The Most Powerful PC of 1977: Best of the Best!

A full hardware walkthrough of the best-of-the-best for 1977: RAM, ROM, EPROM, Disk Controllers, Graphics and more! Dave shows you the assembly and testing of the MOS KIM-1 Stack.

[@dwightelvey645]

I'd bought a KIM-1 years ago from a fellow that had reversed the +5v. Needless to say, even with the diode to protect the board it still wiped out both the 6502 and the 6530 -002 that has the monitor in it. Diagnosing what is wrong was a pain so I created a diagnostic board to check things out, one at a time. The 6502 was easy to get but the 6530 -002 is a custom chip. These were only made for the KIM-1. I created a 6532 to 6530 replacement module, similar to some of the schematics found on the web. I made it a little more universal by putting the decode on a PAL and the ROM code goes in a small EEROM. I miniaturized it all to fit under the 6532 on 2 small boards. Using the PAL, I have it select to be either used as -002 or -003. I use the diagnostic board I made to program the EEPROM. A long story short, I now have a working KIM-1. I'd have loved to have the KIM-1 setup you have but it is way out of my price range.

[@MatthewHarrold]

Random trivia ... I'm about 15 years out of coding for a living, tried the prime sieve using XCode on my 2013 MacBook Pro in C++... typo'd to find the first 1 million primes instead of all primes less than 1 million. First run was instantaneous, no output to terminal, second run (after printf fix) was aborted after 17 minutes when my laptop started to sound like a Lear Jet taxiing to the terminal in high wind while having an asthma attack. I need more practice ... you lose these skills without constant effort. Thanks Dave. $0.02

[@kamilkurzynowski3836]

You should buffer the output and display it with single print :)

[@javabeanz8549]

That reminds me of what I did in JavaScript, I was writing my own Sudoku board, but I ended up with calling routines on every part of the board when I only meant to check the one that was currently active. Once I fixed my logic error, it went to working faster than I could tell, from bogging down to seconds after I clicked. And it was much worse trying to use a phone or tablet, compared to the i7 laptop.

[@MatthewHarrold]

@Kent Teffeteller no, in 2013 is Intel thru and thru. Reading comprehension is required for a meaningful contribution.

[@Voodoodrul]

I just started doing SDE2 work at Microsoft working on parts of Azure. My childhood was centered around the MS-DOS 5.0 and Windows 3.0 era. Thanks, Dave, for your part in making that all possible. I love seeing hands on tinkering with low level hardware.

[@monad_tcp]

wtf is SDE ? Systems Designer Engineer ? seems like a cool job to have on Azure. I love Azure and I have to always preach over those eek AWS people.

[@Voodoodrul]

@@monad_tcp Software Development Engineer. A mostly Microsoft acronym

[@Uberalles02]

I enjoyed this, and look forward to seeing the KIM-1 fully functional!

[@vcv6560]

What a blast from the past; 1977, 2007, 2017 and beyond. @Dave, Debugging never changes. Your 'retirement' looks like so much of my 30 years of work: What doesn't that work, it used to!. Oh as a passing observation its obvious Steve Wozniak would have a thing or two to say about that disk controller board!

[@paulscarlett4346]

What memories! Back in 1977 - was a Waterloo Comp-Sci Co-op Student working in downtown Toronto where I saw my first IMSAI and KIM-1 ... but I was broke -- so could only drool over the hardware -- and buy the current version of Byte magazine and wonder. Now after 40+ years in Process Control Software development -- I look back these "computers" and realize that even though I didn't own one, reading and learning was worth even more than what I was learning at Waterloo at the time. Great Times.. PS. please do a video on your connection with the Friendly Giant. Thanks

[@javabeanz8549]

My eighth grade graduation present was a BASIC programming class, done on an IMSAI and a Poly 88. And yes, I had my stack of BYTE magazines, and later Computer Shopper.

[@daishi5571]

I love these old systems they remind me of where we came from in computing and electronics. I built an old Sinclair ZX81 kit on my parents kitchen table but even that was modern design compared to this despite only 4 years separating them. On the shoulders of giants.....

[@DMahalko]

I would recommend adding some power rail LEDs directly visible along the top edge of the backplane, so you absolutely know it's off when swapping boards.

[@stevhutch3835]

You go Dave. My KIM-1 is from 1979. Developed a real-time synth and sequencer. Using Pittman Tiny BASIC. I hope to resurrect it soon.

[@willynebula6193]

Any videos? I'd subscribe and watch for sure.

[@kartakhalsa]

Around 1978 I took a computer science course at U Mass Amherst which taught assembly language programming using the KIM-1. So this video was a blast from the past!

[@JeordieEH]

Thanks for the video. I would love you to get this machine running in it's full glory. Please continue this series.

[@darkwaveatheist]

I've been working in IT for 30 years. This computer came out 1 year after I was born. Bloody hell, I thought Sun Microsystems Forth based firmware thing was weird. This is utter voodoo!

[@randaldavis8976]

join the forth group and enjoy the weird on every processor

[@uploadJ]

Back in those days, it was called "data processing" too.

[@chriswareham]

I used to have a SPARC based laptop (basically a SPARCstation 5 compatible). I wanted to put NetBSD on it, but had to hack the firmware in Forth to get it to read the boot floppy. Definitely weird!

[@darkwaveatheist]

@@chriswareham Was that Tadpole SPARCbook by any chance?

[@chriswareham]

It was an RDI machine, although I think RDI was later bought out by Tadpole.

[@btsoomcb]

This brought back a lot of memories of repairing computers starting in 1969. I've seen a lot of boards like the one in the KIM-1. Thanks Dave.

[@btsoomcb]

@Dave’s⊕①⑦①⑧⑨⓪⑤④⑧⑤⑦ Signed up ... Rely enjoy watch all your videos. I really wish I had learned more than Cobol and RBP (Not a type of game) along the way.

[@davefarquhar8230]

I'm definitely looking forward to the next installment of this!

[@davidgari3240]

I must be crazy, but it's like watching a crazy old person - who knows EXACTLY what he's doing, accomplish the near impossible. You kids give me hope for the future.

[@davidgari3240]

Getting Bill Gates' BASIC running on an Altair 8800 from cassette was a similar feeling...

[@davidgari3240]

Daddy, what's an Operating System? -Digital Research just released CP/M. -Is that like VMS? Go to bed, Dear.

[@SeaMower]

Back in 77, I was a tech at the USCG Electronics Lab in Alexandria, VA supporting Honeywell DDP-516 16 bit minis with 8K core memory, paper tape, and model 35 teletype connected to NAVsat, LORAN-C, and OMEGA receivers for navigation on icebreakers and oceanographic cutters. That year, the Lab bought a PET and an IMSAI 8080. As I recall, they had 4K semiconductor RAM on the IMSAI. But the build of the S100 chassis was somewhat flimsy compared to the MilSpec DDP-516 or even the PDP 8e we also had. By 1978 we were using TI Silent 700's with built in tape for paper terminals, and ADM-3A's for CRT terminals. I would think the IMSAI would be more powerful in many ways.

[@robertekis2450]

Ahh, this reminds me of my first debug monitor for a bit-slice based processor board. I had 2K of 64-bit instructions contained in PROM (got expensive making updates until we got the ROM emulator working). I was fortunate in having a dual UART for serial coms. Boy, that was a fun learning experience (I was fresh out of college and was lucky to get assigned something this complicated that soon). I started with a new HW design and empty PROMs and a great mentor to help me when I got stuck. Thanks for bringing those memories back, Dave.

[@thesoundsmith]

I loved the basic KIM-1. HAad it under a perfboard setup in a briefcase building analog synth interfaces by hex hand coding. Had NO idea what I was doing but it was great fun. Then I saw one controlling a bunch of students linked to a mainframe at Stanford working on what would become the Yamaha DX-7 digital synth. I had no idea they had created their own cottage industry.

[@Wonk_Bonk]

Amazing video Dave! These videos were you go and tinker with hardware from back in the day is very fascinating!

[@amyslittlehelper]

Wow, what a trip down memory lane (pun intended)! I had a KIM-1 for a while in the late 70's, learned a lot with it. I remember the MTU boards and expansion cage, had a friend at the time that build up the whole collection. Looking forward to seeing you get all of this up and running! Oh, and thanks for writing the book. Diagnosed late in life, the book helped put some of the pieces and some of my life experience in order.

[@captainsunshine918]

As you dive deeper into the Kim-1 it all goes further and further over my head... Yet my interest grows as well. I enjoy all of your videos but this series especially.

[@jimroselli8487]

Thanks Dave. I’m dusting off my KIM 1 now and will get it working, You inspire us with these videos…

[@alexandermaasland3494]

Thanks a lot for sharing this Dave! I really like this old-school hardcore computing video:)

[@michaelcarey]

This is a fantastic video Dave! I'm fascinated with computers of this era, the nuts and bolts do-it-yourself hobbyist machines. I'm old enough to remember seeing ads for the KIM-1 in electronic magazines... but I didn't jump into home computers until the C64 came along. Seriously thinking of building a replica KIM-1.

[@mikemartinell]

Two thumbs up. Awesome seeing you work through the issues. Keep them coming - I'm really enjoying the series!

[@richardjarvisiii]

I like that you show the errors and issues as you run into them.

[@StationGarageSt]

Love watching a clever man getting lost but NOT GIVING UP! The superlative bit is your stream of consciousness narrative. Fascinating.

[@rickthorp8363]

Fantastic video, I found myself watching your screen lights that were displaying the audio of your voice while you were explaining things, and it was enough visual with the audio to really keep me in touch with your explanation as you were moving along.

[@henryyoung7184]

Love this - takes me back to my teens when I would drool over magazines with the latest micros back in the day. I ended up building my own 6809 based system with a hex keypad and 8 digit 7-segment LED display with monitor not much better than the KIM-1's default. Then I got access to a PET with BASIC & FORTH and never looked back.

[@paulcottingham241]

Hey Dave. I had a KIM-1 and had a lot of fun with it. I never souped mine up though. I with I still had it!

[@stewarttunbridge]

Back in the day I built up a system around the 2650 processor and blank matrix boards. It eventually had 24k RAM 2k video RAM my monitor and compiler (super simple language i created). Thanks Dave

[@TheComputerChip]

I am greatly enjoying this KIM-1 series. Keep it coming! Windows 95 was my first OS and as such computers existed differently than the KIM-1 by the time I was around. I am finding this series awesome for understanding the VERY basics of computers and how we went from loads of 74 series chips to the hardware of today. Wish I had a floppy drive for ya!

[@javabeanz8549]

W95, so you missed most of the "fun" of jumpers for IRQ, DMA, Port addresses, and the like to get video, sound, modem and such to all play together nicely. Plug n play devices were becoming the norm by then. I couldn't tell you how many computers I built back in those days, but I had a lot of jumper settings memorized, and knew which cards had the most flexible settings.

[@wp5355]

I enjoy looking at older technology, because I worked on some of it during the seventies with a company called Pertec Computer Corporation where I worked on tape and disk drives. I was a hardware tech.

[@duanepaddock7685]

Really enjoying the KIM-1 episodes. Thanks Dave.

[@michaelpezzulo4413]

I really like watching you have fun. Makes me want to dive in deeper.

[@procryton4171]

Very cool. I'm certainly enjoying it! I love older tech, though I have never seen anything quite like this.👍

[@AZOffRoadster]

I built my first computer back in 1976. An RCA Cosmac Elf with 256 bytes of ram. It controlled my xmas tree lights that winter.

[@tekvax01]

You have made another excellent video Dave! We all blow things up every now and then... I remember a nice Mackie audio mixer I was repairing. Whilst reconnecting everything, I got one of the cable headers seated off by one contact, that promptly sent +48 volts phantom power to the +15 volt rail of ALL 50 or 60 of the OpAamps on the board... I recalled an old adage... "If you drop your keys into a river of molten lava, don't fret it, man, cause they're gone!" Indeed I had fried every single OpAmp on the circuit board, dozens of them! Oh well... live and learn my friend! :) I hope you can get the memory card up and running again. If I can help, please drop me a line.

[@martinwhitaker5096]

I guess that one went in the never-to-be-repaired pile! I have a Mackie tt24 waiting for my attention... Seems to have some kind of PSU issue. I had hoped the power supply would be a simple affair but it's a huge complex beast with a million outputs :-(

[@TimePilot2084]

I watched the entire video from start to finish. I rarely watch an entire KZbin video. I love troubleshooting hardware, especially old tech - they didn't have those blasted SMDs back then! I can barely see them, how can I be expected to solder them?! Good stuff, can't wait to see the next one!

[@willofirony]

Excellent! Don't hesitate to publish similar in the future.

[@jonty2020]

Great video, the KIM1 deserves this kind of coverage.

[@kenworks6068]

Great content Dave, I was able to follow along and reminisce of my early hardware. You are much better at this than I was. I should now go fix my home brew Apple-II clone.

[@MRCNC1967]

I've no idea what's going on beyond power supply and stuff, but hey, it's entertaining and a joy to watch old hardware come to life, keep up the good work!

[@roelvoort]

Great content, most of it goes over my head but very interesting. Top job on the "Enhanced Zoom" (magnifying lens) video insert, made me smile.

[@tassiebob]

Enjoying the KIM-1 videos - as you've mentioned, this one must be the most expanded KIM-1 of it's time!

[@MrStillions]

I personally missed this when it launched but I love these types of videos. I would love to see more like this if it something you wanted to do more. :)

[@retiredump7038]

My "PC" in 1977 was a TI-59 Programming Calculator, with the magnetic card reader. I could actually write/run most of my freshman Fortran class programs on my '59.

[@wkgmathguy218]

There was a Fortran compiler for the TI-59????? As I remember I could only program in a 'language' that mimicked calculator keystrokes. Funny enough there is a Fortran compiler for my phone...

[@retiredump7038]

@@wkgmathguy218 Not writing in Fortran, but testing the algorithm for my Fortran assignment. Saved a lot of time troubleshooting. Writing for the TI-59 was very similar to Assembly Language. I even wrote my own Adventure Game for the 59 and a version of Hangman where the calculator cheated and always "guessed" correctly.

[@mechaform]

Fascinating. Thanks for sharing your KIM adventure.

[@jacobjake683]

Very interesting to see how this old hardware works.

[@jk180]

All good stuff Dave. Thank you. Can't wait to see you running some serious code on the KIM1

[@monkey_see_monkey_do]

This was EPIC! Thank you, Dave! KIM-1 is my favorite computer for all times!

[@JeremyGabbard]

I enjoy watching folks show off working vintage computers - the knowledge preservation is neat, even if I don't have any goals of learning how to do it myself :p

[@DaveManDaveDude]

Really enjoyed this episode, thanks Dave.

[@jschwenker1]

I thoroughly enjoyed watching you troubleshoot.

[@rickclapp6560]

I hadn't heard much about the KIM1. Impressive. I build an IMSAI 8080 back in 1977. I still have it and it works. It used the Processor Technologies CUTTER tape drive interface. The only issue now is the tapes for loading the OS are bad so I can't boot it up. I wish I had spent the money to get the EPROM with the OS. Oh well...

[@jwc4520]

Dang it , I was hanging , then your memory proved once more, superior to what's left of mine...lol then the 70s were a considerable time ago. Still enjoyed a trip through my youth. Thanks.

[@jimlawson629]

Another great video Dave! Looking forward to the next one, I hope you can get the ram expansion boards working.

[@Ariannus]

I'm a huge fan of vintage computer content. Hope to see more.

[@lesliedeana5142]

I got sucked into the Z80 world and stayed away from 6502 stuff, and in a way regret it now (Hatfield vs McCoy's mentality at egret time) and really enjoy this series. Yes, please keep going...

[@howardwilliams2587]

Love it!!!! Great memories of my younger days building S100 based systems. Also reminds me of my Heathkit PDP-11 WITH paper tape reader. The trials and tribulations of troubleshooting - thanks a ton for sharing!

[@stuart4858]

Great stuff Dave, keep these coming..

[@Brianreese83]

Love your channel. found out im biopolar and autistic in my 30s. your channel speaks to me even if I cant code. computers have always fascinated me, wish I had done more with the coding side in life but its never too late to learn I guess. keep up the good work I am learning a lot, even if it is light years ahead of me. I have a physics background so the math wont be the worst thing for me. Wish I knew where to start with the basics. have been told java script is where to start if you want to make money selling mobile apps but thats also so far ahead of me its not even on my radar.

[@monad_tcp]

The "bios" or "system" or whatever it is called is literally a debugger. I loved it. And the fact that there's no online documentation makes it even better. Online not meaning internet, but online as microsoft called it. Want documentation for you 16K machine, that's dead tree documentation.

[@takingbytes1265]

I love this series about the Kim 1! Makes me want to get my hands on one!

[@stuartogrady8787]

One of your best videos, I can't wait to see if you get all the boards working and what can be done on this machine.

[@Pyyhekumi]

After 7 minutes of watching this, I was glad we got the Plug n Pray tech.

[@evanbarnes9984]

I love that you're running Linux on a virtual machine running on Windows, all running on Mac pro hardware!

[@HoJoGoGo]

There are adapters on eBay that will convert the 50 pin shugart 8 inch floppy to 34 pin, so you can use regular HD 5.25 drives (1.2 meg) with the 8 inch controllers, as well as allow you to use a gotek floppy emulator flashed with flashfloppy. That should allow you to test/troubleshoot with something more modern than a 40 year old 8 inch floppy drive.

[@DavesGarage]

I bought one, it arrived today. I also have a GoTek somewhere, it would be cool it it all worked!

[@Vallee152]

I'm fascinated by that audio peak visualiser thing that was sitting behind you on the desk

[@DavesGarage]

Thanks, I'm working on it as a project for the channel one day!

[@skf957]

Love it, thanks for sharing. More like this please.

[@RudysRetroIntel]

Really cool seeing this technology again. Forgot a lot of it but your video is bringing things back from long storage memory. Love the Friendly Giant TV show reference at the end :)

[@kencreten7308]

That was fantastic. Thank you, Sir.

[@DavesGarage]

Glad you enjoyed it!

[@SeanBZA]

@@DavesGarage Yes, it is great. As an aside TTL is really rugged, you will probably only find one or two failed gates, though more than likely your issue is open circuits, either cracked solder joints on the pins, or bad IC sockets that go intermittently open. I have had an entire computer have a power supply issue, with the unregulated 14V being applied for a few hours to the 5V logic, 2 cascaded failures of the overvoltage crowbar not working any more, and something in the 5V regulator going bad. Of the 500 or so TTL IC's on the various boards, only one actually failed, a PM5403 quad open collector NAND gate. Easy to see once the board was pulled, the lid had unsoldered itself. The computer itself was still fully functional, just had a single detected fault, in that the self test light went out immediately. Guess what that IC controlled. All functional otherwise, even the 2708 PROMS were fine, along with the custom Intersil DAC in the 40 pin purple ceramic, and the Mostek MK4007 RAM chips.

[@malectric]

BTW, this brings to mind a common problem back in the day which still persists and gets worse with time and exposure to the atmosphere. Any tinned chip pins corrode (terribly in some cases). I fix it by either removing the sockets and soldering the chips in after cleaning the pins, or simply cleaning the pins and sockets by first scraping the pins with a scalpel then applying a decent contact treatment. Pulling the chips out and replacing them in the sockets helps. I'm sorry to report that a couple of years ago I gave a bundle of old machine stuff to a museum including a couple of Shugart 8" floppy drives that I'd head cleaned and aligned and tested. Sorry again. Someone out must have some. Regarding the RAM boards (and a lot of old (NMOS) chips besides), the order of applying multiple voltages to the circuits matters. And I'd be tempted to check the voltage regulator outputs with a scope to make sure the regulators aren't dropping out or oscillating.

[@chrisbenedictum1]

Hi Dave, another Dave here lol. The retired electronics tech in me wanted to help in the shop... thank you ! Have a great one, "for those who like to rock"... 😎🖖🤘.

[@rickkephartactual7706]

I started with computers in the very late 70's and love the challenges and learning. However, as good as the memories are I would never want to have to go back to that. LOL We have it so good now. Most people have no idea what it was like in the early days. I never had to use punch cards or paper tape thankfully. Its scary to think what it was like with punch cards and heaven forbid you dropped them and got them out of order!

[@losergamer04]

OK, too interesting to watch during work hours. Saved for later!

[@wtmayhew]

That brought back memories. When I was an undergrad, I took an assembly programming course which oddly combined 360/370 mainframe assembly and also 6502 targeting the KIM-1 using a cross assembler on the 370 punching the output on IBM tabulator cards. A grad student had cobbled up a table top card reader from Polypacks which sort of worked. We had to key in a bootstrap from the KIM-1 keyboard to read the cards. It was almost impossible because of the horrible key bounce on the KIM. Grrr! My assignment was to play Jingle Bells on the KIM speaker. It kinda worked, pretty out of tune. The debug cycle was horrendous having to wait hours to get your output deck punched and pick it up from cranky person at a window.

[@stupossibleify]

You and the "Commodore History" KZbin channel are really shining a light on the KIM-1 at the moment!

[@specialc]

Good work. My first assembly language course was 6502 assembly on the kim 1. I am getting a kick out of these videos.

[@MajorMandyKitten]

I love seeing old tech like this, and the history behind it. also, it seems like there's a high pitched whine in some of your audio.

[@daveruble5150]

I don't have a clue what you're doing, yet I enjoyed watching you talk about doing it. Mission accomplished; I suppose, eh?

[@3dmaxuser]

Great video Dave .. more please 😁

[@jbloodwo]

Dave this this really needs some kind of hardwood base. Also this series has been lots of fun to watch

[@saultube44]

Super interesting 🤔 Never heard of this type of computer, very primitive, I guess that's the way back then, what a nightmare: needs automation so it's more practical to use. Enjoying you struggles with old computers, that I'd had struggle with back then. Keep up the good work 😃👍

[@HughPlaysGames]

Super interesting! Thanks Dave

[@kevincozens6837]

Dave, the ttyUSB* devices are part of the dialout group. Instead of changing the group of the device to be owned by you you should add yourself to the dialout group. You will need to relog for the Linux system to recognize the changes in groups associated with your account.

[@IncognitaLabs]

I fondly remember the COSMAC ELF, switches on the front to enter data, a build it yourself affair.... No Asperger's or autism but OCD ... yup. Great videos my friend!

[@ed.puckett]

Good content, good attitude! Your channel rocks!

[@DavesGarage]

Thanks for the kind words!

[@rjy8960]

This brings back so many memories of playing with the 6502 and writing self modifying code. Nice Daytona :)

[@CTCTraining1]

Fascinating stuff, thanks very much Dave. Only thing I’d beg is to avoid bright moving / flashing lights in the background of shot, other than that a very enjoyable journey. Maybe an opportunity for a youtuber collaboration on repairs ... several good folk breathing new life into early 80’s machines. Keep up the great work 😀👍

[@Phuqem]

Always enjoy your trips to the way back machine!

[@twobob]

yay the little chair! Boo the board being finicky. Common wisdom might say check for marginal caps. That seems like a relatively easy adapter board to build but I am no wizard. Although it seems to just need 2 sides, a little planning, some measurements and vias to handle the flip. The clockspeeds don't seem to need any fancy planning. The power lines seem to be the same size as every other line so probably just echo that. You can build up the outline of the shape in inkscape and provide the .dxf to to get the complex outer shape in EasyEDA. Hope it helps. For everything else there is calipers...

[@TheInternetHelpdeskPlays]

I can almost see Adrian Black clawing around the screen.

[@wtmayhew]

If you want to see something truly weird do a search for the RCA Cosmac VIP. It was a single board computer, also from 1977. The processor was the RCA Cosmac ELF 1802. It was a very strange CPU. The claim to fame of the 1802 was that at the time, it was the only CMOS microprocessor. That made the 1802 amenable for aerospace and space applications because CMOS is more resistant to radiation than NMOS, NMOS being the common microprocessor technology back then. One of the projects in a lab where I worked was to build something going into space using an 1802. The project was another person’s domain, so that’s all I know. I know he had a Cosmac VIP board on his desk.

[@MinhasA]

Hi Dave, I'm a recent subscriber and I am not a CS major, but Ive always been into computers... I am teaching myself c++ as an adult after failing as a kid. I just want to say I really enjoy your vids and this one is definitely awesome. I am subbed to CuriousMarc, Adrian Black, etc and I definitely get into this vintage hardware. I am not the typical individual, so I wouldn't be surprised if I'm in the minority.. but from me at least it's all positive feedback :)

[@DavesGarage]

Thanks! Good luck on learning C/C++! It can feel steep at first, but the more you do... the more you know!

[@MikelNaUsaCom]

Enjoy the journey! Hope you are enjoying the adventure.

[@glasser2819]

Dr. Dave: do you have a SCOPE handy?? This will help you see if the power supply is indeed capable of handling all the load forced upon it. All the obvious round .1uF caps darting the logic boards are helping to iron the HF switchings smooth. Double check your distributed power is still clean under load as capacitors do age. A cap-meter needs cap to be desoldered out.. so practically scope or replace works best . 👍

[@uploadJ]

re: "Dr. Dave: do you have a SCOPE handy??" THIS always bothered me about these S/W types; they NEVER use test equipment! No Scopes no logic analyzers - not even an old HP single bit 'logic probe' that can at least show 'bit wiggling'!! In my day, a Tektronix 475 on the bench was standard equipment ...

[@JamesPotts]

@@uploadJ A 475 was standard for a home hobbyist? Mine cost a small fortune, used, bitd. (Not that Dave can't afford a scope.)

[@uploadJ]

@@JamesPotts re: "A 475 was standard for a home hobbyist? " Yeah ... since the 80's ... I've since upgraded to a Tek 2430, TDS320 and an older HP ZOOM feature digital scope ... I bought several scopes thru the 'country store' at Texas Instruments where Wally Wallace (who ran the store) sold used test gear to employees ... some of the gear req'd minor to major repair depending on what Equipment R&M (repair and maim) techs did to the gear during calibration or repair ops.

[@glasser2819]

good software needs great hardware to run without time consuming glitches These days we are spoiled with extreme reliability only spoiled by obsolescence factors 🤪

[@uploadJ]

@@glasser2819 re: "needs great hardware to run without time consuming glitches" True that. I was surprised that Dave wasn't using Deoxit (or even WD-40, which is what I use) on those card edge connectors. I even use WD-40 on memory sticks today, and have done so since 386/Win 3.1 days.

[@davep9565]

Great video!

[@martindejong3974]

Obviously there were no IBM-PCs in 1977, so this is not about one! I also started with the KIM-1. In 1977 Byte magazine published the first three real computers sold in shops, the "trinity of 1977", the Apple ][ the TRS-80 Model 1 and the commodore PET which was a direct descendant of the KIM-1, designed by the same person. Unfortunately I only have three issues of bytes from Volume 2 (1977), February, march and december. A 1MHz 6502 doesn't make a KIM-1 the most powerful of the four. but perhaps the most expanded one can be seen here. always fun to watch.

[@DavesGarage]

It's not an IBM PC (nor did I claim that!) but the KIM-1 really was a "personal" computer when the others were targeted more towards the office. I'm measuring power by ability, not raw computation, to be sure!

[@martindejong3974]

@@DavesGarage I got that, but by your reasoning the Apple ][ was also a Personal computer, and it had color and sound, in 1977, I think that speaks for its capabilities.

[@jimstand]

Old bytes are available at worldradiohistory dot com and then click on the byte magazine link.

[@mnoxman]

Yup. Pretty much a day in the life of a early personal computers. The Altair, IMSAI and the "Model I" made it from fighting flaky hardware in to a platform you could program on.