View Full Version : 50th Anniversary of "Tennis for Two"
All,
I'm hoping to recreate "Tennis For Two" as it was originally implemented (http://www.computerspacefan.com/TennisForTwo.htm) at Brookhaven National Laboratory. If anyone is familiar with the components and schematic conventions of the era, your help would be greatly appreciated.
Thorn
07-31-2008, 03:51 PM
All,
I'm hoping to recreate "Tennis For Two" as it was originally implemented (http://www.computerspacefan.com/TennisForTwo.htm) at Brookhaven National Laboratory. If anyone is familiar with the components and schematic conventions of the era, your help would be greatly appreciated.
The schematic conventions are no different than today's. However, that page has only two out of three schematic sheets needed. In particular, the gates circuits are all missing.
streaker69
07-31-2008, 04:04 PM
Thorn,
Don't you still have the original copy that you wrote on the back of a cocktail napkin that you gave to those guys before they built it?
Thorn
07-31-2008, 04:14 PM
Thorn,
Don't you still have the original copy that you wrote on the back of a cocktail napkin that you gave to those guys before they built it?
Uh, no.
Seriously, the fun part was seeing Ralph Baer (http://www.ralphbaer.com/) on the History page of that site. Mr. Baer designed the first consumer video game platform, the Magnavox Odyssey. He also wrote the Foreword for Joe "Kingpin" Grand's book Game Console Hacking (http://www.amazon.com/Game-Console-Hacking-Voiding-Warranty/dp/1931836310), to which I contributed.
I've been unable to find anymore than those pages. Of course now that you've mentioned an additional page, I see that they're numbered one and two respectively. I wonder if anyone is up to the task of recreating the magic without the 3rd page.
Of course, knowing the resourcefulness of this bunch, I wouldn't be surprised to have the originals turn up at the Riv.
Thorn
07-31-2008, 07:17 PM
I've been unable to find anymore than those pages. Of course now that you've mentioned an additional page, I see that they're numbered one and two respectively. I wonder if anyone is up to the task of recreating the magic without the 3rd page.
Of course, knowing the resourcefulness of this bunch, I wouldn't be surprised to have the originals turn up at the Riv.
Yes, plus they're also marked "1-3" and "2-3"
I misspoke about the "gates". Those triangles aren't gates, but amplifiers. A typical signal amplifier built out of discrete components circa 1958 would have been something like on this page: http://www.st-andrews.ac.uk/~www_pa/Scots_Guide/experiment/lab/expt5/page1.html But even recreating those, there seems to be some information missing. For example, on page 2, there are six inputs marks as "to output of computer." I'd guess it's some sort of TTL output, but what exactly?
Yes, plus they're also marked "1-3" and "2-3"
I misspoke about the "gates". Those triangles aren't gates, but amplifiers. A typical signal amplifier built out of discrete components circa 1958 would have been something like on this page: http://www.st-andrews.ac.uk/~www_pa/Scots_Guide/experiment/lab/expt5/page1.html But even recreating those, there seems to be some information missing. For example, on page 2, there are six inputs marks as "to output of computer." I'd guess it's some sort of TTL output, but what exactly?
Those are listed in the notes on page 2 detailing their assignments as ball, net and court horizontal and vertical, which are accounted for on the right side of page 1.
I have a feeling page 3 has all the amplifier circuits as well as additional power circuits for the other inputs on there like +/-75V, 60V DC, +DC, etc.
I'm actually going to call Brookhaven tomorrow and see if I can convince them to pull the schematics out of the Raiders of the Lost Arc type gov warehouse they're probably stored in so we can give them a go.
Here's hoping.
Well, I've received a response from the administrator of the site where I found the schematics. He was directed to them by an author who had the links sent to him by Higginbotham's son.
The archive.org links he provided for the source of his images are no longer in the archive and Higginbotham's son suggested that the original blueprints may not be available any more.
I'm going to try the lab just the same, but if we can't get the last page of the diagrams, is anyone willing to try and recreate the missing circuits in a manner consistent with what is present?
I realize those 10 amplifier sections are going to be the most complex parts of the circuit, but it seems a shame to walk away from a challenge like this.
I called the lab and spoke to Regina in the visitors center. She's passed along my request along with the link to Brookhaven's write-up on tennis for two to the instrumentation lab.
http://www.bnl.gov/bnlweb/history/higinbotham.asp
Per that page, the bulk of that analog computer was 10 operational amplifiers that could be configured to simulate ballistic motion. Being that it was made in 1958, they're pretty much guaranteed to be double tube op-amps.
I've also found the name of one of his collaborators on the project: Robert V. Dvorak
His grandson posted in a discussion about tennis for two earlier this year and mentioned that he thinks he has some of the original schematics around. I've asked the site's operator to contact him on my behalf.
Thorn
08-01-2008, 01:16 PM
Per that page, the bulk of that analog computer was 10 operational amplifiers that could be configured to simulate ballistic motion. Being that it was made in 1958, they're pretty much guaranteed to be double tube op-amps.
Could be, there was a lot of mixed tube and transistor circuits back then. If it's true, replicating the circuit might not be hard to do, but getting the tubes themselves may be difficult and costly.
Problem is, until we have the circuit re-created, I would have no idea which tubes to find. I know several people around town that have older electronics on hand and I'm sure plenty of DefCon folks have relevant components. Let me know if you come up with any ideas, I'll keep working on getting the rest of the schematic.
Thorn
08-01-2008, 01:41 PM
Problem is, until we have the circuit re-created, I would have no idea which tubes to find. I know several people around town that have older electronics on hand and I'm sure plenty of DefCon folks have relevant components. Let me know if you come up with any ideas, I'll keep working on getting the rest of the schematic.
I'll ask my father. Dad was an EE for Raytheon in the 1950's before he moved on to other things. He still talks about using Nixie tubes for digital readouts.
If anyone else cares to look into finding the schematics, It was designed by William (Willy) A. Higinbotham, built by Robert V. Dvorak and the schematics were created by Alexander Elia.
Higinbotham died in 1994 but his grandson had contact with authors detailing the history of the game, Dvorak died in 1969 but his grandson posted to this discussion about his grandfather's involvement:
http://simondvorak.com/2004/12/17/robert-v-dvorak/
I haven't found any further mention of Elia yet.
I've contacted Brookhaven National Laboratory public relations and was directed to an engineer who has been tasked with recreating Tennis for Two for it's 50th anniversary. He's on vacation until after DefCon (maybe he's going?), but I was told that he is answering his email. I've sent off a message inquiring about the missing schematic page. As soon as I know more, I'll let you know.
The public relations person I spoke to also mentioned that they had to hit eBay for some of the necessary components. Should we get the schematic and re-create it, I'd like to find out if they are still missing anything and send it along to them if we have it.
Please follow up on this. I would be interested in building it. At the very least I could design a replacement, but it wouldn't be the same as recreating the original.
Thorn, you can still show this year you know :)
LosT
Please follow up on this. I would be interested in building it. At the very least I could design a replacement, but it wouldn't be the same as recreating the original.
Thorn, you can still show this year you know :)
LosT
No response from him yet. I have a feeling we're SOL for doing this at the convention unless we're recreating it on our own. A shame really.
If/when I do get the remainder of the schematic, I'm all for building the original. I live walking distance from UAT and have at least one friend that wants to do this as well. I'm sure we can meet up and make it happen on our own.
Thorn
08-03-2008, 02:41 PM
My dad just left, and we discussed tube op amps. although he said some transistor op amps were coming into play in that same period. He said he still has his design books from those days (both tube and transistor) and would see if he could find some representative circuits.
Thorn, you can still show this year you know :)You have no idea how much I wish I could. :cry:
Make the wish come true :)
LosT
I heard back from Peter T with BNL. The Op-Amp sections of that schematic are all part of a Donner/Systron Model 3000 analog computer. In reading some of the write-ups on the history of the game, the ball movement was based on bouncing ball circuits described in the manual for the computer.
If anyone can find a wiring diagram for that machine, we can go from there. He also mentioned they may use a model 3400 which is electrically compatible. He's offered his assistance via email, but he'll be unable to use it after Wednesday and he graciously provided a personal cell number as well.
Let's see what we can do with this.
Got another reply from Peter at BNL. He confirmed that all 10 of those Op-Amp sections are black box interfaces in the Donner 3000. He also mentioned that they have a schematic for not only the Donner but also a period Philbrick op-amp that can be made with 12AU7 tubes and standard passive components. Giving us the chance to look in the black box and recreate as needed.
I've asked for his co-worker's email in the hopes I can get scans of both schematics. With those, I think the only thing that would keep us from building this during defcon is component availability.
SmittyHalibut
08-06-2008, 10:31 AM
You think you can get tubes by this weekend? Anyone know of a source for tubes in Vegas?
I used to work for a company in Mtn. View called HalTek (not to be confused with HalTed or HSC) that had a HUGE stock of NOS (New Old Stock) tubes. But HalTek closed down years ago; I have no idea where their collection of tubes ended up. I know there are places on line you can order tubes from, but that probably won't do us any good by this weekend.
12AU7 never went out of manufacture, you can buy them at guitar center. Not sure if I'll be able to afford all these components though.