On Thu, 10 Aug 2006, Don wrote: The no-stock-on-hand part got me confuzzled. What exactly does that mean? Wait a bit for it to get in stock or "who knows when they'll have it?"? The Magic-1 requires three 74F381s and two 74F382s. Grr! I just sent off an order to Digikey yesterday! -- David Griffith dgriffi at cs.csubak.edu A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?

On Thu, 10 Aug 2006, Don wrote: I used the online chat thingy hoping I could add some to my order and they told me that there's a few hundred or so minimum order on those. Luckily, the 84F381 is still available from JDR. -- David Griffith dgriffi at cs.csubak.edu A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?

On Thu, 10 Aug 2006, woodelf wrote: I sent in a note the Special Order People at JDR about that. I'll pass along what I learn as soon as I learn it. -- David Griffith dgriffi at cs.csubak.edu A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail?

Rumor has it that Holger Veit may have mentioned these words: I just checked - the F382 *is* in stock at Mouser Electronics, but it ain't cheap - $8.19 each in quantities less than 25. $6.83 for 25+. =-= At least I *assume* that's expensive. Maybe that's one helluva deal - I've never used these critters... =-= HTH, Roger "Merch" Merchberger -- Roger "Merch" Merchberger | A new truth in advertising slogan SysAdmin, Iceberg Computers | for MicroSoft: "We're not the oxy... zmerch at 30below.com | ...in oxymoron!"

"Roy J. Tellason" <rtellason at verizon.net> wrote: Well, they don't sell Digital Keyer kits like they did when they started! But you cannot fault Digikey because they don't stock every single obsolete part ever made. They are a catalog house, and if they don't always stock it then it gets ordered from the manufacturer, with typical lead times and often minimum orders. Just because you and me want good a MSI/VLSI F-series TTL part in DIP doesn't mean that anyone else in the world does! TI, Fairchild, etc. really do work to keep most TTL parts/variants orderable, and when they are then the catalog houses like Digikey, Mouser, etc. can get them for us. I have succesfully and happily ordered "not normally stocked" stuff Some of the other suppliers mentioned in this thread are surplus-only dealers, they might have a supply but when it's gone, then it's gone. Continually I see massive quantities of useful-to-classiccmper parts show up at auction houses or on E-bay. Things like quantity 20,000 ECL chips common to 70's or 80's superminis or minisupers, often qualified to meet a specific manufacturer's speed specs (I'm most familiar with the DEC variants). Even spread out among all of us with ECL-based PDP-10's, I don't think we need more than a fraction of those gigantic lots :-). Tim.

Chuck Guzis wrote: Yup, get ready to solder .2 mm balls on 800 balls BGA. Get your toaster-oven ready ;-)

The electronics hobbyist magazines of the 1980s, especially in their TV service columns, did not help the matter. Funny thing is that some of those same people moaned and griped when those fancy new printed circuit boards were coming out in the 1950s. -- Will

On Friday 11 August 2006 07:10 pm, Chuck Guzis wrote: Ok, you lost me there. I have no problem with the #14 bus wire or the slab of pine, but what's the beeswax 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 Friday 11 August 2006 07:00 pm, William Donzelli wrote: I don't remember seeing hardly any hobbyist magazines from the 1980s, most of when I read those was earlier on. But then I'd moved out and away from NYC where such stuff was easier to find to a much more rural situation, which probably has some bearing on it. Yeah, I couldn't use my 100/140W soldering gun on those nearly as often. :-) Actually I never had all that much of a problem dealing with boards, although the way that some of them are made seems to make them a bit more of a hassle to deal with. -- 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

William Donzelli wrote: s/to/too, duh. I really do know better. ;) Really?? That was before my time (born in '69)...I had no idea people whined about the advent of PCBs. -Dave -- Dave McGuire Cape Coral, FL

On Sat, 12 Aug 2006 22:34:21 -0400, William Donzelli wrote: THen there were those that that mounted vacum tubes on PCB's and the circuit heat of the tubes lifted traces over time. Not to mention carbon trails and arcing around load resistors mounted too close and cooked the boards. PSB's were not reliable untill the advent of transistors ! Bob

On Sunday 13 August 2006 08:48 am, Bob wrote: The tube sockets that mounted to a board with round pins (that were split in the middle) or with flat pins weren't too bad, but I remember encountering some stuff, one GE set in particularl stands out in my memory, where they'd actually put a hole in the board the diameter of the socket! That one had one or more sockets missing, along with several tubes missing. It amazed me that the owner actually considered it worth fixing when I came up with the estimate at the time... (1974!) -- 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 Sunday 13 August 2006 12:31 pm, Chuck Guzis wrote: One wonders why so darn much of the stuff I try to salvage parts out of has all of the pins bent over, which makes it *so* much more of a PITA... -- 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

Roy J. Tellason wrote: Good mangification solves that problem. I use an ancient but very effective Bausch & Lomb binocular 'scope with about 30x magnification. For larger stuff I use a boom-mounted magnifier with a circular fluorescent bulb around it. When I have more lab space (hopefully soon) I hope to set up a video magnification system, of the sort that vision-impaired people use for reading. That'll be a lot easier than bending over the microscope for hours at a time. Well again, like I said, it's *different*. Trying to apply the same techniques used for through-hole parts is the wrong approach. When I buy a bag of 0.1uF bypass capacitors in through-hole packages, for example, I open the bag and dump them in to the parts drawer. When I buy a reel of surface-mount 0.1uF capacitors though, I leave them on the reel and store the reels in much larger parts drawers. You remove the parts from the tape one at a time as you use them...at that level there's no need to look at the parts themselves to identify them. I started through-hole PCB soldering in the 1970s when I was a kid, and I was terrified to move into SMT stuff but I had no choice...Once I tried it I realized that it's really quite nice...faster, cleaner, and generally easier to work with if you have the right tools and IF you don't try to treat it as just a different kind of through-hole construction. Now, I do SMT pretty much every day. Do give it a chance Roy, you may actually come to love it as I have. -Dave -- Dave McGuire Cape Coral, FL

On Aug 12, 2006, at 4:40 PM, der Mouse wrote: "Build-only" designs? My past TWELVE designs were pure SMT except for connectors and some crystals. Each and every one was prototyped and debugged until working. The worst-case took ONE etch rev. Why? Because I pay attention to what I'm doing. See below. Yeah. You actually have to pay attention to what you're doing. What a concept. And when you screw up because you weren't paying attention, you actually need some troubleshooting skills. Wow, another neat concept! -Dave -- Dave McGuire Cape Coral, FL

On Friday 11 August 2006 23:32, der Mouse wrote: All you need is to use lots of flux and a chisel-tip soldering iron. With the correct technique (which is one of the few useful things I learned in my ECE classes), it's fairly easy to do. Basically, you tack down the corners of the chip, and then draw the chisel tip across the pins, along with the solder. Using plenty of flux is essential for this to work, and it'll probably take a couple of tries to get the technique down. Trying to solder the pins individually, and avoiding bridging them (like if you didn't use enough flux) is a complete pain in the ass, and just a bad idea. Passives are a bit trickier, but if you use a hemostat or pair of tweezers to hold onto it, that shouldn't be too difficult either (hint: tin the PCB pads first). Pat -- Purdue University ITAP/RCAC --- http://www.rcac.purdue.edu/ The Computer Refuge --- http://computer-refuge.org

der Mouse wrote: It is do-able; I remember hacking my DVD player to work with all regions, which required the addition of a couple of off-PCB surface mount chips. Soldering wires to the pins is a real pain in the butt, but it can be done. -- A. Because it destroys the natural flow of conversation. Q. What's wrong with top posting ?

Dave McGuire wrote: We'll be interested to see how your opinion changes when your eyes get 10 year older! ;-)

Chuck Guzis wrote: I'm lucky in that regard, as my hands seem to be steadier than most. But good tools can indeed address that problem. Manual pick & place tools are around, though a bit expensive...But I think such a thing would be pretty easy to construct in a workshop with minimal effort. Well with even high-end hot air systems showing up on eBay regularly for well under $100, why bother? -Dave -- Dave McGuire Cape Coral, FL

On 8/12/2006 at 12:57 PM Don wrote: I'dve thought that the lack of depth perception/stereo vision would get in the way. But then mine has never been very good. Even as a young man, I found it nearly impossible to position the two ends of a #20 platinum/platium-rhodium thermocouple wire for welding in an oxy-acetylene flame. Just couldn't make them line up. Cheers, Chuck

On 8/12/2006 at 2:04 PM Don wrote: In a steel mill? These were big 3- or 4-foot long Pt/Pt+10% Rh thermocouples. The wire was threaded through ceramic beats, then placed inside of a ceramic tube, then placed in a larger grey-black outer tube (SiC, maybe?). Used for temperature control in soaking-pit furnaces in the blooming mill. That particular summer taught me how much dry heat a human could take in short doses--the next year, a co-worker collapsed and died while changing a thermocouple. Anyway, the thermocouples got bumped during loading and unloading the furnaces and were broken pretty often. When repairing a thermocouple, on of the goals was to butt-weld any wire pieces together. A job that I couldn't do. Cheers, Chuck .

On 8/12/2006 at 3:02 PM Don wrote: I've been out of that area too long. This was when I was a YOUNG man. That was the day of mechanical chopper-stabilized vacuum-tube amplifiers, some running from 25 Hz mains power. Heck, some places back then still had key-wound chart recorders wtih clamp galvanometers. (Somehow, the word got out that the galvanometer supports were gold, so we'd usually have to come by a couple times a week and replace them). For some burner control, I do recall some optical quartz-lensed thermopile heads, but they weren't common. You checked accuracy of thermocouples with a hot-wire optical pyrometer and calibrated instruments with a potentiometer bridge and a thermometer (to measure the cold-junction temperature). Weston standard cells were still in use. Cheers, Chuck

Sridhar Ayengar wrote: Yeah, the last time I went in for an eye exam (driver's license?) I quickly memorized the third or fourth line on the eyechart and then took off my glasses BEFORE the examiner arrived (wanting to avoid a "visual" restriction on my license). What I hadn't realized -- but was SOON to do so! -- was that I couldn't read the *second* line on the chart without my glasses! <frown> I am a bit of a "fixture" in the neighborhood (often walking or doing yardwork or under the hood of my car, etc.). So, many of the neighbors recognize me when they bump into me at local stores, etc. Almost invariably, they will say "Hi" and then be disappointed that I don't recognize who *they* are. After a few seconds discussing this, I'll end up saying something like, "Oh! You're the blue, 1985 *mustang*" or "the beige minivan", etc. I wonder what they must think -- being known solely by the car they drive? :-/

Awee, thats nothing. I had a mobile SMP DECsystem-10 in my minivan once (two KS10s can actually fit in a Dodge Grand Caravan at once). Sorry, no pictures, though... -- Will

One was straight, the other a bit diagonal. -- Will

Dave McGuire wrote: You'll find that you'll have trouble each time you look away As you get older, your eyes' abilities to focus on as wide a range diminishes. And, the *rate* at which they focus decreases. Also, changes in light intensity seem to require a noticeable adjustment period (e.g., looking at a light emitting image vs. the ambient light on your worksurface, etc.) I've tried illuminated magnifiers, CCTV, a small rework microscope, etc. Each one reminds me that my eyes aren't what they used to be! It's not too bad if you stick to bigger SMT devices. But, when you've got *8* leads on a 1206 size package... :-( (e.g., the Leister will blow it clear across the room before you realize it!) Getting old is *such* fun! :-/

Chuck Guzis wrote: "I want to die in my sleep, like my Grandfather. Not SCREAMING like all the people on the bus he was driving..." Yeah, amazing how *suddenly* all the stuff your folks et al. told you "makes sense"! :-(

On Aug 12, 2006, at 4:48 PM, der Mouse wrote: Ok, you don't like surface mount technology. I get the point. Less common in the workshops of people who do nothing but through-hole assembly perhaps. As I said above...it's clear you don't like surface mount technology, and you're going to PICK PICK PICK at any positive thing anyone says about it, totally ignoring statements from people who actually have real-world experience with it. That sure is a nice attitude. Now I remember why I left this list a few years ago. -Dave -- Dave McGuire Cape Coral, FL

On Aug 14, 2006, at 12:54 AM, der Mouse wrote: The closest thing to an "electronics store" around here is Radio Shack. The stuff they sell is not, in my opinion, even suitable for through-hole work. As far as hardware stores...perhaps even less suitable than Radio Shack stuff. Perhaps. I just think it's quite silly to take the luddite attitude that surface mount is automatically evil because it's different from through-hole. I mean no offense here, but it's obvious that you've never worked with it. I don't know a single person who still hates it after having worked with it . I honestly mean no disrespect here. The whole "surface mount is hard" thing just grates on my nerves, because pretty much everyone who has actually done both surface mount and through-hole, myself included, thinks it's easier. -Dave -- Dave McGuire Cape Coral, FL

I just had a thought for ya'll (and I'm sorry for butting in like this)... but... ya'll are talking about using SMT chips to create homebrew CPU's. Many of the logic chips ye have been using do, indeed, come in SMT, SOIC type packages correct? Well... using ExpressPCB (the CAD program) I quickly rigged up a SOIC-8 (8 pin SOIC) to a 32 pin DIP package (4 SOIC-8 package on one chip). Below are some links. Anyway... using that kind of setup ya'll could make a PCB that fits into whatever package the original came in. Thus using the old computer with a brand new homebrew CPU. The ExpressPCB miniboard service will run ye 50-some bucks for a quantity of 3 boards (3 boards required)... but ye can fit 21 32 pin dip packages on those boards (7 per board). Thus making them easily profitable if ye should choose to sell them. BTW... when I rigged these pieces up I used a pin to pin connection. If I had the specs for the chips ya'll want to use... the I can easily rig up a similar adapter and (using a 4 layer PCB) connect all GND and VCC/VDD pins together... thus reducing the pin count and allowing more components to fit on the same board. Those who would like to see a certain chip(s) type put on a through-hole adapter... you are welcome to send me an email with the following info: Name: Email: Chip Package: Adapter Package: # of Layers (2 or 4): and attach PDF datasheets on all components if at all possible. Note: I will only draw the PCB... you are on your own ordering the boards. Note2: These boards will require cutting to separate the individual pieces. Note3: The '.zip' file I link to contains the '.pcb' drawing that is compatible with ExpressPCB Links: www.geocities.com/lyosnorezel/soicx4todip.bmp www.geocities.com/lyosnorezel/soicx4todip.jpg www.geocities.com/lyosnorezel/SOICx4toDIP.zip Good Luck! Lyos Gemini Norezel --------------------------------- Yahoo! Messenger with Voice. Make PC-to-Phone Calls to the US (and 30+ countries) for 2?/min or less.

Don wrote: But can you do POPCORN too. :) Still I would like to see in surface mount --- tiny Flip/Clips and see how small you can build a PDP-{Favorate number}.

From: "woodelf" <bfranchuk at jetnet.ab.ca> One thing that I think *would* be awesome in surface mount, would be to do a "scale model" based on the straight-8, with all those little SMT diodes and transistors, and no logic IC's at all (except possibly some SMT RAM to replace the core planes) :-). Vince (It might also be cool to make some of the diodes the glowing kind.)

On Sun, 13 Aug 2006, vrs wrote: That has been discussed before. It would be fun to do something like the PDP8-S on a single PCB with only resistors, capacitors, SOT-23 transistors and dual diodes (And yes LEDs in all the FF outputs would be nice). Peter Wallace

der Mouse wrote: Agreed. I regularly use 4-pack resistors that are half the size of the *body* of an 1/8W resistor. Without a good inspection magnifying glass (BTW, anyone have one to spare?), it's hard to tell if the component is even properly *aligned* before applying heat! Get yourself a Leister :> Then, mortgage your home to buy the infinite number of "tips" required :-/

On Friday 11 August 2006 04:37 pm, Tim Shoppa wrote: No, probably not, but sometimes those parts can be useful in other contexts too, like radio ferinstance. There seems to be a bunch of ECL parts used as prescalers, that I've noticed. And even some ECG/TTL hybrid parts, which I'd never seen before. -- 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