Humble Beginnings: The Ohio Scientific Instruments (OSI) 300 Single Board Computer
Вставка
- Опубліковано 29 тра 2020
- #vintagecomputer #6502 #sbc In 1975 a husband and wife team started a company called Ohio Scientific Instruments to produce electronic training aids for students. One of those devices was the Ohio Scientific 300 single board computer, among the first computers ever to use a MOS 6502.
This video.will present a bit of the history of OSI, demonstrate the use of the computer and provide some information of use to collectors. - Наука та технологія
Why do this channel doesn't get more views? The video was great, keep up good work :D
Many thanks!
I’m glad I subscribed :)
The channel isn't even a year old; give it time.
Oh! So that's where this video went. I was worried it was gone forever.
I majorly dig the OSI-300, and it inspired a project or two of mine. Thank you for showing this machine the respect it deserves, and exposing new users to where it fits into history.
Yeah I sort of own-goaled my old channel. Accidentally deleted it while trying to switch to a so called branding account. Doh! :)
Having worked for an OSI reseller back in 1980/81, I remember making many a phone call to Rick Whitesel for technical support. Rick was a savvy engineer and OSI was lucky to have him.
OSI is such an interesting company. I'm still a bit confused how the post-acquisition played out.. there is a mess of company names after 1981 offering OSI hardware.
I remember Rick! I worked for OSI in the early 80s! Great guy.
Wow! This makes the Cosmac Elf look like a workstation! I didn't realize such a simple 6502 machine could be constructed.
With modern parts (you can still get brand new 65C02s) you can build something with three chips, a static ram chip, a flash rom chip and the 6502.
Man this stuff is so cool! Thanks for going as in depth as you did - as someone who's only watched videos on stuff like basic and assembly and never tried them myself, it helped to have the diagrams and explanations :D
You should watch videos on adrenochrome
In one of my very early microprocessor adventures, I had interfaced an Intel 2851A to my MMD-1 8080 trainer and to an "ADDS" terminal (circa 1981). When I was finally able to correctly initialize the 8251 and write a utility that filled the terminal with the letter "A", I was elated! It doesn't seem like much, but it opens the door to a plethora of possibilities! :-)
I still have two OSI computers, a Challenger 1P and a huge 8P with their terrible molex connector bus. I actually used my C1P as a terminal in the late 80s while I was going to college. It worked well because I did the mod that gave it 64 characters per line. I wrote my own terminal program in assembly and wrote a Unix termcap that worked perfectly with it. I learned a lot about computers because with OSI computers, you pretty much had to.
Everything in it was the cheapest possible way to implement anything. The keyboard didn't use a PIA. It just used a couple of addressed 8 bit latches. OSI didn't use expensive floppy controller chips. They used a PIA to control the drive and a serial chip (a 6850) to read and write the data. Yes, floppy controller was much like an RS-232 port.
I have the OSI 300, 500 Superboard II, the C1P, C2-4P, C2-8P, C4-4P, and an empty C8 case. I'm a little OSI crazy. What got me interested initially was the little game characters they included in their character ROM. They just have such a homebrew kinda feel to them.
@@TechTimeTraveller Aren't they much like the characters the ROM in the PET had? In fact a lot of the Superboard II/C1P is much like the PET.
It's hard to believe that the cassette interface was just like the punch tape on a teletype. You typed "LIST", set the cassette to record, then hit Enter and it "typed" your program to the cassette. To load your BASIC program, you had the cassette "type" the program back in. I don't know of any personal computer that had such a cheap method of saving and loading programs.
@Scott Larson Yes very similar in principle to PETSCII. I don't think PETSCII had a Starship Enterprise though.. that was the one that got me.
And yeah the OSI save and load process is.. different. I guess it's one of those things that gives OSI its charm or personality.
I had a rack mounted OSI computer with z80, 6502 and 6800 all on the same mother board. It had a 74 MB hard drive (winchester) rack mounted along with dual 8 inch floppy drives. At the time it was the best affordable commercial system for my company I could find at a 'reasonable cost'.
It's too bad OSI was so stuck on not finding venture capital to expand. They hit a certain level and then just didn't have the money to go further.
OSI also tried a similar board that substituted a Harris HD6120 chip for the 6800. Yes, that made it a PDP-8 computer. The 6502 did all of the I/O for the HD6120 through DMA so it was (supposedly) able to run any OS or software ever written for the PDP-8. I saw the schematics and the description but I don't know if it ever made it into production.
Sounds like fun 😀
My first micro was a Superboard II. Taught myself 6502 machine language and assembler on it. Fond memories. You never forget your first one.
You can 3D print covers for the switches. Seriously look into it. I would love to see more projects using it.
Music is a little loud but as usual fantastic production sir, and thank you for not just hiding your collection away in storage forever but instead showing, talking, and demonstrating them for us to see. I'm sure there's many machines lost to time due to stingy owners.
Many thanks. This was the first 'at length' video I ever did, on my old channel before I reloaded as TTT. And yeah.. it uh.. has some rookie stuff going on. :)
I was an engineering studen in Ohio in the late 70s/early 80s, so OSI products were very popular. I miss the diversity of the early days of the personal computer revolution.
Come for the mini scribe, stay for the amazing history on true computer tech!
Speaking of Unobtanium computer devices, I have two Electronic Systems 106 TV Typewriters which I picked up at a local surplus house about 20 years ago. After watching your videos on the CT-1024, I dug them out and attempted to get them working. I now have one fully operational but what a mess! Cut traces, missing chips, bad sockets and even one chip with a pin folded under. It works as designed but is very crude. The second one sort of works but it is displaying two pages so I need to spend more countless hours sorting it out. I have a GRI 756 keyboard to use with them that I bought as a kit around 1976 or so, basic keyboard. No keys like backspace, cursor up-down-left right but there is provision on the 106 for push buttons for these functions. I will probably post a video soon showing them. Thanks for sharing all these vintage computing devices. I teach Windows and Linux at the local community college and most of my students weren't even born when we were using these devices!
I love this. A blast from the past!
Ok I learned that song as "Pea porridge hot, pea porridge cold..." way back in the 70s, never heard of this pudding version until now.
I thought it was Peach porridge.
This is amazing
You regularly comment about your age, then I discovered you're younger than I am. /me goes and cries...
Really educational! Thank you
Loved my Superboard II back in the day.
I have one in a Challenger case here. I should drag it out sometime. I love the graphics characters, like the USS Enterprise and stuff that they had there.
good show chap......found you ....now hooked
Contact cleaner / lube on the switch contacts and slides? Also, perhaps mount it on a wooden board with pegs around the corners so that you can get leverage without pressing on the switch frames? Though, perhaps that will put too much strain on the switches' attachments to the board? Nevertheless, old slide switches need lubrication IMO. Thanks so much for the demo. I remember seeing ads for these as a young teen. I never saw one in use.
Speaking of "trainer" computers. It's not exactly electronic, but you should consider doing a video on the CARDIAC "computer." Which was basically a bunch of cards and folders and pull tabs that somehow copied the function of a computer without any actual electronics back in I think the mid to late 60's. But don't quote me on that. I always thought it would make a good video for a channel like this that looks at the history of computer and computer related gear.
Wonderful, I live in Aurora/Hiram area but never heard of this
What a neat little trainer board! Seems like it should be programmed with heavy, leather gloves, though. 😬
Wow. I had one of those OSI-300 boards. Mine had a 4 or 5 bytes of RAM (out of the 128) that didn't work properly. "Just don't use those." Thanks for the memory.
Lol "just don't use those". Was that official OSI advice? It sounds like something they'd say.
@@TechTimeTraveller Nah. I bought the thing secondhand in ~1977, so I never bothered OSI about it. I just learned not to use those bad memory locations. Given the types of things the board was good for (not much other than simple demos), it was not a big deal. Just funny.
BTW, if you want that ASR-33 refurbised to like-new condition, I know the guy for that. Just got mine done.
This has me so incredibly excited, I've always wanted to gain this kind of fundamental understanding of how a computer works and I would be enthralled doing the exercises on a training computer like this! Does anyone know if something similar can be bought for a lower price or if something like it is made today? I love the idea of going address by address and programming by setting bits by hand, incredible! Thanks for uploading this video.
What is that jazz? It sounds wonderful and works perfectly with your video.
It's something I picked out of the youtube audio library. I find jazzy sort of music works best.. you can get to a volume where it's audible but doesn't compete with your narration.
That is awesome! It's about as bare metal as you possibly can get. I'm so tempted to build a modern take on this (although presumably would need a processor and ram that is fully static and doesn't mind having its clock stopped or run at really low frequencies).
That would be cool! A UA-camr named youtuuba built a modern replica and I was impressed at how small it was compared to the original. Seemed to work functionally the same. I'm not sure if the kit he built is still available but it looked like a fun build.
@@TechTimeTraveller , I am "youtuuba", and that "OSI 300 Mini" kit I built was produced in small quantity years ago by a fellow in the Chicago area. He seems to have lost interest in it long ago, so I am glad I bought mine when I ran into him at one of the Vintage Computer Festival Midwest events. I recall he was selling the kit in little zip-loc sandwich bags for $20 each, all parts and PCB included.
That OSI 300 Mini is the same exact circuit as the original OSI 300, except a large static RAM IC was used because the very small capacity originals are hard to obtain, expensive and unreliable. Because the RAM was larger, the kit had more address switches and LEDs to take advantage of it.
I thought about making my own version of this and selling kits on eBay, but I recall the other guy said the sticking point was the extreme difficulty in obtaining one of the slide switches that had a special combination of make-before-break and break-before-make contacts that are required by the original circuit. If I were to do it, I would want to opt for modifying the circuit to use an easier to obtain switch, but then other people would probably consider the design to be unoriginal and tainted, and not buy the kits. I still contemplate doing it from time to time.....
I just converted my superboard ii into a “laptop”. I posted a thread with some pics in the OSI forum titled “OSI Portable Project” if you are interested in seeing how it turned out and some more info on it :) I’ll make a video soon.
Definitely going to check that out! It's on osiweb.org ?
Aurora Ohio is just west of Hiram, OH. Both are pretty far south of Cleveland.
I wonder if you could make a big board of 100s of pin jumpers and use that to write code and then have some sort of circuit to automatically feed that in line at a time.
Hook up some test probes to the inputs and bitbang a program into the memory at a fast rate, that is how smart people would do this. ;)
OMG This is exactly what I need. Someone please tell me there's a modern equivalent that uses the 6502...
I made something very similar on my channel! It's a very basic simple computer and I 3D printed the case in wood filament. You might enjoy it! Great video btw
Out of all the vintage machines I've seen, I think this one would be the easiest to make a reproduction of. ;)
I would love to build one of these. It seems like it would be fun but simple enough to design as there are so few components!
@@michaelcobb1024 the problem with this design is that it used a custom slide switch for one of the functions, which had a now-unobtainium combination of make-before-break and break-before-make contacts. If not for THAT, it would be easy to replicate.
@@youtuuba needs a toggle switch upgrade ;)
Start = $007C... YAY FOR PARTIAL ADDRESS BUS DECODING! ;)
tempting to build a clone just for kicks. Wonder if I can make it use a Z80 instead of a 6502.
There was a kit at one point: ua-cam.com/video/OTmFDruVQrY/v-deo.html
@@TechTimeTraveller After watching your video I found a Schematic, Could probably spend a day on Eagle Cad and create a PCB or pull out my Wire Wrapping equipment and Wire Wrap a Board.
@Stephen Anthony I was never a fan of the 6502.
@Stephen Anthony It's all in good fun, it's not like I plan to key in the machine code to run DOOM or anything like that.
@@lelandclayton5462 😢
I can't believe they thought the correct first character to print was A.
Should have been [Bel].
19:42 - What color does it compute? :)
afair the 6502's stack is at adress 0100h - 01ffh, with the OSI-300 having just 128, does that mean there is no JSRs possible? or was there a way to move the stack somehow?
Edit: ok, since that RAM chip's chip-select may be hardwired, the 128bytes memory most probably are shadowed to ALL addresses within the complete 64k address space, (just like that reset vector also was in address 007xh (instead of FFFxh where it should be), so even with that 128b RAM the stack should be usable. Forget that question :)
Thanks for the video! It might go easier on your fingers next time if you wrapped the switch edges in electrical tape.
Sometimes you gotta suffer for art. :)
Why not put the Band-Aids on first and avoid the wounds?
Was sort of a 'experience first, lesson later situation.
First use of a 6502? Call me interested.
I guess most of these boards would have originally been bought by educational institutions and businesses, and probably scrapped by now. If any were bought by individuals, some probably would have ended up being scavenged for parts. So they probably are a bit rare these days.
Primitive, but charming anyway!
Why didn't you modify the board or made a copy instead?
You mean to fix the switch problem? When it comes to vintage originals I tend to adopt a hands off approach unless it's absolutely necessary (ie something broken). This isn't the sort of thing you'd be using every day anyway so I was fine to suffer through the switches.
I would'nt want to write a game on it. It would take an forever with those switches. LOL.
My fingers would be sliced right off. :)
@@TechTimeTraveller Ha ha.
Can it play Crysis?
It might be able to spell the word on a teletype... :)
this shouldn't be too hard to reproduce.
Do you really need to put that loud music? It makes it hard to understand; not everyone has English for his first language or has perfect hearing.
I apologize.. it was the first attempt at a documentary style video I'd ever done.. had to learn a lot the hard way.
@@TechTimeTraveller ■ Oh ok. Sorry if I sounded harsh.
I’ve been looking at a lot of your videos, as I have seen or worked many of the systems you show, back in the day.
My first computer ever was a hand-made wire-wrapped SWTPC S-09 running Uniflex…
@@emdxemdx Oh no worries. I wish UA-cam allowed substitutions but.. cest la vie. Wirewrapped??? As in no kit PCBs? You just worked off the schematic? That's pretty bold! I don't have a 6809.. just their 6800 and a few of their terminals. But yeah, major respect if you hand built one of those.