An ELF *off* the shelf | The Quest Super ELF | COSMAC 1802 

Another step on the road to the full COSMAC ELF documentary! I really want to build out the expansion unit on this thing! And maybe take some music lessons (25:52).

My physics teacher at school built an ELF from the magazine article... it ended up with me having a career in computing.

You know it was owned by a ham radio operator when you find a PL259 connector on the video cable. 😂

Hello! I’m the person who sold you the Super ELF. I’m glad that you’re sharing this adventure. It’s really cool to see it working. The machine was in a complete enclosure when I received it. It was in display in my office for a while and I didn’t want to see it go. Thank you for sharing this.

Goodness, I soooooo wanted one of these as a budding (teen) computer engineer. Love the 1802 architecture 😊💜 Fun fact: A COSMAC 1802 flies in the Hubble Space Telescope. The 1802 is one of the few μP that was radiation hardened such that it could survive spaceflight.

31:56 Ok… That’s funny… I was the person over at the Cosmac ELF Group how gave you the two byte program for quickly testing the video. Op codes 61 69. Super nice looking Super ELF you have. I’ve resurrected several. I’ve got one that is expanded with a modern 1802-mini bus with 64K RAM, 32K Firmware ROM, Compact Flash Hard Drive for ELF/OS, TMS 9118 graphics card, real time clock and UART. I have another that is all stock with the Quest Super Expansion board. These things are bulletproof. I also agree about the key switches and bouncing on the ELF II. I had an ELF II when I was 15 and the Quest keypad is just better. The circuit board will be marked at the lower end with the date (1977) and the revision. Mine are Rev 4 units which are the last ones I think.

It always amazes me how expensive the early computers were, adjusted for inflation, the cost would be about $440 usd.

Always a happy day when a new long-form TTT vid drops...

Boy, I remember that Popular Electronics in the summer of 1976 which also began a series of articles about programming the 1802. I was learning about electronics and I knew nothing about digital electronics or microprocessors so this was my first introduction to this strange form of electronics that's all ones and zeros and was mostly running wires between IC pins. The articles also taught how to program the 1802 when all I knew was BASIC. I remember being exciting about discovering how a computer really worked. I wrote lots of small programs in 1802 assembly and executed them in my head to see if they would work. I'm glad I waited a year or two to buy a real computer with a video display.

That small card w the 7 segment displays looks like a Cosmac VIP card.

Love it. Bought a kit when I was 13 from Neutronics and recall reading the book from Tom Pittman. Oh the memories. Thanks for sharing.

Fascinating to learn about so thank you so much for sharing! :)

I remember that issue of Popular Electronics. I so wanted to build a Cosmic ELF. There were others that also came along. We ended up getting a Heathkit H8 that my dad and I built. Nice it had a monitor program and an 8-digit display with a 4x4 keypad (offset octal). I remember entering programs via the keypad; especially the memory test as the ram chips were unreliable. Soon upgraded with floppy drives and CP/M. Would love to get it going again but the disks are unobtanium as they were obsolete by the '80s (hard-sectored floppies).

That CDP1861 working is a miracle ✨✨ I enjoyed the video on Elf in working condition as i have never seen one except in popular electronics Thanks !!

I uesd to (WAYYYYY back when) go to the library and look at the computer magazines from the late 70's early 80's. They had schematics, PC board layouts and code. I always wanted to build something like this.

Tandy sold one of these DIY computers with a heavy metal case. The program you finally entered was exactly the one they used to test the system. I built mine in 1973 or 1974.

I had a COSMAC ELF kit when I was 15, but I was never able to get it working properly. My soldering skills have never really been that good. My failure to debug and fix the problem was a direct contributor to my decision to become a computer programmer instead of sticking with electronics. I am extremely happy with that decision, I've had a great life as a computer programmer! "Glück im unglück!"

That video connector PL259 is far superior to any RCA connector ever made❗️

Wow, that's amazing that it can be played like a musical keyboard!

This may have been mentioned already, but that video connector isn't broken - the tip is cut like that to make soldering easier. If memory serves, that's a PL-239 connector. i suspect the gray paint has the outer threaded part stuck in place. (you shove the pin to an SO-239 connector and the barrel threads on to that)

I'm very happy to see that this unit worked very well. Welcome to the 1802 community. Quite a small following still in love with this microprocessor. I have the super expansion unit. You'll need some more SRAM. You can find the 2102 SRAMs still on firms like Jameco. It will set you back around $100 before shipping to CN. You might be able to find a supplier in CN. The power supply requirements vary by the options you 'activate' on the expansion board. Good Luck and I'm looking forward to your next video.

I have my ELF hanging on the wall in a professionally built museum-quality display case. You can catch a glimpse of it in some of my RU-vid videos.

I know I'm old because I remember when each of those seven segment displays became available and I bought them all back in the day.

I still have that Super Elf that I bought as a kit when it was released. It has been sitting for years and years in the basement, until I dug it up a few months ago. It was in a pretty rough state, but still complete. The keyboard keys where extremely unreliable and the Tantalum caps where in a bad shape. So I completely revised the board and replaced the keys with newer ones (set in a matrix holder I 3D printed). I got the computer in full working condition again. My board has that ROM by the way. It's handy, but no more than that. There is only one thing I want to replace, and that's the FND500 7 segment display. They have becom very faint over the years. However - Replacing them will not be a easy task, because they are not produced anymore. Sadly so far alternatives turned out to be not working or very, very (almost invisible) dim. It's a common Cathode model, and those are not that "common" at all. It's difficult to find a replacement that has the same IF and luminosity. But - It's fully working, and I fired up some programs I written for that board years and years ago. Sadly I have no expansion boards or anything, so I have to make them myself. But that's a project for another day. By the way - That little loudspeaker was mounted with double sided tape in the space between the crystal and the video chip, so you did not need a case or anything.

I got an Elf II in ~76. That was all I could afford at that time. Then bought a serial keyboard and a RAM board with 4K and loaded TinyBASIC. It was damn slow being dual interpreted to fit in memory but the joy seing for the first time the "OK" prompt and typing small programs. I later got a SYM 6502 which was several times faster.

Ooh ahhh, a Quest Super Elf. That and the Netronics Elf were in Popular Electronics ads and I so wanted to buy one. The 1802's assembly is primitive compared to the 6502, but it was the first CMOS microprocessor. It also went to Jupiter, so that's an achievement.

I was 10 yrs old and drooled over the ELF. Too bad I was too young to figure out how to build one or even have the money to buy the kit.

Built the quest super-elf in the early 80’s. Added 4k expansion, tiny basic and an additional 8k memory card. Still have somewhere…

I love the tech that is so old that it goes completely over my head, Great video!

Good little machines. I've had the parts to build an elf for years and have never gotten around to it. Should you still have trouble with the PIXIE chip there are some schematics out there for building one out of discrete chips

Just subbd! Member of the groupsio and an old love affair with the cosmac vip. Thanks for sharing.

RCA did sell a version of the ELF as a kit called the COSMAC VIP.

Never heard of ELF! That's incredible. You'd think a bouncing ball program or something would've been a really cool (and much shorter) video demo though lol

This is an adorable machine, I quite like it! Even without the video subsystem. This is among the lines of something I would absolutely own as a modern day kit, since I'd feel bad taking a vintage example just to goof off with.

I've always wondered how many people flocked to the Elf after finding Altairs too expensive. I mean $400-600 was used car money back in the mid '70s. Anyway, the 1802 is my favorite processor in terms of its development history and design. Sure, it's probably the slowest microprocessor from the time but its low current design and multitude of built-in I/O pins made it appealing for budget enthusiasts and industrial development. Nice video!

rca-cosmac-in-a-swtpc-6800-case the industrial full sized dev eval version, I built two of these back in 1981, this one was auctioned off on that popular site recently. I worked in a UK electronics company that had a Zentel autotest system, that had a RCA PC which was 1802 based supposedly...

Congrats, I enjoy Your old stuff. I had a win, too: a Grundig RV55 with the Sennheiser KB55. The RV is a tube ac milivolt meter and the KB is to determine the distortion factor in tone generators, amplifiers- stuff like that. Both devices are proper survivors, no rust, no nothing. Just clean, shiney paint, pretty boards, no green stuff- pure joy for just 44€ incl. shipping. Ain´t gonna pass that! Do I need another meter? Shure not but them boxes are sooo pretty and the RV I looked out years for. The KB I owned for a long time, I wanted the meter. It´s proper lab stuff, Yay! Have a good one, I´m looking out for You playing Wagner`s Walkürenritt on it... ;)

dude your videos make me so happy. they're so well put together and just happy. the bob ross of electronics haha

I wish I was around for the kit days. I would have loved to of built many from those days. I learn with my hands so I could have gained more about how a computer worked that way than any book. Same with the radio world when you could build your own ham radios and stuff with plenty of kits to choose from.

My older brother had the ELF II. I made a tape player interface for him.

Yes, you can use S-100 static ram boards & video boards in the two S-100 connectors. DRAM boards do not work. I had a 4K (maybe it was 8K) ram board plus a SSM video board that I used with my Super Elf.

The tip of the PL259 wasn't damaged. It's shaped that way for soldering purposes to create a cup for solder to flow into. Good call on swapping to RCA though. That will be much more convenient.

Now you can make your own QR codes on this thing

I'm amazed that it just worked. 👍 Shame you can't save and load programs. I wonder if you could make an interface for an Arduino to simulate the key presses somehow, to emulate the keyboard, you could store programs that way. (I hate Arduinos, but they do have uses)

@CelGenStudios did a couple of videos on RCA 1802 based stuff, namely a homemade computer with a full keyboard and a dev system (minus keyboard, *grrr*).

Get yourself an automatic wire stripper because it's so much nicer to use.

LOL @ music skit

Excellent video. 2b or not 2b, that is the question. Excellent vid! The is the best look I've had on the Elf. I came along the following year when the TRS-80 came out. Nice job they did on the Pixie Chip. Does that mean the Super Elf has a text mode or do you build your text from those graphics?

I'm curious about the brown patch on the PCB - is that a burn mark? And what looks like a bunch of resistors mounted way up high ("flapping around in the breeze") above the board. Are these two things related, I wonder?

You need to extend your wedding ring

$80 in 1976 is $438.50 today

What's the song called that's playing during the soldering at around 21 minutes?

I'm amazed that it just worked. It's a shame you can't save and load programs. I wonder if you could set up an Arduino to simulate the keyboard. You could store software that way. (I hate Arduinos, but they do have uses)

Could this be upgraded to run the CHIP-8 games that originated on the COSMAC VIP? At glance, it seems so (just add more RAM) but not sure. Asking because Chippi+, a CHIP-8 emulator, was _just_ released for the Mattel Intellivision console.

Are you sure that you soldered the cable with the rca plug on it correctly to the board ? Are you sure you didn't hook it up backwards ?

19:17 Is that a PL259 connector?

All parts for an ELF are obtainable today, are they not?

I love RU-vid censoring comments. we might as well have not bothered going to school college or university, just slurp and durp and click what UT wants us to. hand them our CC details.

2b or not 2b? That is the question.

God 1970s micros were so terrible, unless they were made by Commodore, Atari or Apple. And I say this as a GenX child of the 1970s/80s. I salute your bravery sir!

What use is a platform that censors comments with technical details,