I Bought the Oldest PC on eBay! Unboxing the KIM-1

Dave finds, receives, unboxes, repairs, tests, and writes code for the oldest home computer listed on eBay: a MOS KIM-1 Rev A Micro Computer System (MCS) of 1976.
For information on my book, "Secrets of the Autistic Millionaire":
amzn.to/3diQILq
My other channel, join now so you're there for episode 01!
/ @davepl
Discord Chat w/ Myself and Subscribers: / discord

[@hbengineer]

I am currently restoring MY first “PC” a SYM-1 that I bought using money I earned working after-school jobs in high school. The SYM-1 is the cooler big-brother to the KIM-1. Thanks to the internet, I have an early Microsoft Basic for it in addition to the Resident Editor Assembler (REA) and even a C cross-compiler! I taught myself 6502 machine language back in the day using a “BYTE Magazine Programming Pad” which was a paper form you could write out the assembly code and then hand assemble before typing in the hex digits. I’ve built a custom expansion board that boosts the SYM-1 to 64K of super-cap backed SRAM and the aforementioned ROM images which I can switch in and out of the memory map using dip switches. I’ve built a remote keypad and hex display using modern ‘real’ keys. I’ve programmed many computers over the years but I’ll always have a soft spot for my first!

[@larryk731]

My dad had a sym1 and wire wrapped a 16k ram board and a keyboard and terminal interface. I (as a young kid) helped. lol. I remember a teletype Asr33 at 110 baud with a paper tape reader and upgrading to a 300 baud video terminal. This was around 78/79.

[@DunnickFayuro]

But... can it run DOOM? ;P

[@larryk731]

@@DunnickFayuro With my dads knowledge at the time he could have probably succeeded- lol

[@hbengineer]

Sorry, never got into Doom… One of my after school jobs in high school was translating BASIC adventure games from one dialect of BASIC to another. Mostly between AppleSoft and TRS-80 BASIC but I did spend some time with the Commodore PET and the TI-99/4. I think I’m fortunate to have the experience in programming 6502, Z80, 6809, 68000, and 8086/80286 assembly language. But my first was 6502 machine code before I saved up enough money to buy a 6502 assembler that ran on the Apple ][ but I was only able to use after school to assemble my SYM-1 programs…

[@radiolabworks]

My SYM-1 is still running today with 64K Ram and interfacing to the old Commodore floppy drives. Even have it connected to the internet via a LAN to Series Port adapter. Roll with the times ;)

[@herdware]

Very interesting actually seeing a "fully expanded" KIM-1. Hoping to see more videos about the other cards.

[@derekchristenson5711]

I know, right? I've seen plenty of photos of the KIM-1 before, with its tantalizing two edge connectors, but always connected to nothing for some reason. A large cage with linked dual backplanes and a bunch of cards? Neato!

[@GeoffRiley]

Such happy memories! The first micro I laid hands on was a KIM-1… before that it was all Hollerith cards and a long wait! I got quite adept at entering 6502 in hex, and later when I got a job with Tandy I was still entering hex but for the Z-80 instead. Computing was so much simpler back then… when we could look forward to running our own nuclear power stations from home! 🤣

[@henryyoung7184]

KIM-1 was my first object of computer lust, but I never got past studying it in magazines with my kiddy pocket money budget too limited. The first 6502 machine I actually touched was a Commadore PET, and the first I owned was a BBC Micro. I then went on to design and build my own 6809 system, complete with hex keypad and 7 segment LED display. I loved 6809 assembly more than 6502. Oh the nostalgia ...

[@JeremyNasmith]

I'd love to see a deeper dive into what the rest of the boards do, and how the former user thought to expand the KIM - 1. Fascinating stuff!!

[@davidbonner4556]

On my first job out of High School an Engineer let me play around on his Commodore Pet during lunch (1977). My second job (1978), as an engineering tech I taught myself 6502 machine code on a Kim-1. About 6 months after starting we had Rockwell come in and train all of us on their new Aim-65, one of the 3 big single board 6502 systems. The company only wanted to keep 3 Aims for the lab so I bought the one I used for $300, $75 off of list price. The Aim was unique in that it came with a full keyboard, 20 character 16 segment led display and 20 column thermal printer, and allowed Mnemonic code entry although you had to calculate your own branches.

[@videcomp]

I loved the Aim-65 and built a number of industrial controllers based on it. This was the system I upgraded to after using the SYM-1 for a few years. These were the days where programs were stored on analog audio cassette tapes. We interfaced the AIM-65 to a custom A/D board that was connected to a pressure sensor. When we moved our office to a new location near a college, suddenly our calibration routine stopped working. I spent several days trying to sort the problem out. After midnight it worked perfectly. During the day and evening absolutely erratic. I accidentally unplugged the cable leading to the cassette deck so that the next time I tried loading the calibration program into the the AIM-65, instead of the program loading, the audio was played out the cassette deck's speakers. Not only did you hear the obvious programming tones (think modem sounds in old movies), there was also a strong music track. These tapes had never been used for anything but the AIM-65. That led to the discovery of the calibration problem's cause. We were located across the street from the campus's student radio station. The signal from their broadcast was so strong it was killing our calibration and adding music to our recorded programs. The solution was to only calibrate instruments after midnight when the radio station was off the air.

[@sefarkas0]

Sine wave on one crystal pin is totally normal. The square wave comes from a digital output which has lots of harmonics, the crystal is like a super good filter at one frequency so you only see one ‘tone’.

[@dmacpher]

TIL

[@SianaGearz]

Mhm but if the CPU performs certain operations on rising or falling flank of the clock, when is it exactly in a sine wave? So aren't you supposed to prepare the clock by turning it into a square wave, amplify, Schmitt trigger, before you feed it to a digital circuit?

[@sefarkas0]

@@SianaGearz inside the cpu is a circuit the drives the crystal and gets its input from the crystal at the same time (sort of an amplifier) the driving side is a square wave and is used by the cpu, the sine side just goes back to the input of the circuit.

[@SianaGearz]

@@sefarkas0 Oh so the 6502 has the crystal drive and the digital clock generation built-in; Z80 does not and i think 6510 might not either, or at least is normally used with an external clock circuit maybe for cycle stealing shenanigans.

[@sefarkas0]

@@SianaGearz z80 and 6502 do not have a built in crystal clock circuit. Back then they used external sources usually with more than one clock signal (phase 1 phase 2). Modem cpus have a the oscillator built in and you supply the crystal externally. They are labeled in and out, the square wave is on the out pin.

[@jurjanbrust]

Wow, looking forward seeing this episode. The KIM 1 is such an iconic piece of hardware. Too bad Chuck Peddle passed away. I am currently reading the book 'Commodore - A Company On the Edge'. The late 70's and 80's were such fascinating times.

[@jeffnay6502]

I actually had a 6' vinyl banner made with a pic of Chuck Peddle along with a short blurb about the 6502.

[@jurjanbrust]

@@jeffnay6502 do you have pictures? Would like to see it.

[@jeffnay6502]

@@jurjanbrust Click on my KZbin channel, by simply clicking on my name, I have one playlist dedicated to the KIM-1.

[@jeffnay6502]

Hey Dave, looks like you received your KIM-1 and are already having fun with it. SWEET SYSTEM !!! You can always stop by my place, here in Florida to see a KIM-1, with all white ceramic chips and an Altair 8800. Remember there is a bug in the early 6502 where the ROR command does not work. Give it a try, so that you know if you have that problem or not. Don't forget to first set your interrupt vectors ($1C00) at both 17FA-FB and 17FE-FF, so when you press ST or RS, they are pointing to the correct location and will actual work.

[@brandonupchurch7628]

I've been watching a lot of Tech Time Traveller, he's done a lot of videos on old micro computers and terminals that are great, Usagi Electric has been doing a series restoring a mini computer, he recently got it to boot and was able to use the testing operating system to edit hex values in memory and then execute it.

[@exidy-yt]

I've been following Usagi's quest to restore that ancient Centurion minicomputer, it's amazing how much he's gotten to work considering the hard drives were both crashed beyond all hope of repair (which is prob. why he got it for $300) and with the help of that guy who had the diagnostic board and some amazing helpers in his discord, it's up and running code now. All he needs is a storage solution and the Centurion lives again!

[@KingSlimjeezy]

usagi is the kind of man I aspire to be like when older.

[@sryx]

When I was in 1st grade my mom took me with her to a night class where she was a learning machine language. I remember clearly playing with a computer like this. I just built an IMSAI 8080 replica now I think I'm going to have to try and track down a KIM-1 :)

[@lilyward4094]

I love seeing these old machines working, thanks Dave.

[@channelzero2252]

I'm always amazed by old hardware. I'm in my 40's and I built my current computer but these days it's like assembling Lego as the hardware side is mostly done for you.

[@alexthelion335]

It's nice that the hardware is taken care of so it's more accessible, but nowadays if you want to know about the hardware you're using(how it works) you basically have to go back to microprocessors like these

[@c1ph3rpunk]

If you want the ultimate experience, build Ben Eater’s 8-bit computer. The term “computer” is really loose there, you’re in fact building a processor using gates, designing the instruction set and implementing it all using chips and breadboards. It’s a blast.

[@nathanjohnson9715]

@@c1ph3rpunk I have my ben eater SAP1 framed and hanging on my wall. It's my most prized possession, and I learned a TON building it.

[@Peter-House-Jr]

Makes me want to get out my Kim 2! I have the one I purchased in 1982 (?) and still have the manuals and even some assembly worksheets I made at the time. I actually made a commercial product using the Kim 2 and purchased several hundred! Thank you so much for all of your very entertaining videos.

[@Peter-House-Jr]

Oops! Spoke to quickly and had a senior moment: I have a SYM-1 made by Synertek Systems Corp - Everything else is true ! I have never seen a KIM, only heard of them. The SYM-1 is very similar to the KIM-1 only the board is bigger, the keyboard has more buttons, there is room for more RAM, and room for additional ROM chips. Mine only has the built in monitor ROM and no basic although I believe there was a BASIC ROM available. I wrote in Machine / Hand Assembly.

[@markpitts5194]

@@Peter-House-Jr And now we all want some history to this. None of us are ever going to be Dave, but even an 'amateur'(!) video would be well received. Honest, no matter how bad the vid, we would love to see it.

[@adrianstephens56]

Thank you, Dave. Brought back memories. In 1978-ish, I took delivery of a 6502-based system with a hex keypad. It was the Acorn system 1. I got it from 4a Market Hill, Cambridge. There were a bunch of long-haired types on the landings between floors soldering and assembling systems. Of course, Acorn eventually invented their own processor and became ARM, still based near Cambridge. An acquaintance of mine in the metal physics group at the Cavendish was Herman Hauser, who ended up big in ARM. I was astonished at the power of the 6502. My data point for comparison was a PDP-8S (s= serial), which had a 1MHz clock, and took 13us to do anything. It had a 12-bit word, a 12KW main memory and a ~40kW fixed hard disk. It could read paper tape at 500 cps. I learned the paper tape boot loader, which I had to toggle in on the front panel. It occupied (one or two, can't remember) 19-inch rack-mount 6-foot high cabinets. The advantage of the PDP-8s was when it broke (which it did), I could test all the (germanium) transistors on a multi-meter and replace the failed unit. It's amazing what you can program in 12KW. In my first paid software job I was told "Adrian, we were waiting for somebody with PDP-8 assembler, we've got this little job for you.". The little job involved modifying a "bright beer" manifold control system in a brewery (Carlsberg). They had >100 parallel threads of operation ("open valve, wait 5 hours, close valve") crammed into those 12KW. Where's this going? Nowhere, but I'm retired and have official sanction to meander...

[@davidjohnston4240]

That crystal - the sinusoid output is the undriven leg. The square wave is from the chip that is feeding back to the crystal.

[@jackgerberuae]

The wave did not look very square to me…?

[@IanSlothieRolfe]

@@jackgerberuae That may just be how Dave had his probes attached. If they weren'r grounded close and on x10 then the square wave will appear to have slopes and ringing, the signal on a crystal is easily distorted by adding abnormal loading.

[@jackgerberuae]

@@IanSlothieRolfe thanks 👍

[@davidjohnston4240]

@@jackgerberuae Normal Gibbs phenomena and the non linear aspects of the TTL output and the frequency depending load contribute to the shape of the wave.

[@michaelterrell]

@@jackgerberuae They rarely did, since it drove an unterminated line. It looks even worse without something like the Tektronix P6201 900MHz FET Probe, which was made for scopes like the 2465 series. it is very high impedance and has a very low capacitive loading which won't affect the signals. I needed one when working on some 68340 based embedded controllers to find crystals that were operating in the wrong mode.

[@DanielMReck]

I've never gotten a particularly close look at a KIM-1, so this was really great. I appreciate you including your learning curve with the pinout and such -- it's important to remind folks that a mixture of careful work and mistakes is how we learn in a healthy way. Looking forward to an entire series of deep dives on this system!

[@MoseleyJaguar]

As a fellow Aspi, and Canadian (don't say the last part too loud), love your content.

[@alangunn7254]

That was great!:-) I was in my teens in 1979 and had been an electronics enthusiast for some years. I looked longingly at the KIM 1 and planned to get a z80 based Nascom (It had a qwerty keyboard.!) and I saved my first pay working on motorway construction. By the time I had enough, the Acorn Atom had become available. I bought one in Kit Form and later spent £125 on the extra 6k of RAM to allow bit-mapped graphics! Great to see a KIM1 lighting up! Thanks!

[@GeoffRiley]

The first visit I made to the BBC at Oxford Road in Manchester loads of the technicians had Nascoms buries in nest of wires, getting them to do fancy things with video signals… it was bleeding edge stuff back then: now you could do similar things with a phone! 😆

[@terrenceryan8773]

Hearing the phrase "Current Loop and Rs-232" transported my mind back 40 years

[@jimbesselman7939]

This brings back fond memories of my first steps. You're inspiring me to dig out my old KIM-1 and MTU boards and power them up. It was always an exciting day when Micro the 6502 Journal would arrive in the email for hours of entertainment.

[@roberthillkg5wry206]

Great video! The KIM 1 was my first computer. I added memory and hand wire wrapped a display card. Added a keyboard interface. This was while I was in an electronic technician school. A recruiter from Texas Instruments came by and I showed him my setup. He hired me on the spot. After a BSCS degree (paid by TI) and 40 years of writing embedded code I retired from the company. The KIM 1 changed my life.

[@corkybenson8104]

In 1974 in an EE Class at CMU we had a lab to make a sine/ square/ sawtooth variable frequency signal generator from a KIM-1 and a DAC. Hand built assembler code. Tough.

[@Cyril29a]

I love stuff like this. I just spent 14 minutes watching a man add two plus three and it was fascinating.

[@loupasternak]

lol

[@johnfuller760]

This vid has inspired me to dig out the Kim-1I bought in 1978. Thanks Dave.

[@annihilatorg]

"Now I can move on to Page 3!". I've been bingeing on old Kit computer videos recently so this is just feeding that current obsession.

[@arminth]

This is an incredible find! Especially the amount of documentation is worth it's weight in good! Congratulations and have a lot of fun!

[@XBary_PL]

You could say that this is a must-read for any programmer. Supposedly insignificant toys today, but when you think about it, it is the foundation of what we spend most of our time with today. :) Greetings from Poland

[@joncorso6103]

Super frickin cool to see this. The Kim 1 was my intro to computing back in the 70s. Not the actual computer, but I took out a book from the local library on machine language programming the 6502 and it was all Kim 1 based. Stoked my lifelong love of computers and programming. Until now, had never actually seen one.

[@ianmcpherson2301]

Processor was also used on the BBC Micro which had a whole matching TV series about computing. I have one of the originals from that era.

[@crunchyeater]

Ooo we at it with the esoteric content! Love it.

[@fredflintstone8048]

Nice find! I love the form factor. I've always had a sort of 'fetish' for card cage systems. I spent decades programming, and doing general repairs, and board level repairs on 8080 based card cage PLCs built in the late 70s that were used to run a utility plant, and all the HVAC and lighting systems in all the buildings. The last of which were decommissioned only a few years ago. For their era they were highly robust and one of the models was a dual controller system that could sense certain faults on one side and fail over to the other side where the code had been automatically loaded.

[@cscheong8048]

I bought a KIM-1 SBC summer of 1979 and my Princeton graduated Physics grad student flatmate took it in and programmed it to play Yankee Doodle Dandy. I didn't get much out of it myself. But I managed to crack the RM/COBOL compiler to handle 8-bit characters for double-byte Asian characters processing somewhere down the line and more...

[@MarkHougaard]

Very cool to see. I've had my KIM-1 hanging on display in my home office for a while now. The 6502 is from 2776, the 6530 2276, and other 6530 1776 is in a white package. The only other differences from yours is there is a piece of red acrylic covering the LED's and someone added what could possibly be a power LED indicator over near the lower 6530. Somewhere in basement is rest of the card cage, nowhere as complete or well done as yours. I had picked the lot up from my former mentor along with his Apple ][+ system when he left Bell Labs to head west in the early '80's.

[@gumbykevbo]

Hi Dave. Broght back memories of the intel SDK-85s We used in college…different processor but All the same functionality. Yes your crystal is going to take the square(ish) wave from the clock inverter output and filter it to near perfect sinusoid, phase shift it by 180 degrees, and that becomes the input back to said inverter. Oscillators are fundamentally analog circuits, even though most are built using a logic gate as the amplifier. One hardware guy tip is to never trust that your oscillator is working or not working based ONLY on what you see on a ‘scope. The 10pF of a scope probe can be the difference between an oscillator that works or not.

[@angelogmassolin5056]

I had one of those- KIM 1- back in the 70's it was more fore learning ... i did build my own power supply and I was able to get a TTY if I/O with using paper tape and finally add a plane cassette tape player ... then life got in the way ... lol .... I'm in my mid 70's now and ave forgetten soo much from back then .... brings back so many memories ... 😄😄😄😄

[@Trygon]

Wow wow wow wow wow wow. Thank god you're documenting this stuff for a new generation. I only understand the shallowest surface layer of this, but it's still incredibly illuminating to lay eyes on it all.

[@turdwarbler]

This was great video and provoked lots of memories. I was at university studying computer science 76-80. In my 2nd year I used a Motorola D2 Evaluation kit II, very similar to what you have but the CPU was a 6800. All code entered in Hex and with a N digit hex display. I connected 2 kits together using 4 x RS232 lines set to different speeds and then ran messages across them. My lecturer (a proper hardware engineer) built a paper tape reader interface so we could cross assemble programs are read them in using the reader. It was all very cool in the heady days of 1978

[@garethfairclough8715]

So nice, I liked it thrice!

[@trevorockwell8764]

I love retro computers. There is nothing like having to program a vintage computer to see how much abstraction we have these days to code these complexities from us.

[@philarmishaw3730]

I got my start with a clone of the Apple ][ which was also 6502 based. I remember driving to Toronto to buy the bare circuit board and roms from seedy stores in back alleys. My biggest thrill was the day I fixed my last cold solder joint and it booted to life and beeped. Then the fun of getting an old surplus keyboard modified to work with the board. Lots of great memories that you have brought back for me. Thanks Dave!

[@jandomke5034]

What are you talking about, of course we´d love to see more of these ancient machines up and running and everything that comes with it!!! Keep up the great work. You´ve got to be my favorite tech channel! Cheers from Germany!

[@byronwatkins2565]

We use those in college to study 6502 machine language back in '83 or so. It was connected to a paper tape machine for storing programs. Apple II, Apple II+, and Apple IIe were also 6502.

[@eugenezenzen]

Dave, this is terrific! Really well done! Thanks so much, I'm looking forward to the next installment.

[@noelj62]

Vintage hardware, lovely.

[@evoelias6035]

Another great video Dave! I’ve never saw a real KIM-1 in action before. It is quite an impressive piece of history what you’ve bought. Thanks for the video, I have enjoyed it a lot ! 👍

[@johncloar1692]

Thanks Dave keep them coming.

[@ukcroupier]

Love this stuff, most retro channels just do C64, Spectrum etc so it's nice to see someone with the ability to get his hands on the serious gear. Also nice to see how far Visual Studio has come lol

[@kelvington4182]

This video is like going back in time for real. Great stuff!

[@kattphloxworthych]

Wow, the memories. I'm old enough to remember these. While he was in the USAF, my dad brought home two different computers that were compatible with the KIM-1, a Synertek SYM-1 and the Rockwell AIM-65. The latter was much more usable than either the KIM-1 or the SYM-1 as it was a complete system, including a keyboard, alphanumeric LED panel and a thermal printer. It had another thing that was commonplace among many computers of the day, Microsoft BASIC. I had loads of fun with the AIM-65 back in the day.

[@GlennHamblin]

Very cool Dave! Thanks for sharing.

[@juanmacias5922]

Such a cool video! Looking forward to this series!

[@basicforge]

Thanks for the video. I hope you make more of these and we get to see the entire hombrew system in action!

[@MikelNaUsaCom]

enjoyed it. this seems like a treasure chest of knowledge. not just the actual documentation, but the abstraction of that data out to learn the thought patterns of the designers, and the similarities and differences from other designs and even newer processors and busses. instruction sets and the trade-off with the choices for the hard and software... fun times. I really like how computers and most other products from that time period had great manuals. thanks for sharing! =D

[@wp5355]

Always enjoy this information - as I was originally a H/W guy and then loaded programs on a TRS-80 I bought new years ago. I wish I still had it, but I sold it years ago. Keep up the great work you are doing. I enjoy all of your presentations and try to follow as best I can on the software.

[@Chris-on5bt]

Please do more videos like this, I have been getting interested in early digital computers and I find these interesting.

[@RicardoPenders]

I'm for sure enjoying this video, looking forward to the next video about this KIM-1 computer.

[@insanelydigitalvids]

Really enjoyed this video, Dave. Thanks!

[@ejharrop1416]

Love it and look forward to the next installment. Thank you

[@sncln]

Dave - I enjoy all your videos. That said, there’s something especially exciting about resurrecting hardware. I really enjoyed this one and look forward to more. Please keep ‘em coming!

[@sameroomgaming]

This was before even my time. I'm so glad you tackled this one. Can't wait to see more.

[@loupasternak]

it was before a lot of peoples time, this is 2022 lol

[@howardwilliams2587]

Love it. I had my first Cromemco Z-1 around that time 1976. I was a little older than 8 at the time ...

[@Fingers1234567890]

Great video and amazing find, Dave! MTU was based in Greensboro NC - Hal Chamberlin was their main engineer - super talented group! I had a complete MTU computer system w/8-inch floppies running their own Disk OS. Sadly, I don't have it anymore, although I still have the floppies FWIW. A Kim-1 was my 2nd "personal" computer (after obtaining a used Mark-8!) back in '76. Loved it! I also had the expansion cage with video and memory expansion. Good luck and have fun!!

[@kylesheath]

Fascinating. My dad repaired TV and Videos in the 70 and 80s. Similar boards and I remember seeing him with his oscilloscope

[@dreamvisionary]

I love watching videos of this old computer stuff.

[@andrewbrady8564]

Thanks so much Dave! Reminds me that sometimes you just need to slow down and your patience will be rewarded.

[@BrianOrange]

Fantastic. Thanks Dave.

[@nukejunkie2207]

Loved it! Please continue on and get the rest of the boards working.

[@katiedonovanAlt]

Oh, MAN! This is even before my own time! I would have loved this back in the day!

[@neeosstuff7540]

Very cool. I started my computer education on the Apple II+ which is 6502 based. And started my career doing 6502 assembly language programming on an embedded ship board monitoring system. So I love seeing anything 6502. Thanks for sharing Dave!

[@osgrov]

What a great find, congrats! I'd love to see you get the full cage up and working. I've never seen any of that card cage stuff, that's really cool and intriguing. Please keep us posted!

[@mrt1r]

Awesome video Dave! I can't wait to see the rest of the computer up and running.

[@Marcel1984nl]

I just want to say what other comments are hesitant to say, what a nice looking and spacious house you have ;) Greetings from a fan of Microsoft. Keep up the good work!

[@pjfallon3]

I enjoy this content, I am in awe at the beginnings of microprocessors. Keep up the good work sir, thank you for the video!

[@ka9dgx]

That indeed is the crystal with 2 leads. The thing is actually a filter that allows only a sine wave at the desired frequency to pass, so the square wave gets filtered down to a sine wave, which then gets amplified to the square wave, and the whole thing then is locked into the frequency that the crystal passes. Sometimes way back then, things didn't always reliably start, and work had to be done to get enough of a thump into the system to get it to start. Your system doesn't seem to have that issue. 8) I'm helping a friend get an IMSAI going, and have learned to hate toggle switch inputs with a passion... you're so much ahead of the curve with the Hex pad. Good luck in your ongoing efforts.

[@InternetKindness]

Glad I found this channel! A lot of nostalgia for me. I wish I still had my old computers from when they didn't even come with unwanted preinstalled "apps" and annoying notifications, and just did the things you wanted them to do, usually! Learning programming myself as a kid is what got me excited about computers.

[@MrGul]

Definitely liked this and would love to see more like it! eBay retro finds are almost always entertaining.

[@KurtisRader]

I was a college freshman in 1979 at Oregon State University. My first microcomputer programming course used something like the KIM-1; at least in as much as it was a Motorola 6502 based system with similar capabilities. At the start of the course we used toggle switches, like you would find on an Altair 8800, to enter machine code. Thank dog those days are long gone. It was somewhat surreal given that the university also had a CDC Cyber 7600 which is what I programmed as a member of the "Educational Computing Service" department.

[@derekhawley9660]

Only understood

[@BustaHymen]

"For vintage hardware, you need to have the original Windows for workgrups screwdriver" :D And the Also sprach Zarathustra 2001 theme when removing the card... I enjoy all of your videos, but this one sure made me crack up

[@zh84]

I enjoyed it very much and would like to see you work your way through the rest of the equipment.

[@Rob_III]

@10:35 I always thought it's a "bodge wire". A quick round of Googling seems to confirm that.

[@MikelNaUsaCom]

short o is how I've always pronounced it... aw.. as in on... not o ... as in known. so bawdge wire =D

[@klightspeed]

9:20 The 6502 has its own crystal oscillator circuit, which drives the crystal resonator. The square wave on one leg of the crystal resonator would be from phi1(out) / pin 3 on the 6502, and the sine wave would be the natural resonance output from the crystal going into phi0(in). 10:35 Bodge wire - a wire to fix a design defect in the board without the expense of manufacturing another board run.

[@rjmunt]

Such beautiful documentation

[@martymcpeak4748]

That was a really cool video Dave. Thanks for doing these.

[@DavesGarage]

Glad you enjoyed it

[@RocketManRC-Electronics]

What a great video Dave! I started with the KIM-1 too and expanded it with a DIY interface to a S-100 backplane. I used it to control a home made analog music synthesizer and I'm going to speculate that it might have been one of the first synths ever controlled by a home computer :-) I actually still have both the computer and the synth although I haven't touched them for at least 40 years! You have inspired me to get them out of the box and make them work again.

[@mikemartinell]

Really interesting. Love to see this old stuff.

[@55ATA3]

Old computers were a lot of fun, the new ones are about keeping it as simple for the user as it can get.....

[@packratswhatif.3990]

Ahhh, sweeeet memories for sure. Very nice Dave ..

[@HighlandSteam]

Love it.. used a KIM1 at school when they were new!

[@andydraw4707]

This machine is on my wish list. Dave, please keep the videos on this beauty coming, I'd love to see it fully operational.

[@NaClSandwich]

Dave this is awesome! I cant wait to see all the trials and tribulations of getting this thing back in good order!

[@peteradshead2383]

I had a Sinclair Research mk14, which looking at the wiki was from 1977 which I can remember being at school at the time so sounds about right. also had a Sinclair black watch which I built in 1975 from a kit

[@Soren_Marodoren]

Ohh, yes. I love this. More pleace! Thanks in advance.

[@IlBiggo]

What a find! I didn't even know the KIM came with that many manuals. All I had was the 6502 instructions set and an instruction leaflet written by my colleague (he was the smart one) :D I spent a few nights coding with pencil and paper, then punching hex code into the machine. I had no idea that there were any expansions. We just had a homebrewed tape interface.

[@surferdude4487]

Can we just stop and appreciate that electronics that old still function? That was pretty cool.

[@glasser2819]

the true "solid state" electronics built after vacuum tubes was really bullet proof 👍

[@slowtony2]

Yes! Awesome video, beautiful machine, wonderful set of documentation. What usually dies on old hardware are the capacitors. The ones on this system looked pretty good. Maybe those early US-built parts were influenced by a 'Mil-Spec' last-for-years attitude. Later production parts in the small computer mass production era began to go down in quality as price became more of an issue. I know we had an IBM 3725 mainframe communications controller with a 3726 expansion cabinet that my company bought near its introduction in 1972. It was still going strong in about 2006, 34 years later. It was still booting off its 8 inch floppy disk. The old IBM stuff never died. We finally replaced our last SNA network lines with routed TCP/IP circuits off a big Cisco 7513 router. The much-loved always-reliable 3725 went off to IBM heaven. Bless Dave (and the original owner) for loving and saving this KIM-1.

[@animeloveer97]

less stuff to go wrong and built by hand makes a big part of its durability

[@glasser2819]

@@animeloveer97 lately most profitable designs include carefully integrated failure points to shorten repeat business cycles. 🤪

[@davep9565]

Great video, happy to see more of these. I have a bunch of early eighties computers (IBM PC and pre) which are going to need some TLC when I get the time so the diagnostics is as interesting as the nostalgia.

[@KeyserTheRedBeard]

exceptional content Dave's Garage. I shattered the thumbs up on your video. Keep on up the terrific work.

[@PatrickRosenbalm]

Good Stuff Dave!!! Like some other posters, I learned assembly on a 6502. On an Atari 800 to be exact. A must if you wanted speed. My biggest project was writing code to scan a music keyboard and play notes. Not going to get into that here but might on my channel in the future. The 6502 was also used in some Ohio Scientific computers and a computer I used in college called a Micro Five from the UK. I think that was its name.

[@danman32]

I loved my Atari 800! Found the full tech manual for $25 back then. Wrote a bootloader program that let me put letter perfect, data perfect and mailmerge all on one disk.

[@PatrickRosenbalm]

@@danman32 Love it!! I still have mine but the PS and other peripherals got lost in a move 20+ years ago.

[@Sticks210]

Very much looking forward to more videos on this