I need nothing of that since I have the net. I can find any info I want or any kind of circuit I may want, I cannot understand how magazines still exist, in the common sense of the word! Maybe for ads, who knows? :o?

You mean sort of like this list lately? William Donzelli aw288 at osfn.org

ADdress Strobe? -tony

Don Y wrote: "For sale -- PDP-8 blah blah blah $800 would be nice." More like Drool over the last bunch of NOVA's I got for a song at the Ham Fest.

On 6/12/2006 at 8:02 PM Jos Dreesen / Marian Capel wrote: There's an outfit that I sometimes do business with--Futurlec (at http://www.futurlec.com/ ). As near as I can figure, order processing is done in New York, but shipment is done from Thailand. It's odd--I still get my orders in about a week, so maybe globalization works. They also carry the Aussie "Silicon Chip" magazine. Cheers, Chuck

woodelf wrote: It is not on the web, and since Elektor is still around, copyright issues do arise. You might want to look for the issues from may 74 until january 75 to have the complete set of articles. They do appear from time to time on european auction sites. Look for "elektor", "elector" and "elektuur" (original Dutch version ) Jos Dreesen

Philip Pemberton wrote: For the 12 bit version you have a whole 8K words of memory -- lucky you. Looking at some old GODBOUT ads on the web about 1975? -- 2102 had dropped to $1.95 -- my guess about $6.00 today each.

FWIW, in 1972 the UK magazine 'Practical Electronics' published a design (going over 10 issuses, I have the whole set) for a TTL-based 4-function desktop calcualtor. Not a computer, sure, but a lot of the principles were there. I'd love to see that, but my Elektor collections starts at about the time of the first Elekturscope (and I don't have a complete run since then, alas) -tony

Tony Duell wrote: Not if you happen to live in Leeds. The trade counter's open to the public and it's about ten minutes' walk from one of the stops on the main Armley Road bus route. Order at the desk and wait 20-40 minutes (depending on order size) for them to sort it, or ring ahead and it'll probably be ready by the time you get down there. All you really need is a Customer ID number - ring main sales and ask to register for one. Simple as. When I was over in the States a few years back (2001 I think), I picked up a few packs of resistors from the 'bargain bin' at Radioshack. Yes they're probably crap quality, but they work well enough for most things. When I need a value I don't have, I usually order a strip of 50 or 100 of the 0.25W metal-film variant. ?1 +VAT for fifty resistors - certainly beats Maplin's extortionate 70p for ten. I've still yet to find a place that sells nickel shim stock though (I use it for battery welding strips). I used to get it from McMaster-Carr, but they won't do export orders any more. Around here there's Farnell and the local Maplin (spit). Apparently there's also Bardwell's in Sheffield, but I don't know if they're still going. Now what I would like to find is a decent supplier of electronics surplus. Mainline were great up until their warehouse caught fire, Greenweld have disappeared (good riddance, their Innovations-catalogue wares will not be missed) and WCN don't seem to have much useful stock these days. Nor do they seem to want to send me a copy of the current catalogue... EPE's a shadow of its former self. They won't take freelance submissions any more, and 90% of their content is from Silicon Chip magazine. I fully intend to let my subscription lapse when it's up for renewal. Elektor is neat - their "no you can't have the firmware source" policy is a bit crap though. They do publish more interesting stuff than EPE, and I find myself spending longer reading an issue of Elektor than I do an issue of EPE (I also tend to make a hell of a lot of scribbles in my 'neat circuit snippets' notebook while I'm doing so). Circuit Cellar is good too - kinda like an Americanised version of Elektor, but with more "this is a cool trick" type articles -- the current issue has the circuit diagram and firmware for a neat-looking motion-sensing glove based on an AtMega MCU. They've had other stuff too (too much to list), and Jeff Bachiochi's "From the Bench" column is usually worth reading. I've got a box full of homebrew adapter PCBs and turned-pin solder pins. When I need to put a particularly fussy chip onto a breadboard, I make an adapter in Autotrax and etch it. It takes longer, but it beats dead-bugging fine-pitch chips. On the software front, I just ignore anything that needs expensive software. I once had the 'pleasure' of dealing with an FPGA vendor who was screaming about how cheap their ICs were. I asked how much the development software was, and got the answer "sorry, we can't tell you unless you sign an NDA." Sorry, wrong answer, you lose, thanks for playing. There's a reason all the microcontrollers in my junkbox are Microchip PICs and 8051 derivatives (mostly Dallas Semiconductor "Speed It uP" series chips) - free or cheap dev software. MPLAB is free, MetaLink Assembler is free too, and the Dallas chips are programmed with a MAX232 and a toggle switch. All my CPLDs are Xilinx - the Parallel Cable III schematic is open (it's an LS244 buffer and some passive termination circuitry) and ISE WebPack is free (but bloody huge - about 200MB last time I checked, and the service packs are just as big). I don't really do wirewrap or Roadrunner wiring much these days. My last three projects were built straight onto PCBs, then I patched the inevitable bugs with copper tape and patch wires. If I find an unpatchable bug, I etch a new PCB and move the old components onto the new board. Thankfully I haven't had to do that yet... At the moment I'm designing a 'proper' battery charger. Basically a current-mode switchmode buck converter and a programmable current sink. I got sick of the ?20 Chinese cheapshit chargers wrecking my expensive Sanyo NiMHs, and dying after a year or two of fairly light use. -- Phil. | Kitsune: Acorn RiscPC SA202 64M+6G ViewFinder philpem at dsl.pipex.com | Cheetah: Athlon64 3200+ A8VDeluxeV2 512M+100G http://www.philpem.me.uk/ | Tiger: Toshiba SatPro4600 Celeron700 256M+40G

Resistors are SO cheap that pays for having a parts' tray with one hundred of all values comercially avaiable and being replenished from time to time. This is something you'll use forever. And doesn't get old. Greetz Alexandre, from Brazil, and his thousands of resistors :oD

Alexandre Souza wrote: Greetings from Canada with his one 200 ohm resistor. :)

For me this is the best way to design - you build a module, test it, build another, test, connect both, test, build another module, and so on...

Microcontrollers, PALs/GAls, CPLDs. All come with the security fuse blown. Obviously EPROMs are readable :-) In a few cases, they make the object (binary) file available to program your own device, but not the source. Which is not particularly helpful. Yes, I am well aware there are ways to reverse-engineer some of these devices, but I have to weigh up the effort to do that against the effort to design the whole thing from scratch (and have it just the way I want it). Exactly. Rarely does the published design exactly meet my needs, I want to modify it. And that may mean modifying the firmware too. I don't expect them to support all my old machines, but I wish they'd let _me_ do so by documentign the interface properly. If a device plugs into a serial port and uses the Tx and Rx line conventionally, then I'd like to know what commands I can send the device, and how it responds. Or alternatively, give me the source to the firmware and/or the PC program and I'll work it out. I've heard economic arguments (mostly as a reason for not homebrewing) many times before, and I don't believe it's the whole story... Let me go off at a tangent for a moment. All my life I've been interested in clocks, and one day I intend to make a real mechanical clock. I'll have to get a lot better at machining first, but I still want to do it. Economically, this makes no sense at all. To make a clock from scratch probably needs \pounds 5000 to \pounds 10000 worth of tools (many of which i have, it's true, but I'd still need to get gear cutters, etc and they're not cheap). The metal to make said clock is around \pounds 100. And the result is a much worse timekeeper than a 5 quid quartz clock from the local household shop. But I still want to do it, to learn, and to have the enjoyment of making it. And it appears others do likewise. There's at least one magazine which has an article every month on desinging/making a clock (and other articles on making parts as part of antique clock restoration). There are many books and plans for homebuilt clocks. So I can't be alone in wanting to do this. Now lets get back to computers. The difference in performance between a homemade mechanical clock and a quartz clock is probably comparable to the difference in performance between a modern PC and a homebuilt processor. The tools needed to make a homebuilt processor are cheaper than those needed to make a clock, thouygh. And yet, I've not seen one book or magazine article on making a processor from scratch in the last 10 years. If some people think it's worth making a clock from scratch, why not a processor. I will end with a wuote from a book entitled 'Every Boy his own Mechanic', published about 90 years ago. It's the start of a chapter on a home-made telephone system ' For some years previous to 1914 the constructive instinct and ability inherent in many of us was almost snuffed out because most of the mechanical and electrical things we wished to possess were so cheap that they could be bought ready made. Often the prices quoted were actually below the cost to us of the raw materials, and so we came to think that constructive hobbies were a bit futile. Lots of those cheap things were amazingly good, but some where exasperatingly bad, and the bulk indifferent. Still, we bought the stuff, learned nothing from it, and clean missed all the solid satisfaction that lives for ever in building and contriving and creating Take the ready-made cheap telephone, for instance. How long did it take to get fed up with ringing and asking "are you there ?" Was it really worth the outlay of 15s to 45s? Frankly, no. Why? Because our purchase locked us out from all the subtle mysteries of an ever-wonderful instrument (simple though it may be), and we had been robbed of all the joy of its making. If it failed to act we discovered that we could not put it right. If it acted perfectly, we took the whole thing for granted and soon became bored. But to build up that same installation oneself in the face of difficulties from the homeliest of raw materials, and at last to have it (in litteral fact) voicing our triumph in our eager-listening ears - ah, that is a very different matter!' And that is exactly how I feel about homebrewing electronic devices now. -tony

Having unknown hardware in your hands isn't, IMOHO, nearly as bad as unknown software. Consider my conundrum right now... I've got a diskette with software (no documentation beyond how to stick it in the slot on the machine) for a computer that a customer wants to emulate on a PeeCee, the last remaining sample of the original hardware having flown the coop. No engineering documents at all. The instruction set (from the disk) appears to be 8086, but the OS is unknown to me and from the looks of it, the disk is loaded into memory as a single 240K image. I can figure out the load address by explicit segment references. From the very few ASCII text strings in the code, this is apparently a multithreaded, interrupt-driven OS. or some-such) readout and a diskette drive with an RS-232 port. Otherwise, ASCII searches yeild no error messages, prompts, or anything that would allow me to quickly determine control flow. I have absolutely no idea of the peripheral configuration. This is circa 1981-82. So, where do I start? I could put it on an emulator and attempt to trace program flow, but given the nature of the OS (event-driven) it's not going to be easy. I can locate a few ISRs, and from their appearance, the box doesn't use an 8259 PIC (no EOI sequences at the end of the ISRs). If this were a hobby thing, I wouldn't care about the time I put in--but the customer wants a quote. Any suggestions? Cheers, Chuck

On 6/14/2006 at 11:08 AM Don Y wrote: Develop an emulator for the box itself. Oh, I've already identified the OS--it's MTOS-86--but that doesn't mean it's known to me. The filesystem is CP/M-ish. But the app itself is tied into the OS in a single unified whole--there is only one file holding everything. No NDA here--messages are of the nature "Unexpected Interrupt"--about a half-dozen such things, all of them, your basic debug message-and one reference to an "integrated debugger"--and no application-specific identifiable ASCII in the remainder of the code. My suspicion is that the ASCII is sent to some diagnostic port and not to the main display. But the code referencing the debugger messages might be a place to start. Almost certainly not--figure 18 months average lead time from design to production. I worked with early steppings of the 80186 back then and they weren't ready for prime time yet. Besides, I don't see any references to setting up the relocation block, which ought to be about the first thing to occur. I'm very sure that this is a garden-variety 8086/8088--no 80186-specific instructions to be seen anywhere (e.g. PUSHA). I'd look for I/O devices if I was certain of what they were. No keyboard, just a numeric-type keypad, some kind of one-line display, RS-232 and some sort of interval timer and a floppy drive. The RS-232 was used as a data link, not to drive a terminal. Like I said, if this were a hobby thing, I'm sure I could suss it out given as much time as I needed. But I'm on the clock on this one. Cheers, Chuck

On Wednesday 14 June 2006 12:03 pm, Don Y wrote: Can you elaborate a bit on what you mean when you say "application domain" here? I suspect that this is probably a rather obvious thing to some of the folks in here who are more familiar than I am with regard to older hardware that I have no experience with, where that hardware was more specialized in terms of what it was intended for... -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, a critter that can be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin

On Wednesday 14 June 2006 03:53 pm, Don Y wrote: Ok, so you're talking mostly what I'd call embedded applications then. That's an interest of mine but I've really not that much experience at it and don't know as much as I'd like to about what sorts of things would make a machine better suited to the kinds of specific purposes you're talking about here. Gotcha. What I was thinking when I read that bit about application domain was some differences in the actual processing itself. Sort of like what some of those real early computer books I have were talking about when they referred to "busines" vs. "scientific" computers or something. :-) -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, a critter that can be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin

Hi Integration on chip exceeded the in speed the cost of I/O pins. In other words, if the entire processor model was on one piece of silicon, it could run faster than if it had to run cycle by cycle through the I/O's. Dwight

--- woodelf <bfranchuk at jetnet.ab.ca> wrote: I believe they were used in HP printers.

On Wed, 14 Jun 2006 16:47:35 -0600 woodelf <bfranchuk at jetnet.ab.ca> wrote: I own SGI VME and GIO FDDI cards that use AMD 29k CPUs to do some of the FDDI/SMT protocol work in "hardware". (The VME FDDI cards are modified Interphase Peregrine cards.) IIRC I saw a 29k used as RIP in a laser printer. -- tsch??, Jochen Homepage: http://www.unixag-kl.fh-kl.de/~jkunz/

Well they have had wooden clocks before that! Even with a bell -- Monks had to get up early to pray you know! This is because of the PC -- everybody wants clones and anything other than the 8088/8086 group of processers never impacted the market well. Other than the Mac that shot itself in the foot with only 128K memory total and a closed architecture. I have never been able to find a 2901 processer instruction set I liked that I created. The lack of prom programmer was also a factor preventing me from building a 2901 cpu. (Note a 12/24 cpu looks nice to do with bit slice) I find learning the software and the logic design languages can be a real chore since you really may never know just what the FPGA/CPLD is doing. Umm Soup can's and string ... :) PS. I had a print called "Before high tech there was LOW TECH" and the artist of this art had fun with all the old and forgotton techology for fictional early space craft.The pilot with no space suit had just the WWI goggles and leather jacket but did have a I think a scuba air tank. Wings looked like from the 15 century art. But he did have a radio dish -- connected to a Cambell's Soup Soup can with string. I can't remember the artist how ever.

Chris M wrote: Umm What ever happed to the fake bodies you could put on your old VW beatle. Could one make a Car now days and drive it leagaly on the highway? You know mine -- that is the one with 8 wheels and the steam boiler and the snow/plow in front -- PS. the 8 wheels are need to go ove the pot-holes that breed here.

woodelf wrote: When it comes to "dubber"s, *this* is what you want! :> http://www.ronpatrickstuff.com/

Don Y wrote: No This is what I want -- Sadly I can't read Japanese -- but the picture(s) says it all -- Personal Jet Glider -- This is based on the movie "Nausica? of the Valley of Wind" http://www.nausicaa.net/miyazaki/nausicaa/ for the 1984 movie. PS. Good quality Hi-Fi still seems to be around but alot is homebrew since most people can't afford $$$ for low quality hi-fi. ----- OH ya -- the link for the glider http://www.petworks.co.jp/~hachiya/works/OpenSky.html

Tony Duell wrote: 2901 really only makes sense for a "classic" CPU design. By the time you put all of the parts together to get a complete CPU, it is quite a large solution. Some parts (29116, etc.) could help a little but it still was big. If you don't need a "full" instruction set (traditional ALU, etc.) then there were better ways of doing this. E.g., in one of my CPUs, I needed some cascaded multiply/inverse/multiply operators. I chose to use serial adders and multipliers instead of a more conventional approach. I think it depends on how big the item that you are designing will end up -- and, if it stays a "one of a kind" design or if you ever decide to make several of them. What I find most annoying about FPGAs is they are all sole source parts -- if you have a problem with one vendor's part, you may have to reinvest a lot of time to switch to another vendor's device (as well as investing in another tool chain!) <shrug>

Tony Duell wrote: It was targeted at folks who were buying 4 2901's, 2911, etc. It saved some board space and wiring... [FPGA's] I like prototyping in foil. It seems like I always end up needing a second (or third) copy of a design for some reason. And, having to hand wire a second (or third!) is really not fun. And, for $WORK, I learned that no matter WHAT the client says, he'll ALWAYS want a second prototype for some reason. :-( Of course! The first 50+ reading machines [1] that were built were all wirewrapped. The design was still quite fluid (you kept records of each individual machine since they were all slightly different) so you wanted to be able to make a change on the fly -- as well as IN THE FIELD! Sure, a nice 14" square (? Nova 3) PCB would LOOK really professional. But, when you're stuck in Romney WV on a Saturday night trying to hack a design change into it, you sure as hell don't want to hang around until noon on Monday for something to get air freighted in! OTOH, I've watched hand built prototypes catch fire [2] during testing and the realization that you've got to start all over is more distressing than the fact that you've toasted a bunch of expensive components :-/ [1] Kurzweil Reading Machine [2] You quickly learn the value of "dead time" when switching 100A circuits! :-/

Tony Duell wrote: I've found that one to be the MOST demanding! ;-)