Demonstration of a Sphere microcomputer from 1975
Вставка
- Опубліковано 26 лют 2023
- Demonstration of the setup and built-in functions of a a Sphere computer from 1975. This was a modular, very early microcomputer from Salt Lake City. It was based on the Motorola 6800 microprocessor. In this video we look at the most basic configuration, just a CPU and CRT board, and we connect them up without the standard case, directly on the desk. Then we try out at Sphere's Program Development System (PDS) firmware, with its editor and mini-assembler. The Sphere computers were sometimes referred to collectively as the "Sphere 1" computer.
Watch my presentation at the Computer History Museum in 2022 about the history of Sphere computers, the company, and the community:
• Sphere 1: The First Mo...
Info on Sphere and this project, including documents, images and software information.
sphere.computer
(Sign up there for email updates on the book, etc!)
Sphere web emulator:
sphere.computer/emulator
Mike Willegal's PS/2 to ASCII Keyboard adapter:
www.willegal.net/appleii/apple...
Sphere user manual:
www.bitsavers.org/pdf/sphere/3...
Copyright (c) 2023 Ben Zotto.
Music (c) (p) Arcal Productions, used with permission.
Love it. In around 1977/8 my father brought home from work a Motorola 6800 evaluation board, hex keypad and an row of 7-segment outputs & s 6800 programmer quick reference card. I had hours of fun thinking of a program, write it on paper hand assemble (including working out relative branch codes! I actually knew that $FD was going to appear in your assembler example before you showed it. So just goes to show the brain today can still do what I did 45 years ago at the kitchen table.... Happy days.
Hopefully liking and commenting might make the UA-cam algorithm recommend this to viewers of other channels I follow.
Top video
Thank you Rob! Appreciate that
The way you setup the shot, with the wood grain table and the wood paneling, and the colour grading, makes this video look like a documentary made in 1975. Very well done!
I feel seen! Thanks Jeff, glad you enjoyed.
You have been seen. For sure. I was going to write the same comment.
Nailed the era perfectly.
Once I saw the logo and the text on the display, I remembered reading about this computer as a kid.
Have you seen the Fairchild Channel F game machine? The Fairchild was first and offered many features compared to the Atari VCS (2600), which ended up better.
This computer is the Fairchild and the Apple is more like the VCS, by analogy.
It is a nicer machine than I expected. 6800 CPU, built in mini-assembler / monitor, composite video out... thanks for the look at it.
Nice work. I can feel that 70's vibe from here.
@@bzotto so how did you do it?!
@@paulschilling2996 Movie magic! And a genuine love of 1970s aesthetics.
This Sphere computer seems very similar to the british Nascom-1 kit appeared 1977. The Nascom-1 was my first personal computer. It was based on the popular Z80 (1 MHz clock), had 1 KB RAM, 1 KB ROM, a character generator ROM, one PIO, and came with an ASCII keyboard attached. A composite video output and TV-modulator allowed to attach a TV-set as monitor. As software it came just with a monitor programm. A "Nas bus" allowed using some extension boards with RAM, graphics and several firmware and IO options.
I extended it later with some wirewrapped boards up to 48KB RAM, WD floppy disk controller, 2 8"- Shugart floppy drives and an old 5-but Baudot teletype ("Fernschreiber") as printer. So i could run CP/M 2.0 with all fine software like Turbo Pascal, Fig Forth, WordStar text processor etc.
My first industrial produced home computer was an Atari ST 520 with a 20 MB hard disk and very fine monochrome display.
quite the drastic jump from a computer without I/O besides text mode and a keyboard, to a computer with a 20M HD
i had a series of 8bit and 16bit computers before i got my first computer with a HD
Great video! Glad to see the UA-cam algorithm has blessed you.
Thanks! I love the algorithm now! :)
thanks for sharing an important part of computer history. my first contact with computers was 1984, since then I've been fond of computers from before the 80's.
I was born and live in Brazil. Between the 80's and 90's we had a period of market reserve, in which the Brazilian government prohibited the importation of technology equipment. So the national manufacturers copied the models From other countries and sold for exorbitant prices, All this without paying royalties to the developers.
I was a teenager at the time, children of parents with few financial resources, I walked to school and didn't have a snack to save money on the bus And lunch, so you can buy my first used computer that I found in newspaper classifieds.
Difficult times, but in such a way I learned to use computers, I became a programmer, and today I work with server virtualization.
At the time Sphere was released I was 5 years old
My first computer experience was in 1968. It was a specially built computer and the only one in existence. The language, back then, was Fortran and Cobol but we had to devise our own language. This machine was constructed by a government agency that, officially, did not exist. It had a monitor and a keyboard but no mouse. I also saw a home-built Faraday cage with 1.5X .25 inches of wood strips holding together a copper wire mesh. This cage housed a printer. The project was experimental and did not achieve anything positive. At least, that's what I was told.
Love it when UA-cam shows me a really small channel. Awesome video, can't believe it's got so few views! Keep it up!!
Hey, thanks Alice! I'm not much of a channel but I am glad you found and enjoyed this and there are more Sphere related bits to come!
I had the same thing; clearly UA-cam really wanted me to watch because it's recommended it to me about 4 times now and I only just caved
@@bzotto But for a small channel you've put together something of impressive production quality. I love computer archeology and it's hard to imagine today how much work it once took to get the simplest of systems to market.
@@menacegallagher7334 😂
When I was a boy here in the 70s in Brazil the electronics magazines brought tiny ads of Sphere: "a real computer" and I was amazed, but it costed so much. I always wanted one.
Thx for the video. I saw an ad form the 70's with the Sphere 1 kit selling for $860 😎
Awesome demo! Ever since I ran across a Sol 20, I've been dying to learn more about the Sphere.
Glad you enjoyed it! The Sol was very important and Lee Felsenstein's memory mapped video tech (VDM-1 and then Sol) was a contemporary of (and frankly better than) the Sphere tech. I've spent a year+ neck deep in book research so there'll be more to come.
@@bzotto Awesome, can't wait to see!
This is fascinating; I had never heard of Sphere, and had no idea it was so early. When this machine premiered, Lee Felsenstein was still trying to realize his "Tom Swift Terminal" vision by merging something like the Altair with Don Lancaster's TVT ideas into a full-up computer. He wouldn't succeed until the Sol-20 in 1976. (Worth noting that he was aiming at a machine that could specifically out put to a TV.) It's interesting to note that, as far as I can tell, Levy's "Hackers" doesn't even mention Sphere. Nice work on this research.
Thanks Joe, glad you enjoyed this. Yes, the Sphere was very early, although truly that was a remarkably fertile period where lots of ideas were emerging week over week and often simultaneously. Sphere was based in Salt Lake City, culturally very far from northern California where a lot of the homebrew culture was centered, and I think for that reason it tends not to feature in the "Silicon Valley" histories-- there just wasn't really any overlap in people, or ultimately, users. The Sphere machines were ultimately sort of unloved (frankly for justifiable reasons) and there weren't all *that* many of them made before the company vanished so it's understandably rather obscure today. I'm writing a book about it because I think it has more historic interest than it's been given.
There is another interesting system from this era, called “ZGRASS”. It was a BASIC dialect unlike any other, with a kind of GUI, built-in threading (just a foreground and background thread), and no line numbers. Instead, you defined functions by storing their bodies in string variables, which you invoked via an “eval” function.
This was all implemented on a Z80 in 1976.
my exact same thoughts
looks very intriguing
Tada lmao, love it keep up the important work to preserve our history !❤️❤️❤️
I remember back when you bought electronic devices such as guitar amp
...a full schematic was included, wish they would still do that today
And how many manuals these days include a section titled "Theory of Operation"?
I remember reading mentions about the Sphere in "Fire In The Valley". Pretty awesome to see the real thing.
It's killing me that I missed those two boards that were just on ebay (although the CPU board had some damage). Thanks for this!
I'm certain more will appear. These systems were ultimately just not *that* scarce-- even though they were sort of unloved. Glad you enjoyed this!
Fancy seeing you here! Small world.
@@bzotto Do you have production numbers in your archive? I had always thought they had only produced a few hundred or less and then collapsed. But I've seen photos of the production line you had somewhere and I'm guessing they must have made a decent number over 3-4 years. Problem is if a number are just boards who knows how many have been tossed over the years.
Wow, this is very clearly demonstrated and narrated. Thanks!
My first computer experience was with a IMSAI 8080. This Sphere would have been much easier for me back in those days. Glad you have this system up and running 😀
Thanks for the video. I have never heard about this early system which is a remarkably advanced concept in comparison to other system of the late seventies. I am looking forward to more videos.👍
Hard to believe a computer like this is almost 50 years old.
Epic video. Thank you for the education.
what an interesting little computer. Bonus content was seeing them stamps from my country :)
I have been a computer nerd since the early 80's when I got my Atari 800. I LOVE coming across videos of computers from that time I had never heard of so thank you sir.
The Sphere is nothing if not incredibly obscure! But historically significant, so I'm glad you found it interesting.
@@bzotto I always wonder why Motorola didn't make clones of Intel processors like AMD and Cyrix did.
9:16 0xFD as a signed 1-byte integer is -3. At this point the PC will be pointing at 0x0403, so subtracting 3 from that will put you back at 0x0400.
My dad was one of the original employees of Sphere Corp. Mike Wise was always a good friend of my dad and even attended my wedding. Sphere even had motorhome that they used to travel to computer shows all over the west.
John: Thank you for leaving this comment. I'm the guy from the video here and believe I've spoken recently with your sister. If you have recollections about Mike, or the company as your dad was involved I'd be happy to hear of them for the book I'm writing. You can reach me at bzotto@gmail.com, and she also has my info. Thanks!
The Commodore PET was most surely inspired by this computer. It borrows the same TV-Typewriter full screen editor and the sheet metal all-in-one case. A 6502 Sphere version wouldn’t be too hard to make
The Sphere may have been the first fully self-contained _computer_ which was designed this way, but data terminals (to connect to mainframes, etc) with a CRT, keyboard, and all-in-one case had existed for quite some time before this. The IBM 2260 video display terminal, for example, looked very similar, and was first released over 10 years earlier in 1964 (before ICs even existed!).
So it's quite possible that the PET was simply emulating earlier data terminals (as I'm sure the Sphere was), and may not have actually been directly inspired by the Sphere at all (but it also could have been, you never know).
Very interesting feature. Found you via Hackaday recently and had done a search for early 6800-based computers about a week prior. Neat history you've documented. Thank you.
Glad you enjoyed and it was timely for you!
What an interesting computer! It reminded me of the two differences between machine code and assembly. Either one, it seems, is optional. The first is mnemonics. The other is labels and linking. The latter is far more important. You can get by without mnemonics. You can get used to writing and reading '01' instead of 'NOP'. But without labels you may have to change jump targets throughout your entire program every time you insert or delete code. That's just hell.
(on a completely different CPU) I memorized the opcodes rather quickly, and surprised myself by writing the hex code instead of the mnemonic on the coding sheet.
This also gives you the power to read code in hex dumps!
The production quality is so much better than somebody with 300 subs. Awesome job.
Thank you! That is very kind. And in fact four days ago there were only 3 subs :) so the algorithm isn’t all bad I guess. More of this to come, anyway. Thanks
Thanks for making a video about this! I had never heard of Sphere before. Not to mention that the 6800 really did end up in the minority compared to the 8080, then the Z80 and, of course, the venerable 6502. The much lower price of the latter being a huge factor there, I assume. Still, the 6800 was a neat little microprocessor, and seeing videos being made about systems that used it is really cool.
Wow. The fact it has 512k of video memory in 1975 is something special alone.
Well… just 512 bytes. :)
@@bzotto I thought so. I best watch again. Sure I heard a "k", but probably on me. Thanks for the reply.
Fantastic work! Bravo!
Very advanced and modular for its time! The motherboard seems extremely efficient and though there isn't as much to deal with in terms of jumpers, connectors and so on as there is today, its design is very easy to work with...even for someone not proficient in architecture who needs to be trained quickly. I like how also for obvious reasons of the era it was made to double as a dummy terminal. The command keys are also quick and easy. I bet a novice could also learn assembly language on it with only minor headaches. Thanks for the video!
Thanks! It is in many ways definitely a quirky design, but the fairly strict functional modularity of the hardware does make it pretty easy to get your head around. The firmware for the dumb terminal mode seems to be lost to history, unfortunately (if anyone out there knows where I could find it please get in touch!).
@@bzotto
I'll research the firmware yes and try to find a forum or something for hooks in the water.
Actually maybe you could tell me what firmware it takes? I've never learned much about old "dock terminals" as my college math teacher used to call them.
But I love soaking this retro stuff up like a sponge. 😁
Thanks for making this deep dive!
Thanks for sharing this. What a neat computer.
I really enjoyed this! Thank you for being clear and concise and covering a lot. I hope you make more!
Great job on the video! Now I have a much better understanding of what it is we’re working on :)
Comment to boost the algo! Great content
Very cool. Great video on a cool machine I'd never heard of. Can't wait to see more!
What a great machine, thank you for the Video.
Very cool and interesting. Subscribed and thanks for sharing
Interesting video - you showed the hardware & software very well. The custom cables were a nice touch!
Thanks! (Re the cables, every excuse I find to use the panavise makes it feel slightly more like a justifiable investment)
Amazing video! I love computer archeology! You just got a subscriber from Brazil!
Great job. Thank you.
Now that was very interesting, TY.
That's awesome, why have I never heard of this system. Though I held my breath a little when I saw the boards flex, when you pushed in the ribbon cable connectors.
😂 I promise they’re quite sturdy. Glad you enjoyed!
great video, thanks!
Wow great informative video. Thanks for the effort! As an oldie it's nice seeing these older systems getting some attention again.
I can't remember ever hearing of the Sphere computer maybe because at the time I was still at school (UK). In 1979 I left school and started work in the IT department of a major insurance company. At the time they used both ICL and IBM mainframes. It was at this time I became aware of personal computers and bought a Nascom II.
Recently I bought a PiDP-11 and Altair-duino so I can relive the old days.
Someone ought to make a box that has different old computer panels on different faces, so you have a PDP-11, PDP-8, Altair 8800, etc. just by turning the cabinet.
The most remarkable thing about it to me was the fact that the company that made this thing couldn't spell "copyright" or "origin".
Well what the hell happened? Way ahead of its time. Why aren't we all using Sphere computers now?
A great question-- there are multiple interconnected answers. Most mundane is that like so many small startup manufacturers in that space at that time, financial and production headwinds were strong and ultimately couldn't be overcome. The systems themselves were rather flaky out of the box-- the ribbon cabled bus and power design turned out to introduce all sorts of difficult-to-debug glitching unless you were very very careful. So plenty of users (and reviewers) were warm on the machine but needed to do a fair bit of bespoke jerry-rigging to improve the reliability. Finally, bad luck: Sphere showed up before the S100 bus was established, and as it happened, the Altair's design and CPU choice resulted in a large standardized ecosystem of hardware (and software). The Motorola 6800 machines were just a smaller universe.
@@bzotto Yes, I watched the lecture video. Thank you. A few years after this, just entering high school, I got a Commodore 64, and my best friend got a TRS 80. We had a lot of fun with these. Unfortunately, neither of us stuck with it.
Short answer, they went bankrupt.
Finally, a video with low views that's not hot garbage. This actually looks great, just shared it in the retro tech Discord server I'm in.
lol, and thank you :)
That's one cool machine. I'm sorry I never heard of it. It would seem to be a bit easier to "live with" than the more famous Altair. 👍😊👍
Look forward to the next instalment
Awesome! 😅
I would love to see this computer on woodgrain cabinet.
Thank you for this video. So interesting! I hope you keep it up. I definitely subscribed to you.
Thank you Steven! I did this one as a sort of extracurricular for the book I'm working on but I've been delighted that there's a real audience for this sort of information in this form. More coming soon! Thanks.
Good presentation. That is a great system that I was previously unaware of existing. One thing to me that is a little confusing is when people read hexadecimal numbers using decimal terms. I.e. reading 0x400 as four hundred, etc.
Glad you enjoyed- how do you tend to speak those numbers out loud? I’ve been using hex for like 25 years and I’ve never felt especially confident or consistent about that, which I suppose comes across in the video :)
I really enjoyed the videos on this computer system. I'd love a deeper dive into how the CRT board works. The whole thing feels very similar but more capable than the Apple 1
Thanks, and I like your suggestion. The CRT system is interesting on its own terms. At heart, it’s a very faithful implementation of Ed Colle’s published “TV Typewriter II” circuit. Sphere swapped in Motorola RAMs for the text buffer and connected those to the main system bus. The upside is memory mapped video (fantastic!), but the downside was no bus/access locking so you end up with white “snow” when software updates the text. The other downside is it inherited the 32x16 resolution which may have seemed ok for a TV Typewriter but is really too cramped for nontrivial software.
The Apple-1 design uses essentially a serial terminal display circuit for its video because Woz had a design of his own for that already hanging around. It had a higher and much more reasonable text resolution, but could only output text serially from the bottom of the screen like a typewriter (and I believe rather slowly as well). Woz was a gifted designer and his system ran very well for what it did, and in the Apple II he moved to memory mapped text at good resolution and cleverly used that for RAM refresh as well, a very smart design that was better than many predecessors including the Sphere and his own Apple 1, but that was two years later.
Anyway, great thought for a deeper dive. Stay tuned…
@@bzotto it's certainly an interesting topic, I was wondering about the access and the snow. Now you have pointed it out the Schematics for the sphere CRT board are of a very similar layout to the TVT: 2 . I have been meaning to build a TVT2, but unlike the 1 it's not modular with as much testing and documentation.
I look forward to more of your thoughts on the sphere!
I've never heard of this computer before. Thank you for making this video and sharing it!
I loved the various systems from the 70s and 80s, I learned alot from them!
The real education started when I got a job servicing 'main frame' computers in 77!
It kinda fell apart when the management didn't like the tiny microcomputers, as they were too small for business use!
IBM came out with a similar system a year after our engineer designed the award winning microcomputer system!
I still use the knowledge today at my home shop!
Way more funny computer than the computers that came a bit later with BASIC build-in.
It make me think to Texas Instrument and Hewlett Packard calculator of this era.
That editor is a thing of beauty. Almost makes programming assembly a joy. Thanks for the video, hope to see more on this computer!
When I got my Atari 800 as a kid, it had a fullscreen editor like this where you could move back up over what you'd typed and change it. I was surprised that most computers had nothing like this. When it comes to firmware features, I'd love to know where the early microcomputer designers got their ideas from.
"Joy" might be bit of a strong word! But it was certainly easier to work with than toggling in with switches. Users created "full" (mnemonic) assemblers very quickly for it, and I'll hopefully show one of those off in future.
@@bryede Fullscreen editors require memory-mapped video, and that took a while to become standard. The early systems (teletype based) all used line-based editing-- which stuck around for a while as a standard paradigm even on systems that eventually had more capable facilities.
@@bzotto I've been watching Usagi Electrics video on the Centurion mini computer and I'm comparing it to the editor on that. A good text editor is always a joy. 😂
a multi-ribbon cable bus - that is so weird!
There is a precedent, the PDP-11 had a few different flip-clip modules with dual ribbon cables to connect two busses together.
Wow! I must say, quite advanced for 1975, especially for the full-screen "back scrollable" editor built-in with a "crude assembler" which is ... hmm ... "kind of integrated". With more ROM (I guess ROM was not so much cheap back to then either ...) they could do even more, but even in this form is impressive.
It depended on the proms used, as to the cost.
I cut my teeth on such systems in the 70s and 80s, and I learned more with 'main frame' computers based on the 7400 IC family.
Looks like I have to buy another book about an obscure computer.
😂 So real. (You should see my bookshelf)
Very interesting! I remember seeing Sphere advertised in magazines like BYTE and Kilobaud, and I wondered what became of the company.
If you want detail on what happened to the company, click the linked video (in description) to a talk I did at VCF West last year. Like so many small manufacturers of that era, they ran into financial and product headwinds and didn't make it (gone by 1977). But the long term thinking was there.
Always wondered what preceded the Next Cube
Most of us who were early adopters... just got totally burned. Over and over and over again.
SiIlicon valley snake oil. I've got barns full of antiques like these all completely obsolete.
When the computer revolution tanked in the late 1990's, nobody looked fondly on these old machines. So they all came to me to die. I collected one heck of an elephant graveyard, because these had been $$$ unobtanium for me when I was a kid. I haven't touched them in decades because it's just too much effort to dig a single one out, set it on a table, and plug it up and into a power socket.
And why? When you've got an 8 core CPU with 32gb back in the house and a non-performing youtube channel to run.
And ironically, it’s rectangular…
Despite being born at the tail end of the 90s, I find 70s microcomputers to be really interesting. It was the wild west, everybody tried everything.
100%
Never heard of the Sphere. Other than the CRT output, it's very similar to the Heathkit ET-3400 Microprocessor Trainer.
Ok this one takes me back, though my recollection from the documentation they sent me was for the "Sphere 300" of which they sent me about 60% of the pieces before their bankruptcy notice arrived. I was in high school with very limited resources so needless to say that system never ran, but I still have a CPU and CRT board, and the power supply is still on my work bench though it's been a couple of years since I built anything with it. These days it's all Raspberries and Arduinos.
Nate! Thanks for the comment and recollection. I'd love to talk to you for the book project about your experience at that time-- could you get in touch with me at bzotto at gmail ? Or another means via the sphere.computer site? Would love to learn more. Thanks.
The development environment is pretty brutal. I understand why people were ok with Basic despite the major perfomance hit
Totally- BASIC was a massive step up from the “raw” environments on the earliest micros. It also opened up the “home computer” to people who were not fundamentally engineers. That’s such a crucial historical rubicon. In any case, the sphere did have a BASIC eventually (actually a few of them) I’ll talk about that in another video soon
The TRS-80 color computer used a 6809 processor and PIA 6821s for IO read and control. What did the Sphere use for memory management and access? The CoCo used a SAM chip (6881 or 85?). It was a reference design from Motorola.
Sphere used a 6820 PIA for keyboard interface.
wow with crt board
Never heard of the Sphere, but I'm pining for the CP/M debugger (DDT) on an Altair or IMSAI right about now...
If you start a Patreon, I will be your first patron - this is quality work that should be funded monthly!
Thank you for the kind words. Keep an eye out for followups soon!
Not directly connected, I remember mentions of the S100 bus in Byte magazine, something I was reading while I was figuring out how to use the Apple ][ Plus I bought in 1979. Was the S100 bus available when the Sphere was developed, affordable to use, and could it have solved that connecting the boards problem?
That’s a great question- no, S100 was not standardized at that point. The S100 bus was essentially just a standardized version of the Altair’s original bus, and gained popularity on other systems organically because of the Altair and IMSAI’s popularity. At the time the Sphere was designed, the Altair magazine cover was only a few months old and there were almost no other micros available. On the original Altair itself, the slots also required tedious and error prone wiring of the connections (they improved this later). The idea of a hard backplane with edge connectors was around at the time but probably did not seem “obvious” as the only real solution for a bus design. The sphere sockets and cables were likely cheaper on a parts cost basis and had the benefit of scaling in cost with the number of boards you needed. It’s only really in retrospect that it’s clear this was a bad tradeoff with reliability. By the time Sphere shut down, the S100 bus was ubiquitous for 8080 systems and SWTPC’s similar “SS50” design had become popular for 6800 systems. I think the incompatibility of their hardware with any third party ecosystem was not really a deliberate choice but was additional headwind that Sphere ultimately struggled with.
@@bzotto Great explanation, will have to check out more of your stuff.
@@shorttimer874 Thanks, I'm a sucker for this history. There will be more Sphere related stuff to come on my channel (such as it is) here, but in the meanwhile I gave a talk last year about Sphere's history (you might be interested bc of somewhat more industry context) at a VCF event and that's linked in the description above here. Guy on stage doing a lecture with slides is less sexy but it is more detailed and hopefully not entirely dull. Cheers and thanks.
8:48 How does the "scroll stuff off the screen to put it in memory" work? I'm guessing there's a small display RAM buffer that isn't normally examined by the assembler.
Great question. :) The editor scrolling is managed by having the offscreen stuff in regular RAM (obviously), and shifting lines in and out of the "visible" video RAM buffer (which is at a fixed address and lives on the CRT board). The assembler simply doesn't include the additional smarts to traverse all the segments, so the result is the requirement to scroll code up offscreen which lands it all in one consecutive place. The entire ROM is only 1K-- it's a remarkable feat of software engineering, and there are a bunch of serious user-unfriendly limitations as a result. In practice, serious users very soon created full (mnemonic) assemblers that were more commonly used.
@@bzotto I wonder how big the user base was at its peak.
Do you have the schematic of the boards? It would be a great project to build these boards.
There are schematics and other information linked on my resources page here: sphere.computer/resources Unfortunately, a bunch of the key parts are obsolete and would be tricky to find for cheap. But the design itself is probably not super complicated.
What was Apple's invention with Apple I, when one compare to this? Was it mostly the affordable price, or the integration of CPU and video driver on a single board
¯\_(ツ)_/¯ Lots of small companies (Apple included) were trying out lots of different ideas in that era. So much creativity happened in such a short time period that it gets difficult to track what innovations came from where and what ultimately mattered -- so much was "in the air". Apple 1 used the brand-new 6502 (one way to think of it is as a cost-reduced 6800) which was much cheaper. It also had less ROM/firmware but yes, video on the same board. It was aimed at a different kind of user than the Sphere was, which drove its design. I tend to think the Apple 1 (which was both later and had fewer customers than the Sphere did) is mostly significant in retrospect as Apple's first product and thus an important part of industry lore. (The Apple II, however, was rather groundbreaking in hardware design and in backing/marketing/production-- the rest is history.)
I wonder how easy it would be to replicate this system into new hardware - using PCBWay for example?
I suspect the boards would be fairly simple to recreate. Unfortunately several of the key components are long obsolete-- they're certainly floating around but not necessarily inexpensively, or in quantity. It uses the same character generator as the Apple 1, which is $$ these days. The SRAM, DRAM, and the EPROMs are all very obsolete, obtainable at some cost. The rest of the TTL logic is out of production but easy to get. You'd need a way to burn the 1702A EPROMs which is a pain although I'm happy to plug eprom-hut.com , my tiny side-side-side project born out of this project in fact. ;) Etc Etc Etc. To be totally honest it's not clear to me this one would be really worth the effort on net, but I do wonder whether some clever redesign work could make it cheaper/easier.
At 9:35 you mention you do a reset, but I'm mystified as there was no mention of how this is done. There's no visible pushbutton switch on the CPU board, and you had no external cable to a momentary switch????
Sharp eye. I didn’t want to complicate by discussing in the video but: the sphere used a multi finger key combination on the keyboard to trigger the soft reset (they later claimed, not unfairly, that they were an early precursor to windows’ Ctrl-alt-delete). In the video, I am not using an original sphere keyboard, but the reset line is still available on the connector. So the keyboard adapter I’m using is set up to map ctrl-alt-del (ironically) to pull the reset line low, which ends up having the equivalent desired result.
I should probably email you, but I'm popping in to ask if you have Gerber for the CPU board and CRT board? Or measurements for the board size? I've been remaking the schematics in EasyEda and figured I'd ask.
The CRT board using the four chip selection lines is very clever- I was redesigning it to use a single SRAM
Yes do email me! (Addr on my site or on the YT about page for this channel). Neat. I don’t have anything digital for the original boards. They’re all 8x10”. There are decent size photos on my Resources page.
@@bzotto thanks! I have been working from the photos as some of the schematics are a bit fuzzy
@@colonelbarker lol the schematics are awful!
@@bzotto I'm grateful to have them, I'm repairing a TAB Terminal at the moment and the internet won't even acknowledge it exists and there are obviously zero schematics! Your enthusiasm for the Sphere is infectious
11:10 I was gonna say, there must be some built-in code that you are calling to do what you are doing.
Yep, and I misspoke during the video- the checkout program can convert *to* any base, but the input is limited to the numeric formats the firmware routines understand- hex, decimal, and octal only.
I couldn't tell by the video but, can you tell by looking at the boards as to whether or not the traces on the boards are hand drawn and then etched?
They were certainly laid out by hand, although surely used the ready made stickers from Bishop Graphics for at least the standard component footprints. I’m curious why you’re asking, can you elaborate? You may want to look at closeup images of the boards at sphere.computer/resources (scroll to “gallery”)
@@bzotto I grew up during that time period with Heathkit, cosmac, and Osborne computers. The Heathkit and Cosmac my father and I built and you could certainly tell the traces were hand drawn in places which I really admired the work involved. I'd never heard of this computer before so it's really interesting to me; there were so many made during those times that got little press and therefore little recognition.
@@tommyvanpelt2408 Very cool! I also love really raw hand drawn traces like ones with arcs that you rarely see. And I agree, there were so many ideas "productized" at that time, so many people started little companies that didn't make it and then became footnotes or forgotten. Sphere is part of the histories, although it's usually just a passing mention since they didn't' make it beyond early 1977.
@@bzotto very true! I don't have the Osborne anymore but I have every Heathkit we built: an H8, an H89, and an ET-3400 trainer as well as the cosmac. All are functional but the H89 needed surgery to bring it back to life; many tantalum capacitors and about 4 voltage regulators on the terminal board, and the bridge rectifier in the power supply all had to be replaced. The split-octal was something quite different on the H8 and I really don't know what we saw in that machine back then other than the store was more like a spot to chew the rag on the weekends. I'm watching your other videos on the sphere origin currently. When do you expect your book to be published?
What did one of these cost back in the day? I'm guessing a lot more than an Altair.
It was not much more, and depending on the configuration could have cost a bit less! Doing apples-to-apples is hard because the setups were quite different, but the entry level "hobbyist" Sphere kit (aka "Sphere 1") which included the two boards shown in this video, plus a keyboard, power supply, cables, manual etc was $650 for intro offer ("$860 full"). The Altair base kit plus 4k memory kit (equal to the Sphere onboard default) was about $700. The Sphere kit at that tier didn't come with a chassis or TV/monitor, and the Altair kit had the sheetmetal case but only the built-in switches and lights for I/O. So depending on what you were looking for, you were in the same dollar range to get started.
To be fair, Sphere's intent (not fully realized) was to sell to small business more than enthusiasts, so they came out of the gate trying hard to market more sophisticated systems, including not just the full enclosure chassis but ultimately peripheral systems of cassettes and printers and disk drives etc. Those could have easily run into many thousands of 1975 dollars if you went all in on an early order. (These were delayed in availability)
What is the memory address for screen RAM on the Sphere?
It's 512 consecutive bytes mapped at $E000
Never heard of this one. Excellent Video!
Hit that Sub button! Let's see what else ya got!
ive never heard of this, really cool computer! but unfortunately not as spherical as i was imagining...
When you say 4K of ram do you mean Kb or KB ? as in bits or bytes?
bytes. 4k standard on the CPU board. The system could be expanded with additional memory boards up to (in practice) 56k. Most "serious" users had 20k (4k + 16k expansion)
8:04 - an "original" typo?
Indeed it is- that’s from the user manual. I think the best understanding of it is that tiny startups in the mid 70s had the engineers type up the instruction sheets and no one had the time or inclination to copy edit before xeroxing to ship out
Why not do the usual " Hello world" program
Touché
The Sphere pre-dates Kernigan&Ritchie. Kickin' it really old school here.
Compared to modern computers Sphere microcomputer resembles a primitive ape compared to modern humans. All that evolution in less than 50 years! Guess what the next 50 years will be like.
I think today we can easily build a more capable computer than Sphere and tiny enough to fit it inside a white blood cell.
No need for a CRT, it will plug in directly to the optic nerve with HDMI-5.0
> Called Sphere
> Is a cuboid
mfw
Do you realize that nothing in that computer has made in China printed ?
For what it's worth most of the 7400 series logic chips in my kit were labeled as being made in Malaysia. I remember it made them seem exotic.
I never heard of the Sphere Microcomputer before, and now you told me what it is I know why I didn't hear anything of it before, it simply is not good enough to function as a computer.
The Altair may haves missed a screen, but it had blinking lights. The Sphere may have a build in screen, but it lacks all functionality, it is not appealing, there is nothing interesting in the basic system. Useless is a big word, there is only a small potential but it is remarkably good hidden.
Meh, my mobile phone is smaller and more capable than this
If ya can’t play Pac-Man I’m out…
Don't count it out yet! I wrote a Snake game which runs just fine. Because it has memory-mapped video, you can do arcade style games. (Unfortunately just text mode symbols.)