Eric J Korpela wrote: I haven't played with FPGAs in a few years, so my info may be out of date, but the routing software I used didn't have much to do with sorting. IIRC it They could indeed. All I know is the free?/low cost software is windows based and the hi-priced software is windows/other. I suspect they think if you are not using a Pee Sea you have $$$ to shell out for software. Also using a dial up does not help with the megabyte software needed for FPGA development. As for my hobby CPLD work I just keep adding features to my designs untill it don't fit and go back a version. :) Back to FPGA software for the VAX, I don't see the hardware a problem but the software could be still be one. The small PDP'S has hoards of paper tape software, the big ones all need a OS.

Bj?rn Vermo wrote: I guess nobody even considers building a computer from scratch. :(

I dunno about that, but I once did just that. I took a digital hardware design course, and as a term project I breadboarded a little 4-bit computer. (I think the whole class did likewise, but it was long enough ago that memory is fuzzy.) Only 16 words of memory, and 4-bit words at that, with 4-bit opcodes - not a terribly powerful machine, but an extremely instructive one to build. All TTL; the most complicated building block was a 4-bit ALU chip, a 74181 I think. We also used what were easily the nicest breadboards I've ever used. Real sockets for the chips, with socket pins brought out to jacks that were basically miniature banana plug sockets; the wire connectors were matching miniature banana plugs, and in particular were stackable the way banana plugs are. All the connectors were gold-plated. The bench unit the thing plugged into provided power, clock (frequency settable bank of maybe 16 switches and 16 LEDs...a really pretty setup that was a positive joy to use. Never seen anything nearly so nice since. /~\ The ASCII der Mouse \ / Ribbon Campaign X Against HTML mouse at rodents.montreal.qc.ca / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B

On Wed, 2005-11-02 at 14:16 -0500, Sridhar Ayengar wrote: I took a hardware class where we (each team of 2 students) had to build a PDP-8 using PALs, some 74xx chips, a bit of Static RAM, and a ton of wire wrapping. The final exam consisted of the instructor breaking each machine in 5 different ways and we 3 hours to fix it. That was a pretty cool class. I hear they use FPGAs now in the class...kids these days. Brian

On Wed, 2005-11-02 at 14:42 -0500, Sridhar Ayengar wrote: Yes. That was one of the few courses where I kept the book :) It was still listed last year: http://www.cs.indiana.edu/classes/b441/index.html Brian

woodelf> I grumble that the FPGA's now days have built in hardware woodelf> features that hide real logic slowdowns like external memory woodelf> or slow ripple carry. Not if you connect them to real external memory -- which still is much slower than the logic, just as it has been for the past 40 years or more. paul

Chuck Guzis wrote: I'm using a CPLD ... does that make me half demented? I am also not building a Forth or Risc cpu ... I want my front panel and blinky lights and octal bits. When I was talking about scratch, I was talking about a linux box - console driven. I think there was two in byte. A four bit one and a later 32? bit one. Sigh I miss Killobyte for hardware. Also a TTL computer will be at the Vintage Computer Festival this year. Anybody know how the valve computer a few years back is progressing?

woodelf wrote: About thirty years ago, when I was pretty much younger :-), I built a classical TTL computer (with 74181 ALUs etc.) almost from scratch, basically from schematic fragments from the TTL databook and TTL cookbook and some electronics magazines; well - if it were really from scratch, then even so "highly integrated chips" like the 74181 were prohibited as well. Looking back, this had almost all characteristics of a real computer. There are two aspects IMHO why this does no longer happen today: - what was a known magazine in the past, would today perhaps realistically called "Un-Popular Electronics", the knowledge of electronics from the ground up is dying out; and with the continuing "digitalization" of technology, it is an ever increasing hurdle to get started - the classical AM detector radio I built as a newbie will nowadays no longer attract anyone - you can get a gadget which is better by several magnitudes for a fraction of the expenses you'd have for soldering your thing. - The tools you have are too user friendly (!); i.e. you could rather easily click something together, be it software or VHDL code for an FPGA without ever needing to understand what is really going on. The "soul of a new machine" guys that traced glitches with a logic analyzer in a large wire-wrapped TTL graveyard are gone - such a machine had the necessary wow factor. No surprise when a VAX in an FPGA - see subject - is not really interesting. It is possible - that's it. But what does one gain? It is like solving a 10000 pieces puzzle; spend time and don't learn really much. When Hillary climbed the Mount Everest 50 years ago, it was something new, extraordinary. When tourist nowadays use sort of stairways to reach the top (okay, it's not *that* extreme now), it is just uninteresting. But standing on the top, is still a challenge and an experience for the individual. However, what we lost now is a sense of wonder - that small ALU based TTL circuit was built by myself, and I did it, and it is irrelevant that some idiot could download a digital simulator and click the same circuit together on a PC screen. I guess this is what makes the difference between a real PDP-11 with some ridiculous 5MB storage disks compared to a SIMH emulator running on a 3GHz Pentium. Watch the blinkenlights. Holger

Somewhat OT, but anyway... One of my other interests (it has been for much longer than I've been interested in computers) it horology -- clocks, etc. One day I will make a mechanical clock from scratch, probably to my own design. It will, I know, be a poor timekeeper. A $5 quartz clock will be a lot better. But there is a certain joy in actually making it oneself. Others certainly feel likewise, there are a number of people who make mechanical clocks, there are plenty of books on the subject. I feel the same way about desgining and making a processor. Do it for fun. You are not going to make a faster Pentium at home. Period. You might well make something with a strange architecture or instruction set. You _will_ learn a heck of a lot by doing it, though. -tony

Tony Duell wrote: I should not write postings multi-threaded :-( The argument actually mixes up two ideas; the first is that an AM detector is too mediocre to most people nowadays who are accustomed to FM stereo sound or even 5.1/6.1/7.1/whatever sound even with cheapest receivers. The second point emphasizes on the "digitalization" issue: in the near future there won't be any analogue AM or FM transmissions/transmitters any more; even SW band migrates to DRM now - so success won't be reached anymore with the a variable cap, a coil, a diode, a high-owmed head phone and a reasonable long wire as the antenna. Surely there will be high integrated circuit modules that decode all the stuff, but electronics hobby is not really interesting when reduced to adding a battery to a black box. Of course. Building some gadget from a kit is just part of learning the usage of the tools. I did this in the very beginning, as almost every newbie, but after a while changed to own experiments. Unfortunately, many of the more interesting TTLs are now no longer easily available (you find lots of octal drivers and registers, but almost none of ALUs, multifunction chips, RAMs - even the classical 7490,7491,7492,7493 combo of counters for any purpose is reduced to 7490/7493 - noone needs to divide by 6 ('92) any more - you don't build digital clocks in TTL) - you have to seek for them in specialized mail-order shops. This is no issue for us old farts who play with such stuff for long time, but it is another hurdle for starters. A kit with all parts is much easier to acquire - but then, agreed, soldering is not the fun part of that hobby. Isn't there more than soldering kits? Sure there is, but things become complicated very fast. This wasn't the case in the 70s and 80s when I began. Regards Holger

Hi again. I've just begin to review my Nixdorf 8870. Works, but it don't has any terminal available. I should like to obtain one BA80/84 terminal, or one cable to connect the the Nixdorf to one PC using Kermit (it has BA80 emulation support). I am not sure about the RS232 connector of the Nixdorf, this is the reason. All information (or items like these) will be welcome. Thanks Sergio

COnsiderign the terrible row made by those infernal MP3 players in cellphones that I seem to hear everywhere now, I can't believe many of the younger generation care about sound quality at all. THis ia a great pity, and actually, given the number of cheap radios around, I wonder if it will ever happen. I can't believe the public will accept having to replace doxens of sets. I do still occasionally build kits. I do it if I want the end result, and by building the kit (a) I know it's been built properly and (b) I get a schematic. For example by bench PSU was built from a kit. Yes, I could design one, but actually, the kit was no more expensive than buying the bits separately. Waht somebody needs to do (and it can't be me for obvious reasons) is to select some CPLDs/FPGAs where the download protocol is documented (that is, you can progam the chip, given the binary file, without a proprietary programmer), and use the tools (that's why it can't be me) to make some useful logic functions -- things like an <n> bit universal shift register, <n> bit ALU, counters, even JK flip-flops, gates, etc. Make the binary files available for free download. Anyone wanting to experiment with logic and not wanting to use the horrible CAD tools under an even worse OS, can then program up some chips with the appropriate files and use the resulting devices like the TTL of old. -tony

Jules Richardson wrote: At least this time around we have satellite TV. When the 405-line VHF service was turned off in the 1980s, huge areas of the north of Scotland lost their TV coverage altogether for anything up to two years. Gordon.

Tony Duell wrote: One point I'd take issue with is about digital photography. Go and compare photos taken with an el-cheapo point-and-shoot digital camera and an equivalent 35mm compact. *Then* tell me there's not *some* improvement ;-) Gordon.

Please KILL this thread NOW, as we JUST HAD IT. Talk about computers. William Donzelli aw288 at osfn.org

But entry level digital cameras are definitely better than entry level 35mm cameras. I'm not sure you're comparing like with like here - did you buy the medium or large format cameras new? Look at the new price for these compared to the new price for a good digital SLR - there's not a lot of difference. Or if you value convenience above quality, for instance if you don't plan on publishing 4 foot posters of your holiday photos. Most people simply don't need the quality that you can get with medium format, or even good 35mm for that matter. They certainly don't want to spend the time learning how to use the equipment. It's much the same as the way that most people don't need a Volvo FL12 truck to go to the shops. Gordon.

Chuck Guzis wrote: Yes I think you can still do that with the orginal PAL's that they don't make. If I remember right the early pals were programmed as 512x8 fuse roms. The fuse map was a one-to-one mapping as you have with the logic diagram. The Cypress semiconductor data book has programing information on their PAL's but the data book is from the 90's.

On Fri, 4 Nov 2005 20:31:25 -0800 (PST) "Peter C. Wallace" <pcw at mesanet.com> wrote: An interesting development that I have noted is people selling modern FPGA chips on salvaged boards on eBay, i.e. the chip all soldered onto a card and ready for hobbyists to fool with. I am talking about 'salvage' boards, meaning in at least several instances it looked like the area of the board with the FPGA on it had been cut out with a tinsnips. The FPGA and board was salvaged from some bigger project. In many designs, there is a hole-per-pad zone surrounding the whole FPGA for testing purposes, and the chips can be 'recycled' in this fashion pretty easily. It gives people who want to fool with these chips an easy way to get at them without needing to do any fine-pitch SMD soldering. Sort of the poor-mans 'development board' (i.e. the more pricey eval boards that Xilinx and Altera sell) -- http://sasteven.multics.org/MacSE30/MacSE30.html

The problem with this is of course that the CPLD and even more the FPGA's will be obsolete and unobtainum long before the TTL parts are really gone. You can still buy a 74ls181., but try a 10 year old FPGA... My other problem with FPGA's is that they mostly come in non-hobbyiest packages. Jos

Why? Although the manufacturers don't recomend it, I've had no problems removing and re-using SOICs, PLCCs, etc. I am sure most of us here would much rather repair a board of TTL than something based around essentially undocumented parts. That's one reason I stick to classic computers, of course. -tony

Tony Duell wrote: [...] The roadmap for that is already present here in Germany, and I think also in the US. This is IMHO driven by the request to close the "analogue gap" that still allows to make private copies without continuous cash flow. The market forces behind this will force us to throw away all our receivers without any shrug of their shoulders - besides, if you have to buy new equipment (and maybe even renew it/upgrade it every year, it will produce incredible revenues. Your maybe expensive B&O receiver set will become obsolete at a simple click of someone's fingers. One just has to sell the right trojan horse to the unwashed masses: "digital" is cool, is new, is great, and will give you much better sound or videos you ever even imagined in your dreams (there is some small drawback, but don't take it too serious)....it's absolutely great, isn't it? Do you really believe a newbie will be able in the beginning to select among Lattice, Mach, Altera, Xilinx, etc. programmable circuits where even the datasheet has to be read twice to understand whether this is a CPLD, EEPLD, FPLD, FPGA, with NOR/NAND/Antifuse program cells or external boot PROM, with almost uncomparable figures of the transistor equivalents, and whatever marketing invents in order to increase market share and to distiguish the basically same ideas? And then select the one circuit which has a cheap starter-kit, hopefully open-source tools for a not worse OS, and finally is not a dead horse that hasn't been delisted some time ago? Probably now, after MSEE degree and PhD, I would be able to find out after some time, but I won't expect the 13 year old boy (who built that TTL scrap computer 30 years ago) to come to a decision today. If I were to start now, I'd be not too different from the horde today - have my playstation or the pee-cee and would edonkey or kazaa MP3 files as everyone, eventually study for MBA, but surely not EE. It's so bad. :-( Holger

On Wed, 02 Nov 2005 18:33:11 +0100, woodelf <bfranchuk at jetnet.ab.ca> wrote: I have not done that after Intel announced the 4004, although it would be fun. By scratch I assume you mean designing the CPU, not using an existing processor. In this case I had the impression that the idea was to actually get something done, and a custom design seems a rather inefficient way to accomplish it. In any case, you would obviously have to port the OS as well, so it would not be "a computer which runs UNIX" as I understand it - until after the port was made. If I were to make a new computer design, I would in any case want to develop it together with a new operating system. UNIX has led to commodity systems at the cost of interesting design in my opinion. -- Using M2, Opera's revolutionary e-mail client: http://www.opera.com/m2/