Richard wrote: Cheater -- I used real cards only to have them fall. Well you can't say you don't learn things here or from other internet sites. I downloaded some motorola application notes from bitsavers. Wow they sure had a lot of different types of TTL. I wonder how only the 74xx became the only TTL used today?

On Sunday 18 December 2005 03:22 am, Chuck Guzis wrote: I read somewhere recently (another list) where Fairchild had their own proprietary numbers out before that, 8xxx or 9xxx or something? And then there's DTL, I have *no* idea how those are numbered. For a chart that may be of some use (and which is continually being updated), have a look at http://yourpage.blazenet.net/rtellason/parts.html and the "by-generic-number" chart in particular. Hey, I guess this is my first post to this list -- I've been hooked in for a week or two more or less. I thought that I was way ahead of a lot of the folks I encounter in other contexts with regard to older hardware, but some of you folks just blow me away! Got lots of old machines, my first being an Osborne Executive with an external "Design One" hard drive box, WD1000 controller card in there that I hope still works, that one used to support George Peace's old RCPM system but with a different HD in it where the bearings went bad. Making that work with an ST225 was fun, and I never did get the write precomp part of it figured out so the last few MB of that drive are pretty much unusable. Got a number of Kaypros, maybe six or so. A Cromemco System Three w/ terminal that has some sort of drive problem -- they used incandescent bulbs in there for the indes sensors and whatnot, didn't they? A vic20 and c64 or three, plus a couple of 1541s and a whole mess of parts for them, I used to make a half-decent living fixing those, so if anybody needs parts give me a holler. Got a Televideo 816, which has the only 8" belt-driven HD I've ever seen, though it's unfortunate that the interfaces aren't rs232 or something more usable than what's there. Got a Bigboard II that I built, but have no BIOS or system disks for it. There's probably some other stuff I'm forgetting, but I may remember in subsequent posts. I'll no doubt run across some things from time to time that I want to get rid of. Like that Televideo for example, I don't see that as being all that terribly likely to be useful. Or the couple of Token-Ring cards I have at hand here -- anybody want those? I'll post about some other stuff as I come across it or think of it... Lots of stuff in here I'm seeing mention of that I haven't thought of or done anything with in ages. One hell of a list, if I can keep up with it! :-D -- 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 12/18/2005 at 11:03 PM ard at p850ug1.demon.co.uk wrote: ...and then there are parts like the 74L85/74C85 with wildly different pinouts from the 85, LS85, ALS85, HCT85, etc... Another thing to be aware of is that while pinouts may be the same for parts, functionality may be quite different. Case in point: the pedestrial 74107 JK FF; the 74107 is level-triggered; the LS107is edge-triggered. It can make a big difference in some applications. Cheers, Chuck

Scott Stevens <chenmel at earthlink.net> wrote: Wow, it's pretty hard to meet the demand of "ALL". The various TTL handbooks from TI/Motorola/National/etc. do a halfway decent job of describing their silicon processes (not always identical from manufacturer to manufacturer, even with the same part numbers) at least at the "why you should use our brand of chips" level. Probably very insufficient in terms of building your own fab line. Many of these older handbooks are online at Bitsavers. These details are conspicuously absent The Motorola TTL and CMOS books from the 70's are particularly good at giving you a snapshot of the silicon and showing you parasitic structures in schematics. The TTL/74x handbooks also do a pretty good job of external electrical parameters as a function of family, as do Lancaster's TTL cookbook (mid 70's) and Horowitz&Hill (early 90's so many CMOS parameters too.). But when I have to keep up with the 3.3V-and-lower-tiny-fast-bus-driver 74x parts I pretty much have to start from scratch with electrical parameters, I can't keep them straight anymore. I suspect that you're asking about enough detail to lay out your own silicon and start your own fab line, and I don't think I've ever seen anything that'd teach you how to do that. The EE texts I've seen on this subject tend to concentrate almost exclusively on VLSI and NMOS/CMOS processes. The 70's-era TTL/Moto/National handbooks do have many transistor-level diagrams with resistor values (especially for simple gates and some of the more complex flip-flops), combined with some guesses at transistor parameters these can be used to build not-so-bad SPICE models, if that's where you want to go. Sometimes they even include the parasitic structures in their schematics. Tim.

I was talking with a fellow who worked for a local pipe organ builder (now retired) about their needs for logic in the adjustable combination actions of their instruments. For non-organists, this basically is the mechanism that allows a player to set combination of stops so that they are actuated by depressing a button or a toe stud. Basically a memory with a bit of control logic driving some actuators connected to the drawknobs. Given that we still have instruments around that were built in the 13th century, I asked the guy what they did about making sure that there was a 100-200 year supply of replacement ICs. IIRC, they used mostly 74LS TTL and some CMOS and a bunch of power Darlingtons,etc. (a bit more about that later). He replied that they make up a care kit with 2 of everything and place it safely away inside the console. I opined that this hardly seemed like enough. He said that the function was simple enough that the kit was mostly to get one past minor repairs; they expected that periodic redesigns would be routlinely undertaken with the appropriate modern logic. BTW, the power components are mostly for visual effect. He said that if a tracker action instrument (which is what they made) was being installed, organists demanded drawknobs that moved and not simple buttons, which would be far easier to accomodate. Go figure. A couple of years ago, I was reading about the lock controls on the Panama Canal and, at least until a few years ago, they're still original equipment installed in the 1910's, all that nice brass and mahogany stuff. I read that a microprocessor-based system is slated to replace the old circuitry; anyone want to guess if it'll still be intact 90 years after installation? Cheers, Chuck

Not quite the same thing, but 2 monitors I have here (one a Barco colour monitor, the other an HP X-Y display) have extender boards stored inside to make it easy to work on the plug-in PCBs. I recently bought a second-hand Philips 'upright' reel-to-reel tape recorder, and found a schematic glued to the inside of the case. At one time this was quite common on consumer electronic devices I believe. -tony

On Mon, 19 Dec 2005 17:56:55 -0800 "Chuck Guzis" <cclist at sydex.com> wrote: I was disappointed when the XT-clone motherboard vendors stopped including the schematic diagram in that little user guide that always comes with a motherboard. I have kept all the user guides I've had that included the schematic. And the shocking thing is it's always the same schematic. You can use that schematic to troubleshoot almost ANY XT clone motherboard placed on the board identically. That was the era when IBM lost control of the design of the 'IBM PC,' and had to 'invoke the PS/2' to try to grab back control of the market.

Actuallym this tape recorder uses (germanium) transistors. I'm still looking for the mains-powered valved version (EL3514). But yes, certainly a lot of valve radios, etc, had a schematic inside Yes, and most of them were very close to the schematics in the IBM TechRefs :-) -tony

"lot of different types" is exactly why. This "thinning" has happened with almost all logic families, but there are always exceptions - until about 10 years ago there were a couple of Motorola 4000 series TTL (!) parts still in use, as well as some Motorola 1600 series MECL III still useful. William Donzelli aw288 at osfn.org

woodelf wrote: I remember as a child using hundreds of used IBM *punch* cards to build towers. The quantity made it feasible to build quite large and high structures. And of course, seeing how many you could pull out from the bottom before it collapsed. Or building domino-like trails of them and then starting them falling over. A quantity of punch cards was a great children's toy, in the same vein as "the cardboard box being a better toy than what came in it".