I also think it is in the spirit of the computer - using what is available to fix a problem at hand. I think the arduino was overkill when an attiny (smaller, easier to hide) would probably serve just as well. If you have the ttl logic bits lying around and know how to use them, fine. Still would probably need debugging. On Jun 14, 2015 2:41 PM, "Simon Claessen" <simski at dds.nl> wrote:

On Mon, Jun 15, 2015 at 11:52:28AM +0200, Johnny Billquist wrote: Speaking for myself, yes. I have a Teensy 2.0 lying at my desk, it's Arduino compatible. I have the development environemnt set up, a small solderless breadboard and proper power supply. I could probably whip up the C-code for a flicking pin on and off in the correct pace in very little time. Now, if the alternative is reading up on crystals, oscillators, dividers and related support chips, figure out where to buy and then wait for the parts to ship, which option do you think I will choose? Of course, I think it's overkill and anachronistic and I'd rather use the Teensy for something else, so I'd probably read up and do it "right" too. /P

Unfortunately I believe you. Use at least a thousand times more components than you need to. In general this worries me if you are restoring a vintage minicomputer. How on earth can you hope to fix a TTL-built CPU without knowing the common TTL chips and without having a few on-hand? -tony

LOL! I must admit that I used to scorn those durned kids using Arduinos to do the job of a 555. But then I pulled my head out of my ass and realized that times change, nowadays a microcontroller is as cheap and common component as a 555 was when I was a snotty kid, and the new-fangled "maker" movement with its Arduinos and serial-controlled addressable LEDs and conductive thread is keeping younger people designing things and making them instead of just being dumb consumers. It's all good stuff! And once I got a better idea of how much it costs to keep an engineer breathing for an hour, I also realized that it often makes more sense to overkill the heck out of a task with a $20 micro board than it would to spend even a half hour longer doing it the "right" way. -- Mark J. Blair, NF6X <nf6x at nf6x.net> http://www.nf6x.net/

I had that same mental hangup when thinking about how I might design an SD card based TU58 emulator in the same form factor as a TU58 cartridge (still on my to-do list, by the way). How was I going to implement the user interface? It's not like there's much room for an LCD or buttons on the edge of a TU58 cartridge. Then it finally hit me: SD cards are cheaper than TU58 cartridges ever were. So why not just use the first 256k, ignore the rest of the card, and swap cards exactly the way one would swap TU58 cartridges, with one image on each card? Yeah, 99% of the card is "wasted", but they're presently cheap and plentiful enough to ignore that. Ok, I might actually have the emulator read a file from a DOS filesystem rather than using the first 256k of raw blocks. But it'll probably just be a fixed filename with no controls to select a different one, and the expectation that an entire (cheap, plentiful) SD card will be devoted to each tape image. At least this way, other things can also be on the card, so it doesn't need to be wasted if not needed. Your friend should understand that the larger card that he would be "wasting" probably has less silicon in it than the older one with less capacity. The cheapest card that is reliable, fast enough and large enough for his task is the best one to get, even if it's much larger than he needs. Just one of the weird parts of the Moore's Law curve! Hmm, this reminds me that back in the day, floppy disks were expensive. We have it easy with cheap and plentiful SD cards nowadays. But maybe my perspective is different as an employed adult rather than a teenager with limited funds? Anyway, SD cards seem to be cheap enough to be nearly disposable nowadays. -- Mark J. Blair, NF6X <nf6x at nf6x.net> http://www.nf6x.net/

I am of course counting all the transistors inside that chip. My father was a chemist. He knew enough electronics to teach me things like ohm's law, but certainly not digital electronics. And I have never done any classes in electronics. I learnt by : 1) Reading every darn book I could find on electronics from the 1920s onwards 2) Experimenting. Soldering up circuits and finding out why they didn't work. Some of the better educational kits like the Philips EE series helped in my younger days, but alas you won't find those now. 3)Getting a minicomputer and investigating it. That means reading the printset, cliping on a logic analyser, etc. As am I. I've learnt a heck of a lot since I started (there is a common myth that there is something magic about a processor. This hobby has taught me to understand quite a few at the gate level). And the day I stop learning is the day I am in a pine box. As an aside, I am not overly enamoured by the RPi. I think there are possibly better alternatives like the Beagleboards (?) which I need to investigte. This is one of my main dislikes with USB. It is so complicated that you have to use a microcontroller. Unlike any of the more sane interfaces that you can implement with simple logic if you want to. -tony

Err, yes... It is impossible to understand the transistor using classical physics.... People have made transistors at home, even made their own semiconductors (copper oxide) to do this, but they are not good ones. 'Instruments of Amplification' is a fun book on this. Even though there are at least 4 different USB connectors.... IMHO USB got round the problem of null-modem cables by making them impossible. Which to me is not an improvement. I guess USB is OK when it works (like plugging in a memory stick) but a right pain to debug when it doesn't. And having read the standard there is much I dislike about it. -tony

On Monday (06/15/2015 at 10:14PM -0700), Mark J. Blair wrote: I'm going straight to hell because I recently participated in a customer design where they wanted to change the USB function on a device we designed for them from host mode to device mode but they didn't want to change the connector on the box. So, now you have to use a Type A to Type A cable to connect this box to your computer. That is just really, really messed up and I honestly tried to make it right but it was like pushing a rope. I hope my friends will visit me in prison. Chris -- Chris Elmquist

On Tuesday (06/16/2015 at 07:43AM -0700), Mark J. Blair wrote: well, you know, it's a different world these days. You go to these places down dark alleys, surrounded by shady characters and you can buy them. -- Chris Elmquist

On Tue, 16 Jun 2015, tony duell wrote: The spec forbids extending the cable further? Or should the spec forbid absolutely any cable, with absolutely any USB connector on either end?

On 2015-06-16 1:14 AM, Mark J. Blair wrote: in my opinion, Windows' implementation of USB is fundamentally broken. It's a mouse, you stupid computer! You shouldn't need to spend a minute or more installing a new device driver for it! And you shouldn't need to install the driver yet again if I poke it in a different hole than I did last time! Every other ******* OS on the planet is smart enough to say "Oh, a mouse! I know how to use those!" within a handful of milliseconds! Here's a cute gotcha I hit this week: - Have a running Windows 8.1 machine with PS/2 keyboard. - Shut it down, start up with only USB keyboard. - Shut down and boot again with PS/2 keyboard atached. - Windows ignores it (although BIOS flashes lights normally, etc). - Registry change (found by google) & reboot brings it back to life. Can't imagine how many good keyboards were dumpster'd over that one. --Toby

On Tue, Jun 16, 2015 at 04:28:16AM +0000, tony duell wrote: Well, that was obvious. But it raises an interesting point, today you can cram a whole computer in the footprint of the simplest DIP carrier. For the same price point and same reliablity. Is it then overkill if you choose to use thousands of those transistor over using just 10 ? Similar to Mark's example of using just the first bytes of an SD card with gigabytes of storage. I completely agree, I detest USB for various reasons. However consider this: As I said, I have used the Teensy to interface an old 11/70 front panel with simh. One possibility I've considered is to let the Teensy present itself as USB mass storage when first attached to a PC. On this mass storage I would put a special version of simh and 11/70 system images. When this version of simh is run, it will instruct the Teensy to present itself as the front panel interface instead. So, I can bring my 11/70 front panel to any friend with a suitable computer and show him/her the ropes :) Admittedly, the Teensy doesn't have enough storage for this, but it shows the flexibilty of USB coupled with a microcontroller. /P

I think that paper tape, used outdoors on a rainy day, is likely to be more reliable than a real TU58 tape. :) -- Mark J. Blair, NF6X <nf6x at nf6x.net> http://www.nf6x.net/

You got a thumbs-up! (In Brazil we call it "Joinha") :)

I don't think it is over kill. If you want over kill try this:- https://www.youtube.com/watch?v=ALXax3Gydl8 and FPGA implementation of the Baby or SSEM which had 32x32 bits of RAM. The implementation uses around 1% of the Spartan 3E 1200K gates, and that includes the logic to generate the VGA which is around 50% of the circuit. I expect to get it on a 100K gate chip but that?s still over-kill. I am also aware how HARD baud rate generator chips are. Firstly you need to know the multiplier, and then you need a crystal that can easily be divided. I looked on E-Bay UK and the cheapest dedicated baud rate generator was 10x the price of a Arduino Nano. Then I would need a crystal and the other bits to make the generator. I would expect the chip count on a dedicated baud rate generator board to exceed that of the Nano. Of course it is not original, but an authentic board would only use SSI TTL and where would one find that easily. I personally think it is an appropriate cludge that allows de-bugging to continue and gives you time to work out what the best long term solution would be. Dave

On 6/15/2015 9:08 AM, Toby Thain wrote: But alas the software does *not* support the older chips. You want to make a mod 5 years down the road, sorry we do not support that model any more. TTL needs to be stock piled now for the next +50 years. I finally got 18 bit FPGA computer (DE1) design I like, that is early 70's speed. 1.5 us core. What I am having problems is finding a good book on Operating Systems from that Era that is online, any one know a good book? I have software that I need to write. Ben.

How old is old? I managed to get a copy of ISE10.1 downloaded, installed and running without phoning, ringing or otherwise jumping through hoops. That supports the Spartan 2 which has been obsolete for some time.. If you want to play with some Spartan 2 chips contact me off-line.

What?s ADHL? I know VHDL and haven?t yet learned Verilog. I once used an old proprietary CPLD language with Lattice (Lattice-HDL???). Very primitive and not particularly easy to use, not to mention too limited for anything beyond little CPLDs. VHDL and Verilog have the benefit of being standards, and at least for VHDL there are open source tools available (ghdl) that work well. paul

On 2015-06-15 12:57 PM, Dave G4UGM wrote: Altera has the old version of Quartus for download on their site. I had to take advantage of this to get a version that would compile for my Cyclone I. :) Anyone with older chips might want to grab the appropriate versions while they are still there... --Toby

I thought I'd take a quick spin through the operating systems section of my library now that I'm at home just to give you some titles that you might want to check out. 1. Toby mentions Tanenbaum's Minix book and that's a fairly canonical text ... there is a lot of great information in there but IMO some parts can be a little opaque and overly verbose ... it can be nice to have some supplementary sources; see (2) :O 2. For more illumination on UNIX, I find both Maurice Bach's Design of the UNIX Operating System and McKusick's 4.4 BSD book to be well-written. 3. There's a design example (source with walkthrough) for a simple task scheduler for the PDP-11 in Eckhouse's Minicomputer Systems: Organization and Programming (PDP-11 edition). 4. Madnick/Donovan Operating Systems or Donovan's Systems Programming ... were, I imagine, the canon of the 70s and early 80s ... these are written mostly with the S/360 in mind ... 5. For something maybe less academic and a bit more practical, look for the "MMURTL book"; I believe the title is "Developing your own 32-bit Operating System" by Burgess ... neat book ... I've leafed through it but I down own a copy. Platform is i386. 6. There are also a lot of practicals on Merrill Press that are very good i.e. The 68000 Micrporocessor by Antonakos ... that will demonstrate the implementation of a basic ROM monitor from scratch ... I found these books very illuminating and I think they can be a good bridge between the more theoretical treatment given in a lot of textbooks and the actual nitty-gritty of writing some code on bare-metal hardware. You can pick up a used copy of any of these books for a buck or two on the used market; that's hard to beat. That's pretty much all I got ... always looking for interesting books on this topic contemporary or historic; if anyone else has titles to share that they could recommend, I'm always happy to hear. Best, Sean On Mon, Jun 15, 2015 at 6:42 PM, Toby Thain <toby at telegraphics.com.au> wrote:

If you?re looking at 1960s designs, you should be fine even if the machine had wider words. By the standards of that era, any modern computer (probably including the one in your microwave oven) is *large*. For example, the THE OS memory footprint is about 16k words (48k bytes), and that includes not just what we think of as a kernel but also all the device drivers and a bunch of language support library code. Other designs from that era are smaller still. paul

If it?s written with 360 operating systems in mind, I?d steer clear. I don?t know of much in the way of valuable OS design principles to be found there (except perhaps the lessons reported in ?the mythical man month? or in Tom Watson?s famous anecdote about the size of the CDC 6600 development effort). paul

On 2015-06-15 8:09 PM, ben wrote: I figured, although I haven't seen it. My copy is 1987. Glad I could help. --Toby

On 2015-06-15 9:11 PM, Paul Koning wrote: Another essential read in this vein is "Classic Operating Systems" by Per Brinch Hansen[1], which is really an anthology of papers & satisfyingly meaty. Perhaps like me you will be left feeling that we were so much better at this stuff 40 years ago. Also that many "modern" operating system ideas were invented much earlier than we might be tempted to think. (Multics is the usually cited case, but this book has dozens of other examples.) --Toby [1] http://www.amazon.ca/dp/038795113X

German? With an English title, I'd guess it'd be in English, and IIRC the E in THE stands for Eindhoven, which I'm pretty sure is in the Netherlands, so my guess would be, if not English, then Dutch.... /~\ The ASCII Mouse \ / Ribbon Campaign X Against HTML mouse at rodents-montreal.org / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B

On 2015-06-15 9:55 PM, Toby Thain wrote: It's also one of the papers in the Brinch Hansen book cited earlier in the thread. (Google books: http://ur1.ca/mu61v ) --Toby

On 6/15/2015 7:55 PM, Toby Thain wrote: I saw that paper before. Ben.

I've jsut turned up the M452 schematic. Has anyone else looked at it? It's a <expletive> RC transistorised oscillator driving a /4 divider chain. Are you seriously telling me you don't have a junk box full of random R's and C's and you can't change the timing components to get whatever rate you want out of it? I am very worried that people would rather use a microcontroller than change a couple of passives. Can't anyone read a schematic and think???? -tony

Err, to blink a neon glow lamp you use _one_ resistor and _one_ capacitor and make use of the difference between striking and maintaining voltages. But that is not the point. The original design for this M452 baud rate clock is an RC oscillator. One that can run at any reasonable frequency. When restoring a machine you should keep as much of the original design as possible. If you want to do a reversable change you should still change as little as possible. Since it appears you can change the buad rate just by changing a couple of passive components that's what IMHO you should do. -tony

Well it had better not. I don't have one Oh come on. You yourself said you are here to learn. This module is hardly complicatated. OK, it is not obvious what some of the waveforms are (which is a good reason to put that board on the bench -- it will run on its own -- and probe it with a 'scope. Being an oscillator, all the waveforms are repetitive so _any_ 'scope will do), but it is farily clear that it is an RC oscillator and that the time constant of a particular RC network is going to have an effect on the output frequency. So you change the capacitor and probe with the 'scope again. And so on. -tony /P

Would you put plastic handles on a piecc of antique furniture? Would you make the seatboard for an antique longcase clock from MDF? Both are easily reversable, BTW. FWIW I have made programmable dividers on a couple of occasions recently (one was a 100/120 flash-per-second stroboscope, the other was the transmitter half of a modem to talk to TDDs). Both of them worked first time. I guess it's just what I am used to. -tony

Ah, 'there's not the time to do it properly, but there is the time to do it again'. Why not do it properly first time? What is the rush in bringing up a classic computer? And for a test, use the TTL pulse generator you have on your bench. Or even an NE555 astable (yes, with a decent capacitor it is stable enough for a baud rate generator, I've used it). Heck, I've worked on machines that used a 2 transistor astable multivibrator for the baud clock. Surely you have 2N3904s in the spares box? Incidentally, if certain horologists heard you would use MDF in an antique clock, you would be going home with a pendulum rod shoved where the sun don't shine ;-) 'Full stock of TTL parts' ??? You make it sound like I am suggesting using lookahead carry generators, parallel multipliers, Excess 3 to 1-of-n decoders and the like (all of which exist(ed) in TTL). No, I am suggesting using some very common counter and gate ICs. How are you going to fix a TTL-based machine like your 11/730 without spares and without knowing what the ICs do? It is cheating :-) More seriously, tools are one thing. And had it been suggested that as a quick fix you took the TTL output reasonable (even if said sig-gen contained many times the number of components of the rest of the machine). But to make a custom solution that is over-complicated IMHO is the wrong way to do it. You might well inject your HP sig-gen into the mixer (first detector) stage of your WW2 radio to get it going if the local oscillator had failed, or if you didn't have the right crystal, or whatever. But I hope you wouldn't replace the valve (tube) based local oscillator in such a set with a digital synthesiser as a permanent 'repair' -tony

And you don't have any NPN transistors around? With one you could buffer the output of your sig-gen to TTL levels. Amazing.... Those are about the most common components around. I think I buy 2N3904s in lots of 1000, I use so many of them [...] FWIW I do have Bristol spline keys here. Needs for working on IBM and Friden machines for a start. FWIW, this is not the miltary or firearms list, so I wouldn't expect people to necessarily have the equipment and spares for such things (if you do, fine). It is the classiccmp list, where some people, including your good self restore the actual old machines. And yes, I think it is is reasonable to assume they will have access to common (very common) electronic components. -tony

On Mon, Jun 15, 2015 at 04:53:01PM +0000, tony duell wrote: No but I would put an electric heater in a steam engine if it meant restoration would progress faster. (yes, feel free to lecture me how big that heater would have to be...) /P

On Mon, Jun 15, 2015 at 01:59:11PM -0700, Mark J. Blair wrote: So far I feel we've been civil :) I too hope I'm not coming of to harsch.. I feel a bit cranky because its 25 degrees celsius in my workshop :/ Speaking of steam engines and boilers. I saw a 1918 Bucyrus steam shovel this weekend. Mostly rust, but under slooow restoration. /P

I think we're doing ok. The same folks having a spirited debate in this thread are carrying on just fine together in other threads at the same time, so I don't think the fangs are being exposed. :) -- Mark J. Blair, NF6X <nf6x at nf6x.net> http://www.nf6x.net/

On 17 June 2015 at 05:09, Huw Davies <huw.davies at kerberos.davies.net.au> wrote: Off topic for a moment but, do you know perchance what's going to happen to XH558 at the end of this year? I've never had a chance to see a flying Vulcan, and it's too bad I won't ever get to see one (nor did I get to see the awesome display of both of he flight worthy Lancasters flying together last year...). The point you raise is comparable to the fact that we'vve basically flown the life out of the last Avro Vulcan, meanwhile here in my home town we're still managing to keep an Avro Lancaster flying after all these years. Also, I realize anyone can infer where I live based on the statements in this e-mail, hah. Cheers, Christian -- Christian M. Gauger-Cosgrove STCKON08DS0 Contact information available upon request.

On 17/06/2015 12:16, Christian Gauger-Cosgrove wrote: I'd have directed you to http://www.vulcantothesky.org/ if Rob hadn't already. Sometimes, though, it flies near places not on the official list - for example, I've seen it fly almost over our house (we live near Elvington) on two different Fridays in the last month or so. Presumably in transit to some other show. Sadly, on the first occasion it flew circuits for a quarter of an hour, but I didn't hear it (or realise it was the Vulcan) until my wife said something like "Oh, that triangular aircraft has been flying around a bit for a while." (We often get noise from Elvington and sometimes I tune it out.) I watched it fly a couple of circuits before I thought to fetch the camera - by which time it was almost out of sight. On the second occasion it was so cloudy I couldn't get a decent shot. Sigh. -- Pete Pete Turnbull

Hi Christian, I'm guessing by the CLLI code in your sig, you're maybe close to St. Catharines, ON, CA? If that's true, I just wanted to let you know that - IIRC - there is a SR-71 on static display within a car trip of your location in Kalamazoo, MI at the Kalamazoo Air Zoo. It's actually a B-model ... trainer ... I saw it a few years ago when I was in town visiting my parents and it was pretty cool ... I think it's still there: http://www.airzoo.org/page.php?page_id=192 It doesn't do flying demos but it is a complete aircraft in "mint" condition and you can get right up there and touch it. Best, Sean On Thu, Jun 18, 2015 at 9:58 AM, Christian Gauger-Cosgrove < captainkirk359 at gmail.com> wrote:

----- Original Message ----- From: "Christian Gauger-Cosgrove" <captainkirk359 at gmail.com> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Sent: Thursday, June 18, 2015 9:58 AM Subject: XH558 - was Re: using new technology etc ----- Reply ----- As a matter of fact, both the Vulcan and the Blackbird have appeared at the Canadian International Air Show here in Toronto in past years: https://en.wikipedia.org/wiki/Canadian_International_Air_Show Saw them both; Awesome! m

I worked on the cameras on the SR-71 at Beale in the late 1980s. Still gives me goosebumps thinking about it. The drone was the D-21 which flew on the back of the M-21 (which was modified A-12 (which itself was the SR-71s predecessor)). You can see a video of that fateful test here. https://youtu.be/GMyC2urCl_4

Yes, you never got tired of seeing a ?sled? (our nickname for the blackbird) take off. Even more impressive were the engine tests of the J-58 where they used to invite us to come watch at night. You were able to stand within 50 feet or so of the engine which was locked down into a test harness as they ran it at full afterburner. The ground would shake and your teeth would rattle as your ear protectors tried to bounce off your head. I?m sure the tinnitus I have today was caused by those experiences.

On Mon, Jun 15, 2015 at 10:53:33PM +0200, Pontus Pihlgren wrote: That has been done before for production purposes. I kid you not. Happened in Switzerland during WW2. Due to the war, coal was a bit in short supply, but Switzerland already back then had plenty of (hydro-) electric power, including on the railway grid. So they converted a few steam locomotives to steam-electric by replacing the firebox with electric heaters. IIRC it was only a few locomotives and they were mostly used for shunting work. Kind regards, Alex. -- "Opportunity is missed by most people because it is dressed in overalls and looks like work." -- Thomas A. Edison

On Thu, Jun 18, 2015 at 08:25:46AM +0200, Pontus Pihlgren wrote: It looks suspiciously like a compressed air hookup. The fact that there is no visible steam "escaping" just reinforces that impression. Kind regards, Alex. -- "Opportunity is missed by most people because it is dressed in overalls and looks like work." -- Thomas A. Edison

On 06/14/2015 12:41 PM, Simon Claessen wrote: I'm a bit more pragmatic. Whatever it takes to get something running, I'll do it. For me, that's the entire point of having the old stuff around. Otherwise, a non-working box is scarcely better than any other piece of antique e-waste. If there's an accurate emulation available on modern hardware, I'll use that rather than play with some old, cranky piece of iron. Others may certainly have different opinions. --Chuck