Would appreciate a part 2, enjoy seeing you solve these problems 😀

A joke from back in the day... Q: How can you spot a Compaq user? A: One arm is longer than the other!

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.

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.

@12:00 C42 on the front edge is blown up ! I spotted it immediately.

Dave, there was a blown Tam cap C42 on the floppy board just below the big brown Caps C23 & C24

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.

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

I’m pretty sure this is the system that the first season of Halt and Catch Fire was based on.

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...

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.

Compaq Portables always reminded me of sewing machines in the cases that were often used for them.

Really looking forward to the repair!!

Like Your enthusiasm, Dave, for saving piece of history! :) Waiting for part two..

It's kind of neat to see some of the things I was playing with way back when. Thank you.

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

That was great! Looking forward to part 2 and the PSU diagnostic work.

Can't wait for part 2!

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)...

Repair video is also fun to see, especially repair these retro-machine.

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.

In 1983 I was using the Portable. My parent's worked at Compaq and they were allowed to bring one home every night.

Go for it Dave!

Anyone else pointing at their monitor saying 'Dave look at the ram chip with the blown hole in it!' lol (u44) 20:23

Amazing thanks Dave, i love the 8-bit era home machines so these IBMs are like mega machines to me. Cool as.

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.

Excellent. Thanks!

@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

Sherlock Jones. Love these mystery fault finding videos!

I want one of these so bad. Or any "luggable" computer really. Great video mate, I'm excited for part two.

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

That case is deceivingly tough. I used my dad's through college and even checked it on a plane once. It got banged around a lot and never broke.

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.

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

i wias just given one of these yesterday in absolutely amazing condition . aside from its psu :) did the exact same thing as yours did previous owner turned it on and pop . other then that it is perfect :) cant wait to get inside and clean it up and repair it

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.

I recall using one of these in our university ham radio club. I was listening to the Hurricane Net and typing the coordinates of Hurricane Gilbert into some program which let you track the progress of the storm. How things have changed!

Looking forward to a part 2

I became an IBM and Compaq certified technician in 1984. Brings back lots of memories, not all rosy.

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.

I'm trying to imagine myself standing all day at a repair bench next to Dave listening to him as he diagnoses and repairs stuff lol

I had one of these! Had to buy it used in 1987 but man I loved it. Had a Hercules board in it.

"take you mind back to 1983 early 1983, what where you doing?" ah yes i was quite busy not existing

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.

PhotonicInduction: "Ohhhh I popped it"

Thats amazing!

My Compaq Portable is my profile picture! I am in the process of rebuilding the keyboard. All the pads are shot. My great-grandfather bought it back in the mid 80's and when he passed, I got it.

Awesome sauce

Ahh Greenbushes tantalum mine. Used to live down the road from there about 10 years ago. Nice visit from the old lookout(Down the road in Australia = 50 kilometres)

Would love to see you do a full repair on this iconic computer. (on this channel, please).

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.

The Compaq part on the CGA controller is probably the character set ROM.

an authentic relic is amazing :)

used to field service these. Covers could be tough to get off sometimes. Remember cutting my fingertips on one once getting the lip of the covers open. There was also a Compaq special cranked socket tool for removing a near inaccessible bolt that held the psu in place.

Had on of these and two of the IBM 5455 luggables. Much preferred the IBMs.

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.

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.

Sifting through all your videos waiting for you to reference the specific piece of information I want to learn is apparently more efficient than using Google.

I owned one of these for a few years in the 90s - it had been heavily modified by previous owner. Although this was originally an 808x machine, mine had a daughterboard in one of the ISA slots with a '286, and the really goofy part, a ribbon cable running from that board that plugged right into the original CPU socket. Talk about an interesting "bodge". Sold it to a buddy just because it was so huge, but I do wish it was still in my vintage hardware collection. I had originally found it at a new/used parts store where I was buying my very first Ethernet card. That didn't even come with a boot ROM but was nearly US$200 back in the early 90s.

It's been a long time since I was treated to "Essence of Allen Bradley." Lovely aroma.

Oh hell that brings back bad memories of lugging one of those to customer sites. It ran a network sniffer we used in troubleshooting.

Those unpopulated rom-slots could also be for ROM BASIC.

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.

kids like me born in 2000 will never appreciate the awesomeness of the old computer systems especially how analogue they are

Hi and great video, I really enjoyed it, the IBM compatible systems we used to see a lot of back in the early 80's as well as the IBM systems were the Sperry XT and Sperry AT units, those were great little machines but they were marketed as desktop systems so not portable, not sure if Sperry ever made a portable unit but if they did I never saw one..... boy those were the days.

This PC was my very first PC. Purchased it at a used computer store not really knowing what I was getting into! :D

the Compaq Luggable! I grew up playing Rogue on DOS1.0a on one of those.

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.

I saw one of these at a rummage sale years ago, from a distance, and honestly thought it was a toaster oven. It wasn't until later I realized what it was, and I vaguely regret not walking over and taking a closer look.

I went full "Once Upon a Time in Hollywood DiCaprio meme" at 11:58

The parity was at the top, says so on the silk screen!

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”

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!

I've taken one of these apart. The CRT can be powered off a molex connector. I had it hooked up to a Pentium machine effortlessly. I remember watching Terry Gilliam's "Brazil" and wanting to build a bare bones terminal, like they had in the movie, and this was perfect source of parts. If I knew these computers were going to become such rare (and expensive) collector items, I wouldn't have thrown the rest of the machine out, which was in perfect working order. I wanted to make the original videocard shorter, so I sawed it in half along the division line right in the middle. Sadly I then discovered that it was a multi-layer board and I was never able to re-link the middle layer properly. After that I discarded the CRT as well. Regret it to this day.

And these units were still more fun to dismantle then the damn candy-macs.

I had one and my brother worked for them in Toronto.

Great video with excellent troubleshooting and circuit tracing. Looking forward to the second one, I have one of these Compaq portables in my basement. The computer starts up and has a floppy and a hard drive. The issue on these (spoiler?) is that the aluminum pads on the keyboard deteriorate making the keyboard non-functional. It would be interesting to see the state of this one.

Nice Video and I still have the same compaq to restore here. Greetings from CPUGALAXY

I had a Corona "portable" that looked similar to this. Good memories....

Got one of them in the loft!

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.

My second work pc! First being the original IBM... damn I feel old.

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

Still have my IBM PC tech manual. Used it to design a couple of PC slot cards in the day.

I still have my 8088 made by Hyundai! It was an IBM compatible with a hercules/cga graphics adapter and a monochrome monitor. Amazing times back then! :)

I wrote QBasic on these things - hot stuff at the time and had a snazzy Compaq graphic.

Just seeing your oscilloscope in shot there - made me realise that it's got more CPU & storage than the computer you are working on!

I remember that machine (or one like it). I hooked up an 8" drive with CPM. so many years ago now.

Part 2 please !!

I've never even HEARD of the MacCharlie before, but I want one now. Gonna have to find another Mac Plus to go with it, but those are easier to find. That Charlie's gotta be even more rare than the Lisa!

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.

21:11 burn mark on the mainboard pcb by the pin 1 of the blue chip...

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..

Second column from right, second row, of the ram below u37 @20:36 looks like it's lost its magic smoke. Looks nicely cratered.

Part 2 please. 😁

LOL I have one of them with a HD. Got it as a cast off from a friend's company. Still booted a couple years ago.

i remember helping my dad carry in a paper bump from this thing. he was asked to go thought the code for the people he worked for. he stored the dump on the stairs much to my mother annoyance.

7:20 - whatever happened to "don't turn it on - take it apart!" ?

It would be very interesting to see how they've done the pcb layouts back in the 1980's...

Dave, once you get the system going and the VDU working, you may have to press Ctrl-Alt "" on the keyboard to toggle the graphics mode to/from 80x25. That should get you composite output from the graphics card.