PC, I was agonizing over whether to get a 286 or wait until I could afford a 386. A teacher told me that there was no reason why I would ever need the computational power of a 386.
Thing is, if you can afford it, sometimes its nice to have extra power incase you do end up needing it (especially for future proofing).
While most people should be fine with 8-16GB for gaming, I do a lot of other things too that end up eating up RAM so thats why for my PC I built it with 64GB of RAM (which is nice because we're already starting to see games that want 16 or 32GB for the recommened specs)
@@nekomasteryoutube3232 8 hasn't been enough for gaming for a while 16 is now what any gaming PC should have with atleast 32 for streamers/ youtubers
I'm 12 mins in and screaming at my phone about the blown tant on the floppy controller near all the analogue stuff. I hope he finds it.
This kind of audience engagement is what the algorithms crave.
@@illustriouschin What if creators know this and do it deliberately? :-/
@@EEVblog that's the kind of thinking of a psychopath youtuber hahahaa. Just kidding, love you man!
@@EEVblog You've done it in several videos and it's just F**king annoying.
@@mfx1 You're free to make your own EE teardown and repair videos.
"Pin 19 is the clock on the 8088".. 🤣 is it sad for electronic engineers when can remember pinouts of chips without a dataset. I still remember a lot of the 4xxx cmos and 74xxx told pinouts. So sad 🤣
I once got offered a job because I could answer the guys questions off the top of my head about what various 74xxx chips did. He was amazed, LOL. Standard hobbyist knowledge.
@@EEVblog Nice :) I think you mentioned that once on AmpHour with Bil Herd interview. I remember this as my favourite amphour ep. I miss my C128D. :)
I used to work for Bill Herd in PCM Systems Integration!
Anyone else pointing at their monitor saying 'Dave look at the ram chip with the blown hole in it!' lol (u44) 20:23
Those unpopulated rom-slots could also be for ROM BASIC.
PhotonicInduction: "Ohhhh I popped it"
some people will never understand this ref - almost a cult reference at this point on the internet.
@@CrazyLogic I get it :) wish he would still make videos, he was Dave's evil twin
Til it Pops!
@21:24 I didn't know that DMA controllers were in charge of refreshing DRAM! Ahhh what would've been of the 8088 if it only had a direct-memory-access controller, and not a DRAM controller. hahahaha
Used to work for Walt Russell, employee #7 at Compaq, he designed much of the case and peripherals for that machine. He left Compaq when it became essentially TI all over again...
LOL. I was Compaq employee #3879 in my twenties. We used to snake various portal parts out of the MFG complex and reassemble while pounding beers.
Second column from right, second row, of the ram below u37 @20:36 looks like it's lost its magic smoke. Looks nicely cratered.
Nicely spotted, but it was just some crud or something, it's gone now, so maybe when I used the air duster or I was reseating the chips.
@@EEVblog automatic suspicion of old ram on my part. :)
I think I'd be carefull about committing too much to odyssey. Napster War 2.0 is inevitable. You don't have to look very deeply to find the New Napster, and it's way easier than Kodi Pi.
If it fails it fails. I'm on half a dozen different platforms.
How can this happen? 37mins full of Compaq beauty but no clip with John Cleese? Bummer!
Regards,
Etna.
Damn...
Going to bet the power supply fault is a shorted electrolytic capacitor that provides the POK signal. Generally the power supply had a RC circuit that gave the POK, and had a simple comparator in there that was connected to the power supply controller power, and then compared the unregulated input to the chip with the reference, So that when the input was below around 8V from the 12v power rail, the comparator would pull the POK low to hold the processor in reset. LM311 with the output connecting direct to the pin and ground, and a pull up to 5V, with a capacitor to provide a turn on delay before the reset was released. Reset switch also just shorted out this capacitor to provide the same thing.
Hi - some machines are funny the 12 and 5v specs are sometimes just done on the feeds of the power supply before the board , while others specifically overvoltage the power supply as they are designed to have a final or stable 12 / 5v on all components on the mother board after the power drains by mother board , video card, floppy card , hard drive
Regards
George
7:20 - whatever happened to "don't turn it on - take it apart!" ?
Ah the first Klingon computer on earth...
The Com Paq! I still have my 860cds 486
21:11 burn mark on the mainboard pcb by the pin 1 of the blue chip...
When that came out I was still in high school, and they had just gotten a whole room full of Apple ][ machines. First room in the school that had barred windows, and a door with a second security gate, plus there was always a teacher in there when it was open.
"take you mind back to 1983 early 1983, what where you doing?" ah yes i was quite busy not existing
According to the show "Triumph of the Nerds" CPM could have been the OS of choice. But the owners of Digital Research (not sure of name) turned down IBM's confidentiality agreement. So IBM turned to the programing languages supplier, Microsoft.
12:05 floppy board, is that an exploded cap at the bottom left?
I hired on as Service Manager in 1979 to Store #85 of Computerland, which was a chain of retail stores all over the U.S. - this one was in Sacramento CA. I worked for the local franchise which grew to 5 stores in northern California till 1987. I went to many service training seminars over the years including at IBM for the original PC. That one was held at one of their labs and was a week-long, deadly serious affair. When Compaq came on the scene I attended their equivalent multi-day training in Houston TX., and it was much more light-hearted - I think they were even then trying to point a finger in IBM's stuffed-shirt image. That was held at the top of one of their 3 corporate tower buildings which were later acquired by HP as part of the real estate in their acquisition; ironically years later as an HP employee I visited that site again. The Compaq was quite an elegant machine and as you have discovered, it was designed to be modular and easily serviced. If I recall, the power supply can be removed without having to remove anything else; the video display was removed by first removing the AC line/switch block and then using a long screwdriver through that opening to reach the screw that is on the side. A funny but true story; the way they taught us how to open the case was to place one of your hands flat on the top center of the case and press hard; this would cause it to bow out a bit at the rear end; then hit it hard with the other hand as a karate chop, all while shouting "Hi-Yee"! That would cause the top section to pop right off and then you could access the innards; same thing with the bottom panel. We actually had to practice this maneuver with the sound effects in unison in class till everyone successfully got their computer cases opened. Later on, when I was working in the store and had to open up a Compaq "luggable" as they were called, I often followed this practice as well, to the great entertainment of store staff. It got slightly more funny when I actually performed the procedure in front of a customer (having judged in advance whether that customer would mind too much). I still have one of these luggables; have not powered it on in 20 years and I'm sure it needs to be re-capped, but it's complete with the co-processor, an enhanced set of cards (AST multiiport serial/parallel) and a 20gb hard drive, which required its own separate controller. I last used it as a "portable serial protocol analyzer; using the serial port with specialized software to monitor the data stream and/or inject bytes as necessary to debug serial peripheral issues. As I recall, the video should display just fine on the build-in screen even with that Composite/CGA card installed; at power-up you should see the memory counting up and then a BIOS message first, then the boot prompt. Switching between the built-in monochrome versus external color was a function key combo. I've got all the manuals for it stashed somewhere in the garage including the service manuals.
What was i doing back in 1983, busy not exsisting.
I think my parents were in middle school
I just about existed then, puking and pissing around the place 🤮
@@SproutyPottedPlant I exist since the latter half of ‘83. Born in august of that year. My “firmware” was in it’s early stages of development. Wish I was around a few years earlier to experience the computers from back in they day when they where new.
While working at Compaq (when only campus 1 and 2 existed) we had a version of this for the military with a "Loren" label. If I remember correctly the main difference was a -5 VDC at the serial port for reference. I have no idea why.
I like how this portable computer is basically the size of a 4U rackmountable server lol. But back then this was revolutionary. Now we have the thin wars where everyone tries to make portable devices thinner and thinner, even if it means sacrificing usability.
Compaq Portables always reminded me of sewing machines in the cases that were often used for them.
It's been a long time since I was treated to "Essence of Allen Bradley." Lovely aroma.
I just got one of these. Possible dead power supply. Wish me luck.
Like Your enthusiasm, Dave, for saving piece of history! :) Waiting for part two..
The Compaq part on the CGA controller is probably the character set ROM.
We used to have those at work, we called them "luggable" not "portable"
Wow, I have several of those antiques in your introduction. IBM tech manuals were amazing. Even sharing source code for a lot of the BIOS.
Every time I see the keyboard through the case, part of my brain thinks “gee the texture mapping guy’s gonna get a talking to about that one”
Sherlock Jones. Love these mystery fault finding videos!
I used to repair those when they were first introduced to the UK. A fellow engineer used to call them "Barely Luggable's". When I attend the first training course they had us repairing customer returns.
But at the time, they were Luggable. It's only now do we see it as Barely Luggable.
Repair video is also fun to see, especially repair these retro-machine.
Tight as a nuns what? I almost spit my coffee. Gg Dave. You won this round. 😆
Took note of that, for future use !
This PC was my very first PC. Purchased it at a used computer store not really knowing what I was getting into! :D
See it missing the 8087, but then that was a $500+ option
My second work pc! First being the original IBM... damn I feel old.
I was 17 in 1983 and I feel old.
I had a Compaq Portable III, not sure if I still have it. I possibly do, at PODS. I've also got some kinda IBM portable that looks a bit like it
Would love to see you do a full repair on this iconic computer. (on this channel, please).
My first ever PC was a Compaq!
A Compaq Presario C700, 1GB of RAM, 80GB Hitachi HHD (which still to this day works! But it's slow), an Intel Pentium 1.4GHz dual-core (well, 1.5 core I'd say, the other core was is locked at 800MHz), and shiped with Windows Vista. Yeah it was slow! the Intel GMA graphics could barely keep up. But I used it regularly up to 2011 and occasionally as a backup PC since. I've since upgraded the RAM to 2GB, then later stuck an SSD in it, then later stuck an Intel Core 2 Duo I got on eBay for cheap! It's now almost as fast as a chromebook and runs a Ubuntu derivative with KDE with the compositor effects disabled.
Compaq Portable forum - compaqportable.org
HALT AND CATCH FIRE ❤️
CTRL-ALT-> to use the external monitor is the keyboard shortcut that I found. CTRL-ALT-< goes back to the internal monitor.
www.minuszerodegrees.net/manuals/Compaq%20Portable_Plus_286%20-%20Maintenance%20and%20Service%20Guide.pdf
At work, I had full access to the IBM Technical References manuals (both hardware & DOS). The company had a pair of genuine IBM PC/XTs (XT= hard drive, ALL 10MB !!!). For internal use, we made a few "one off" plug in cards, so needed those manuals for reference.
When it was time to upgrade to the AT (286), we got a clone. Added IOmega Bernoulli boxes (~8in 5MB kinda floppies, kinda hard drives), with removable media.
We called it "CREEP" when reseating the chips
I have a 5150 which originally had Datalight ROM-DOS on it. It was a diskless machine which came from the Air Force Base here in Wichita when they were still doing pilot training here. It was used with an interactive cable TV system known as MicroTICCIT.
Really looking forward to the repair!!
Give this PC to CuriousMark
I had a Tandy 1100 laptop back in the day, very lightweight. It had DOS-on-a-chip along with their Deskmate user interface. I ran Tandy's word processor and Lotus 1-2-3 on it.
I went ahead and dumped the ROM in my Portable. for some reason, mine is blank (FF) until 6000. where the copyright notice starts. I've got a much older unit though (Datecode is 1986)
"Hi, take your mind back to 1983..."
DIVIDE BY ZERO EXCEPTION USER WAS NOT BORN IN 1983
The 5160 PC XT has a revised mainboard with more expansion slots; it actually set the standard for slot spacing in PCs to this day. It also has a larger PSU for better hard disk support.
When I was 12-13 years old, my dad was allowed to bring one of these home from work for the weekend or evening. I used it to learn how to program in BASIC. Everything was accessed on the 5.25 floppy
Lol Dave .. how can the side panels be made 1994 !! When the chipset is 1984 . ! Does it look like a 1994 laptop ? Gonna start calling you bill Maher. 😜😜😜
a team of engineers?🤔 what?😳 are you telling me that wasn't mackenzie davis who reverse engineering the ibm bios?. 🙄 Damn AMC!, they lied to me 😰
In 1983 I was using the Portable. My parent's worked at Compaq and they were allowed to bring one home every night.
I know, "hindsight" and all, but @11:57 I'm looking right at that burned mess at C42 on the floppy controller, clear as day, and I'm wondering how there could possibly be a need to hunt further for the culprit. I feel like I'm watching a horror movie and yelling at the screen "IT'S RIGHT THERE, OMG STOP TALKING AND LOOK, RIGHT THERE!" :D
The suspense is killing me
Sorry to Disagree but ... DEC Rainbow 100: May 1982 Dual Boot (CP/M 2.2, MS-DOS 2.11). You can see my DEC Rainbow 100 at the DigiBarn computer museum here: www.digibarn.com/collections/systems/DEC-Rainbow100/page_01.htm . It still booted up when I donated it in 2002.
No streaming platform exclusive videos, thanks.
Calling this a portable is like calling those 90's LAN party tower carry bags a "portable" pc...
I wish shipping was cheaper, I have a Compaq Portable SLT/286 here, but I probably will never do a successful teardown video or find a computer museum to take care of this beauty :)
I am trying to repair one now and bought the missing flyback (yeah .. mine come without from previous tech). But still trying to figure out J401 J104. J401 is connected to deflector. What about J104? Look like entire wire is missing. Do you know where J104 should be connected?
I played a Star Trek game in 1974 on a college terminal. It was only 70 KB in size. It used quadrants, sorta like the game, Battleship. I played it so much, the college shut down the terminal (dot matrix printer) I played on.
Info: makinggamesbyyear.itch.io/star-trek-1971 Great for kids! Notes required.
I am surprised about that "first pc compatible" claim. In 1982 as an engineer fresh from college, I developped the customer management system for the water and electricity administration of the Comoro islands on a PCcompatible system. I am not sure of the name anymore ( somthing like "Vector"). That system could be set either as a pc/dos machine or as a CP/M machine. In the non compatible mode their "advanced" technology was a variable rotational speed floppy allowing to pack more bits on the outside tracks, allowing to store 1.5MB on a 5-1/4" floppy side! Then I would come home to reverse engineer the ZX80 ROM!
You should do a video on the IBM PS/2 model 50z. The IBM computer that was not IBM-compatible. It was an attempt to bring microchannel architecture to the consumer market. It ran a one-off version of PCDOS that was missing a bunch of standard system calls.
I did tech support for a software company back in the day. A user is describing symptoms to me and I knew exactly what was going on. I asked her what kind of computer she had. She said "I'm not going to tell you. If I tell you what computer I have you'll tell me it isn't going to work." Yep. She was right. No other PC would do the things hers was doing.
I said "It's a PS2 50z isn't it?" and she got super upset. She was an attorney in an office full of men in 1994 and was under a lot of pressure to prove herself. She ordered an IBM because that was the smart thing to do -- and she ended up with this piece of junk. I'm now a grief counselor "Ma'am, it's not your fault. You did the smart thing and ordered an IBM. The problem is that THIS IBM isn't IBM compatible."
I"ve had a couple of these Compaq sewing machines, one with 486 mothercard, crazy. External CGA output turned on by magic key sequence on keyboard. And i added o 40MB Hd, taking out one of the floppies..
I give this video a 'lousy 9 up thumbs' since THAT is what really matters - up thumbs - up thumbs!
Cherry pick positive comments - but throw your own negative ones around- yeah!
Get a decent microphone !
Your content is unwatchable - I demand TV broadcast quality audio!
That was my first IBM-clone PC. I built an Altar 8800 kit first and still have it. Then I bough a KIM-1 which was a single-board computer with a hex keyboard so you could load the had-assembled code in one byte at a time. Every programmer should be required to write code by hand to get a good grasp of what the computer is really doing down deep. We called it coding down to bare metal.
Love these old machines. You get much better build quality than you'd see in anything today. But you buried the lead... WTH did the EEVBlog BM786 come from? Did I miss an announcement??
What was I doing in 1983? Not existing, wasn't born until 1985 myself... :P
In 1983 I had a vax and that was what I wanted, far superior to my other option, an IBM 370. The PC's did not have enough RAM, were too slow, however they were good as dumb terminals for serial connection to the vax. I can say the PC was superior to the TI silent 700.
At 25:22, you said there is a service for Compaq Portable 286, which is the computer I have. Could you please tell where to find the service manual? "Quote Marks"?? Thank you
23:20, Understandably, you probably need to replace capacitors given the age of that machine. But would you need to replace all of them at the same time or just the ones you suspect may be reaching their end, ie bulging or showing a bit of rust on the top?
I'm finding myself having to replace capacitors on both the original Xbox and Xbox360 which have gone rotten while in storage (indoors in plastic containers even), which I assume are both victims of the supposed "faulty caps" pandemic of the 2000's I've seen people write on a few places online. But I've opened up my older consoles, the Segas and the Playstations, and I wonder if I should be rushing to replace their internals as soon as possible, or just monitoring them every couple of years and replacing at the first sign of trouble, or until the inevitable bang?
These videos are great! Keep up the good work!
Great video... really liked watching your thought process and troubleshooting methods... of course its the commentary that really makes it enjoyable... thank you... and yes, more repair videos... btw, I love the compaq computers most of the early ones were quality made and well thought out (except for the speaker in power supply module)...
I actually have 4 of these. All dead from blown tantalum caps in the PSU. 2 original Compaq portables. 1 portable plus and one portable 286 (not the portable II 286, I have one of those as well though). I have nearly the full original portable line with perhaps a missing portable 3 as there were several of those. At this point I am scared to turn any system older than a Pentium 2. Too many just go up in smoke.
IBM screwed themselves over by publishing their Technical Reference Manual.
Even the BIOS asm listing was printed in the appendix.
I remember using a genuine IBM portable back then, 1989-ish, too. I don't recall it being very portable at all. I set it up to monitor activity on a "telecomutting" system I ran when I worked for IBM.
You won't take anything without a blue usb port, but you are trying to get that thing working. Maybe some collector's value?
This was my first PC. The hard drive was on a ISA expansion card. Yes is was a long expansion card with a HDD screwed to it. the front section of the card had the controller. I believe it was called "Plus Hardcard 20" for 20mb's. I received it in the early 90's, it was in a large shed owned by my friends parents, they used it at their business but was since retired. They gave it to me for helping clean out the shed. I do recall luging that thing to my friends house that was several blocks away. It was heavy, and I had to stop after every block for a rest. Luckily it was so sturdy I could use it to sit on while I rested. haha
About that time I had another clone of the Compaq. It was called the Panasonic Sr. Partner. It's advantage was an included thermal dot-matrix printer. They called these Luggables!
My Dell PC running Reaper DAW makes digital noise when connected to a sound board or KRK monitor speakers. Noise happens when you move the mouse or when the screen updates. Laptops do not make the digital noise. It may be ground or ground loop issues. How to fix it ??
12:04 I'm staring at the blown up cap and then you say, "well, there we go" and start zooming right to the blown cap so I was sure you found it... then you zoom instead right above it and just say "SMC" and still haven't found it XD
This remind me of elementary where we used floppy disk
18:29 I see an overheated electrolytic at the right with its 'jacket' retracted near to the low turns adjustable coil bottom.
CR413 says on the PCB or something.
20:25 is the ram chip below U37 having magic smoke burns or is it just dust?
PC speaker INSIDE the PSU!
you can not say that Compaq did not think inside the box, that the first time i even heard of something so silly.
Altho it is box inside larger box so it may be little different inside the box thinking.
Halt and Catch Fire US TV series appears to be based somewhat on the first Compaq clone. Even goes into the creation of the BIOS from scratch without looking at the source code or ROMS. .
ISA bus wasn't plug and play and it sometimes matters what card is in which slot thanks to hardwired IRQ addys. Plug the speaker back in; not passing POST, it's trying to beep a code at you most likely
i had one of them ... super good ... the succedor 286 had started with BIOS on HDD and then the whole problems begun ...
So from my understanding a computer send electrical pulses to a chip and then it responds in binary code ? How does it display numbers? I have never understood that. I dont know, but I enjoy the channel. How did you take out the ROM chip ?
Before this came out I built a clone from a kit sold by Netronics. 100% clone - even ran on IBM BIOS ROMS if you could get them or make them. ;)
Hey Dave, would you be interested in a Compaq Portable 386? I was given one by my boss, and I have no clue how he even got it in the first place. Would love to see this on your show. :)