The first "computer" that I got to see up close (rather than at a distance as in "that's our computer over there") was a tic-tac-toe machine that employed Stroger switches. It was mechanical enough to be fun to watch. Wasn't there a turn-of-the-century electromechanical gizmo built by a Frenchman to solve the three queens problem? I seem to recall that when it won, it played a phonograph recording of "?chec et mat". Can someone refresh my hazy memory? Would that qualify as a "computer"? Cheers, Chuck

I found the chess-playing device and discovered, as usual, that I had a few dropped bits in my wetware. "El Ajedrecista" by Leonardo Torres y Quevedo, 1912, exhibited at the 1914 Paris World's Fair: http://en.wikipedia.org/wiki/El_Ajedrecista Cheers, Chuck

dwight elvey wrote: One or TWO's compliment? Decimal or binary? What if I want Subtract and Jump if < 0? I've seen the same site. :) The Ultimate RISC page is here. http://www.cs.uiowa.edu/~jones/arch/risc/ The minimal CISC page is there. http://www.cs.uiowa.edu/~jones/arch/cisc/ and yes 'Sam I am', I'll read them anywhere. :)

On 28 Jun 2007 at 10:36, dwight elvey wrote: There is another class of single-instruction machine, called "move machines" that has actually made it into production products. Cheers, Chuck

William Donzelli wrote: I have two old ones (I'm not including Hayes-and-after in this): - a Bunker-Ramo from 1967/8; discrete transistors and large, canned filters; electrical connection to tel network; about 19"*6"*10". - an acoustic modem built in to a (!) teak box, late 60s or early 70s I think, discrete transistor. Haven't had a chance to play with them or figure out specs, they're in the queue for reverse engineering at some time.

I have a cat modem. I also have a softmodem that one can load a program into. I used it for a DSP project that did filtering and weather fax decoding. Dwight _________________________________________________________________ Picture this ? share your photos and you could win big! http://www.GETREALPhotoContest.com?ocid=TXT_TAGHM&loc=us

In article <Pine.LNX.4.44.0706281038260.22092-100000 at ns2.nut.net>, Doug Salot <doug at blinkenlights.com> writes: What are those big blue things I see on end in the 2nd photo? -- "The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download <http://www.xmission.com/~legalize/book/download/index.html> Legalize Adulthood! <http://blogs.xmission.com/legalize/>

Doug Salot wrote: Yes, they appear to be the same (I don't have mine here right now), except the box on your unit looks more like mahogany. I wonder if that Livermore Data Systems is the manufacturer, or a service bureau at Livermore Labs that used them. I'll send you the schematic when I RE it (not very difficult) if you like.

At 10:19 PM 6/28/2007, Doug Salot wrote: I've got one of those. There's a little magic marker on the outside I need to remove, but with all that wood and brushed aluminum, it sure is retro purty. - John

I rememebr the 'build your own modem for under $50' article in Byte (Circuit Cellar, of course). I also well rememebr the Maplin Modem (a build-it-yourself 300 baud direct connect unit). It used a 14412 for transmit, but they apparently couldn't get it to demodulate CCITT tones reliably, so they added a separate PLL chip for that (XR2211 or something like that). I may still have a couple of brand new, unpopulated, PCBs for this project somewhere. -tony

Mo wrote: Livermore Data Systems for the ones being discussed last week, although Doug suggested AJ may also have produced wood box ones. If you're taking that 'teak' attribution from my earlier statement, I have to modify it: upon closer inspection (an unfinished area of wood) it looks like mine may be a lighter shade of black walnut, finishing stain perhaps making it look a little more like teak (I still think Doug's may be mahogany) (..for what it all matters). I pulled mine (actually identified as a Livermore Data Systems Model A) out in the past week for closer inspection and to produce the schematic. All of 13 transistors - it's about as complex as a portable transistor radio from the period but it probably cost 10-20 times as much (much higher component quality, in part). Component date codes are 1969 to 1970. Carrier frequencies are 1070/1270 (XMT) and 2025/2225 (RCV) so I think it should be good for 300 baud (originate mode). I'm not completely familiar with the relationship of the 103/113/... modem standards vs baud rates (was there one bell standard (carrier frequencies) covering multiple baud rates (110/300) or were there different standards for the different rates?

I've got a few, it depends on what you mean by 'early' I have a couple of the old GPO [1] Modem 2B units; Large metal cases (about 15" square by 6" high) contiaining plug-in PCBs. Modulator and demodualator are discrete transsitors, the control circutry is mostly relays. [1] As in most other conntries, at that time (late 1960's, early 1978's) you had to rent the mdoem from the telephone company, which in the UK was the Post Office (GPO). Some of these modems were actually made by Plessey. A little more recent is the GPO Modem 13, which is a plinth screwed to the bottom of a normal telephone (a type 746 for the UK phone enthusiasts). Said phone has a couple of buttons added to select between voice and data. The plinth contains one PCB with metal-can ICs (maybe custom) and pot core inductors on it. Of course I have a number of 1970's accoustic couplers..... One oddity is the 'barrier box' At one time you had to fit this thing in the RS232 line betwwen your terminal and the (rented) modem. It contained a 50mA (IIRC) fuse in series wtih each signal line and a pair of inverse series zenrs from each line to protective ground (on the modem side of the fuse). The idea was that if something failed in your terminal and an excessive voltage appearsed on the RS232 interface, the fuse would blow before any damage was done to the modem.yes, I have one _somewhere_ I am looking for an old ACU (Automatic Calling Unit) with an RS336 (or is it RS366) interface. I am not planning on using it on a public telephone network, so I don't care about approvals or anything like that. I've never seen one for sale though.... -tony