Christian Corti wrote: I like the Tek 465 much better than the 555. And I like the 2245/46/47 even better. But I don't think there's any model that qualifies as "best scope ever made", for the same reason that there isn't any "best car ever made": the category is too broad, and different models are better for meeting different requirements.

On 08/17/2012 05:38 AM, Christian Corti wrote: Sadly I lack a power umbilical for my 555, but I hope to get it running someday. Have you seen the 453? Sharpest CRT I've ever seen on any scope from any manufacturer. NOT the 453A, but the original 453 with the Nuvistor input stage. The (larger) 453A CRT is nowhere near as sharp as that of the 453. That scope is a real pleasure to use. -Dave -- Dave McGuire, AK4HZ New Kensington, PA

On 8/16/12 2:28 PM, "Eric Smith" <eric at brouhaha.com> wrote: I have to share/boast: I have a (working) Tek 561A and just acquired all the *original* manuals. I have the manuals for the scope itself, the 2B67 time base, and the 3A74 and 3A75 plug-ins. I'm such a geek. -- Ian

Christian Corti <cc at informatik.uni-stuttgart.de> wrote: Is it so hard to just read the article?

On Fri, 17 Aug 2012, Oliver Lehmann wrote: On this machine, Yes. It shouldn't be so hard, with XP and a Winmodem, but it'll be a few days before I can get back to a decent connectin.

On Aug 17, 2012, at 12:40 PM, Chuck Guzis wrote: I'd really prefer a stack of 80-column cards, please. My tape drive is on the fritz. - Dave

On 17 Aug 2012 at 15:09, Fred Cisin wrote: If you need one, I can send you a USR Courier V.Everything. You do need a real serial port for it though. --Chuck

On Fri, 17 Aug 2012, Fred Cisin wrote: I've had extremely good results with some of the USB 'adapters' (true serial ports with a USB interface, basically) that use the FTDI FT232B chip. They even have board designs and the driver source code available if you want to build it yourself. http://www.ftdichip.com/Products/ICs/FT232B.htm I have have replace some Sipex SP213EHCA RS232 transceiver chips in several of these devices with Maxim MAX213EAI parts. The Sipex transceivers are supposedly rated for +-15KV ESD, but my experience with them seems to indicate that they really aren't worth squat. On the other hand, the pin and function compatible replacement parts from Maxim are still working flawlessly. To me at least, the Sipex part looks to be a cheap knock-off of the Maxim part. As far as modems go, MultiTech and the USR Courier are two of the best. I'm not sure which MultiTech models support which DTE data rates, but with the Courier modems, if you have a 25MHz model, you can drive them at 230400 baud DTE, which came in handy if you are using V.90 and hardware data compression. I used them with Digi serial hardware to get those speeds. Before I had broadband, I used two of those modems paralleled up. Some of the late model USR Sportster modems can also be flash upgraded, but unlike with the free updates for the Courier modems, USR thought they could turn the less expensive Sportsters into a cash cow and didn't make the upgrades freely available (inkjet printer syndrome), with the sole exception of the modems sold with the X2 firmware already in them. That said, if you knew what you were doing, you could flash upgrade the late model 33.6 modems that had flash memory chips in them with the very same V.90 firmware that the X2 modems could use. It has been a very very long time since I did any tinkering with Courier and Sportster modems, but just last week I ran across my files for these, including the firmware updates and the 'unofficial' update utilities for the Sportster modems. As a side note with the USR Courier modems...when the electrolytic capacitors used in the power supply section of these modems begin to age (they get hot in normal use since the modems don't have forced air cooling), the modems will begin to emit digital "noise" (hissing/buzzing) via the internal speaker. There are no form-fit replacements for those capacitors, but I did find some which can be turned sideways that fit and work perfectly. The replacements probably have a longer life, too, since they aren't size-reduced and limited in height. If someone needs this information, I can dig through my notes for the part numbers.

On 17 Aug 2012 at 16:25, Fred Cisin wrote: It might--I use one as a convenient connection to debugging projects that use RS232 for output. I don't know how well they work with hardware (RTS/CTS) handshaking, however. I got rid of the Sportsters that I had--worthless pieces of garbage. One common problem was overheating. I still have the original HST Dual Standard that I started with--it works fine. I've got a Courier V.34 that's been upgraded as well as the V.Everything. I also have a Zoom 56K and a Hayes Optima "business modem" that I think tops out at 33.6K (Hayes promised upgrades to 56K, but realized that they couldn't do it without swapping the entire modem. They were in Chapter 11 at the time and simply weaseled out of the promise). It was right around then that consumer-level modems started to get really trashy. I have no idea why I'm hanging on to these things. --Chuck

On Fri, 17 Aug 2012, Fred Cisin wrote: Yes. Find one that uses the FTDI 232 chip. They're very good. g. -- Proud owner of F-15C 80-0007 http://www.f15sim.com - The only one of its kind. http://www.diy-cockpits.org/coll - Go Collimated or Go Home. Some people collect things for a hobby. Geeks collect hobbies. ScarletDME - The red hot Data Management Environment A Multi-Value database for the masses, not the classes. http://www.scarletdme.org - Get it _today_! Buying desktop hardware and installing a server OS doesn't make a server-class system any more than sitting in a puddle makes you a duck. [Cipher in a.s.r]

On Fri, 17 Aug 2012, Fred Cisin wrote: Fred, have you thought of finding a USR 56k External? eBay has some Couriers for not a whole lot (but there are some that are just insanely priced!) g. -- Proud owner of F-15C 80-0007 http://www.f15sim.com - The only one of its kind. http://www.diy-cockpits.org/coll - Go Collimated or Go Home. Some people collect things for a hobby. Geeks collect hobbies. ScarletDME - The red hot Data Management Environment A Multi-Value database for the masses, not the classes. http://www.scarletdme.org - Get it _today_! Buying desktop hardware and installing a server OS doesn't make a server-class system any more than sitting in a puddle makes you a duck. [Cipher in a.s.r]

I've been using Keyspan (OK, now they're Tripplite) USA-19HS USB-to-RS232 converters for a while. Haven't had any problems with them. They run ~$25 new from Amazon. They're also supported on all the usual OS's (Windows, Linux, OS X). There's also a Gearmo USB-to-RS232 (920K) that explicitly calls out having an FTDI chip. I haven't used that one. TTFN - Guy On Aug 18, 2012, at 10:04 AM, Fred Cisin wrote:

On 08/18/2012 01:04 PM, Fred Cisin wrote: Mine is my universal if something USB doesn't work, it does with that machine.. An EeePC 701 still running Xandros. EeePC running windows is the exact opposite [its junk os]. 3) When I checked a few days ago, there were NO USB Couriers on eBay. (I've heard that they exist, but I've not seen one) Never seen one. 4) If I use a USB to RS232 adapter, HOW can I tell which ones are good? eBay listings usually do NOTR mention which internal chipset. How do I find an FTDI chipset, V the one that spews garbage characters? How about buying the genuine FTDI cable? that's what I use for RS232 and USB to 3.3V. All the others I tried sucked. Watch that some cables generate positive voltages only and real RS232 has to swing at least 3V negative or the level transition is not [or barely] seen and you get garbage chars. For devices that need a good cable run I use the 3.3V FTDI serial cable and a MAX232 to get real RS232 with CTS and DTR. The BEST USB modem I've used is the Apple. Expensive but it works. Never use Ebay. I Kept my microterm 33K and USR sportster and a PC with a real serial port. Though both work fine with the CP.M crates, VAX, and PDP11. Allison

jimpdavis wrote: I did a little footwork on these things. The trendnet is not highly recommended. I have been happy, but I would follow the others recommendations I don't know if these guys have a dog in this fight, but... *The details: * 1. Preferred processor chip: FTDI or Silabs. This is the utmost most important step. The reason why we highly recommend a USB to serial adapter with a processor chip from either FTDI or Silabs is because these are simply the best. We have extensive experience with these which shows us that these processor chips works with the majority of devices and equipment on the market. The drivers are very stable, easy to install and compatible with all versions of Windows 32/4-bit, Mac, Linux. 2. Preferred serial driver chip: ZyWyn, Maxin or NI. The serial driver chip is what is actually communicating and providing the power signals for your device connected to the USB to serial adapter. We recommend a brand name driver chip from ZyWyn, Maxin or NI because these are very reliable and works well with the FTDI and Silabs processor chips. 3. At least 5VDC output power at serial connector. We recommend a USB to serial adapter with at least 5VDC power output for the TX/RX signals. This will ensure a strong communication signal and that your device gets sufficient power. The output power is measured from signal ground to the Tx signal and the Rx signal. 4. Build-in static protection to at least 600W. Built-in static protection protects the USB to serial adapter against high voltage spikes created either by static electricity or by surges in the supply voltage. This problem can exist both at the USB end and the serial RS232 end. 5. LED lights for TX and RX activity. Not required but very nice to have. Being able to actually see when data is transmitted through the adapter is a big advantage when troubleshooting. This way its easier to find out where the problem lies; if its your computer, your device connected to the adapter or the adapter itself. *Things to avoid:* * Avoid adapters with a low-cost processor chip such as Prolific. The drivers are poorly written, incompatible with newer operating systems and creates unreliable communication. * Avoid adapters with a low output power (less than 5VDC). Low output power makes the communication unreliable or even impossible. *Further reading:* Here is an overview of all our USB to Serial RS232 adapters <http://www.usconverters.com/index.php?main_page=index&cPath=67>. Further reading: Why most USB to Serial adapters does not work with Windows 7 <http://www.usconverters.com/index.php?main_page=page&id=56&chapter=0> Small form factor adapter: Mini USB to serial adapter <http://www.usconverters.com/index.php?main_page=product_info&cPath=67&products_id=244> Cheers, -jim.

On 18 Aug 2012 at 18:43, David Riley wrote: Now that depends. For example, item 120966152129 is a Sabrent FTDI adapter offered directly from Egghead for $12.99+$1.99 shipping. Not a bad deal, since Egghead's sale price through their web store is $19. (It gets 5-star ratings). Not everything on eBay is from Chinese sellers offering junk. --Chuck

Nor is the race always to the swift, nor the battle to the strong. /~\ 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

I think that's inaccurate at least by implication. I think it's not the individual end users that want that. I think it's the intermediate companies. They want inexpensive and they want it to die ASAP after the warranty period. We don't know what end users want. They are mostly not given an chance to express a desire for anything else by purchasing decisions, since it's difficult to find anything else amid the ocean of race-to-the-bottom cheap crap. Most end users have never encountered decent reliability. /~\ 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 08/18/2012 06:43 PM, David Riley wrote: Yeah, y'know, I'm doing a bit of that myself lately. I feel awfully silly putting an FT232 on a board connecting it to a pair of UART pins on a microcontroller that already HAS a damn USB controller, but the FTDI drivers are available for lots of platforms, and they work well, and the USB VID/PID situation sucks. Do you have any thoughts here? Just how "unclean" is it to waste the on-chip USB controller just because of the suitly crap surrounding the Vendor IDs and stuff? -Dave -- Dave McGuire, AK4HZ New Kensington, PA

On 08/18/2012 11:29 PM, Mouse wrote: Well...just two comments about that: You're not a potential user of this device (no offense intended...see below), and I consider USB to be pretty standard. I must. It is a requirement from the customer, and this is for my employer. I personally prefer standard RS232 serial I/O as well, at 9600 8/N/1 like the rest of the world. The customer, however, has several thousand field personnel whose laptops do not have RS232 ports, and whose other field tasks involve connecting to USB-interfaced devices. (and many of those are FTDI-based) "Unclean" will not "go hang" here. I am incredibly anal with my designs. Period. With that out of the way...I design industrial control and communications systems based on requirements from the customer. They use OS X, Linux, and occasionally even Windows laptops in the field to access their devices. They don't mind installing the FTDI drivers on their machines to access their devices. FWIW, FTDI-based async serial ports work under NetBSD as well. I *think* there is a USB async serial I/O profile, but nobody (that I know of) has implemented it, and there has to be a reason for that. I've designed several USB peripherals and I am only peripherally (ahem) aware of the possible existence of the USB async serial I/O profile...that tells you how much traffic THAT gets. This is not a consumer device. I am not looking for an "excuse" to design in USB support. USB is not evil. In fact, for what it was designed to do, it works amazingly well. It's not even "new" anymore, so we can't use that excuse. In this case, though, this is what the (highly technical and just as anal as I am) customer has requested, and that's what they're getting. My question was an attempt to get a fellow designer's opinion of the level of design ugliness brought forth by implementing it with a separate chip, a widely used industry-standard controller (FTDI), while my microcontroller already has USB support (multiple in fact) on-chip. Fortunately said microcontroller has the ability to actually power down any peripheral controllers that are not in use. I like that a lot. One other important point here...there is insufficient space available for a DB25 or DE9 connector on the last two boards I designed. In most cases these control systems must mount inside existing systems' chassis, so physical form factor (as well as power, etc) are dictated for me. (as annoying as that is!) -Dave -- Dave McGuire, AK4HZ New Kensington, PA

On 08/19/2012 02:04 AM, Mouse wrote: Agreed mostly...The USB standard isn't "creatively interpreted" anywhere near as badly as RS232. It's not even in the same league in that department. That's the only thing I don't like about RS232. But then, 2/3/7 will get you talking to 98% of everything out there, and for the stuff that needs more, one of those little DB25->LEDs->DB25 boxes makes short work of nearly everything else. I do very much like RS232 in general; I'm quite pleased that it didn't "die off" as everyone (mostly suits with a vested interest in USB) predicted it would. It only left the desktop market. Yes, I'm sorry, I probably should've been more clear about that. Understood. Yes, that part IS evil. Suits got involved. :-( Well, the FTDI chips (assuming you're talking about the remote end) have that integrated, all nicely bundled up with very well-documented I/O and behaviors. They really are a pleasure to use. FWIW, my current design (the FTDI was used in the previous two) has a three-pin 0.1" header with TTL-level async serial for the CLI I wrote into the firmware. ;) -Dave -- Dave McGuire, AK4HZ New Kensington, PA

On 08/19/2012 02:14 PM, Tony Duell wrote: That does happen, yes. I myself never experience it because I don't buy USB devices that aren't "standardized", i.e. show up as a mass storage device or a HID (keyboard, mouse, etc) device, unless I already know it will work on whatever platform I have in mind. (what a concept...being an informed buyer...out of style, I know) Well...whoever told you that is a moron, plain and simple. Oh that could even be repurposed for even more fun things! -Dave -- Dave McGuire, AK4HZ New Kensington, PA

Lots of chat about the FTDI chips here, but I've also used the Atmel AT90USB162 chips. 32-pin TQFP, runs from 5V (provides a regulated 3.3V 50ma output) includes the usual small MCU stuff like USART, timers, comparator and SPI. Cheap--about $2 and change Q1. Anyone else like this little chip or am I just strange? --Chuck

On 20 Aug 2012 at 8:41, Jochen Kunz wrote: Looks like a nice rainy-day project. I've got a bunch of Mega8's sitting around waiting for a project. Also note the V-USB projects. Even has USB in an 8-pin ATTiny AVR. http://www.obdev.at/products/vusb/index.html The AT90USB162 is USB 2.0. --Chuck

On 20 Aug 2012 at 9:51, Eric Smith wrote: Of course, and I believe that the V-USB site makes this very clear. I've got a carton of early USB HID peripherals with non-detachable cables. They all use the Intel N82930A3 controller (68 pin PLCC) No modern (i.e. 2000-present) system even sees the things--that's an indication of how far USB has come. --Chuck

On 20 Aug 2012 at 12:04, Glen Slick wrote: Indeed they are, complete with LCD display and volume control knob. Firmware's in an OTP 27C256 soldered-in EPROM. Intended for use on the Infinia 7200. Somewhere I have the documentation for the Intel devkit that used the 82930, but I doubt that the devkit would be recognized either. I got then NOS cheap mostly for the LCD displays. Academic now, since there are better choices, so they're just moldering away. I do have an Infinia 7230, but the HID peripheral for those is different and the one for the 7200 isn't recognized or detected. --Chuck

On 08/20/2012 10:22 AM, Chuck Guzis wrote: To me, that's an indication that the things had badly written firmware or something. There's no reason that low-speed USB 1.0 HID devices shouldn't work on a current USB 2.0 or 3.0 system. It would be interesting to put such a device on a modern system with a USB analyzer (hardware, not software) and see what's going wrong.

He ws jsut repoprting what he was told when it was given to him. He is most certianly not a moron, he's a darn good embedded systems programmer. He had no use for it (which actually suprised me), but he knew I'd use it... FWIW. Black Box still sell the thing (DT200A) at a very high prise... Things I didn't mention about it. It's got a Dallas RTC chip in it. When I got it. There are 2 RS232 connectors, male and female, wired pin-pin (alas it can't intercept and modify the data). Pins 2 and 3 are monitored by tehe 2 channels of the Z8530, there's a relay [1] that conencts a driver to pin 2, so the thing can run as a terminal. There's another DB25 socket on the other side of hte case. It's wired -- mostly -- as a PC parallel port, you can sue thing unti to test parallel printers or use such a printer to log the incoming data. Note I said 'mostly'. One pin is an RS3-level output from one of th Z180's serial ports, another pin is used as a serial input. This lets you control the thing remotley. There was supposed to be an adapter included with it for this (it's not just wires, there's a resistor -- I guess 4k7 -- in series with the incloming data line). I didn't get it, but I soon figured it out. [1] There are 4 relays on the PCB. They are bistable latching relays controleld by a '374 chip, each relay coil is tied between 2 of the Q pins of said chip, so you can energise it either way round to flip the relay one way or the other. The 4 rleays control ; Main power on/off ; TxD output to Rs232 pin ; TxClock output to RS232 pin (used in syncrhonous modes) ; RTS on. There is one bit of poor design IMHO. The firmware allows you to select a lot of bauyd rates, includign some obscure ones that I would never need, but it on;y goes down to 75 baud. And the thing can handle 5 bit Baudot data (well, probably not true Baudot, but you know what I mean). Having 50 baud or 45.45 baud would be useful for that. It certianly could. The only thing I don't have data on is the existing firmware. ALl the ICs are standard, the LCD is a standard module, etc. But it's quite useful to me in its present form. -tony

On Aug 19, 2012, at 3:23 AM, Dave McGuire wrote: We did that on the last project before we moved to FTDI chips. The customer's "engineers" kept plugging power into it, despite the fact that the power connector had four pins and was keyed. Some folks you just can't reach... BTW, the FTDI approach is not without its flaws. The specific thing that sticks in my craw is that unlike RS232 cables, if you unplug the port with the terminal app still open, the terminal program goes batshit because its device has just disappeared out from under it, with varying results from just having to restart the terminal program (GNU screen) to a bluescreen (occasionally HyperTerminal on WinXP, though honestly that was probably a driver issue). - Dave

On Aug 19, 2012, at 2:04 AM, Mouse wrote: Well, not the only one. That's my primary issue with USB, as it is with PCI. But I do recognize that once speeds get into the tens of MHz, things rapidly fall out of the "hobbyist" range, so much like most Ethernet implementations, I'll accept a third-party VLSI controller chip to perform translation to something else (e.g. CMOS- level serial) to use it. - Dave

On Sun, 19 Aug 2012 01:16:38 -0400 Dave McGuire <mcguire at neurotica.com> wrote: You talk about USB CDC, Communications Device Class. This device class features several interfaces that e.g. mimic Ethernet or async serial connections. I am really surprised why it doesn't get widespread use like USB mass storage. Either it has some major design flaw. Or it is "too open". I.e. vendors like FTDI or Profilic are not able to "lock in" customers by folowing a generalized device class. Maybe it is just lazzyness of developers. They prefere to use a ready made chip that implements all the USB stuff then to implement a CDC device in there own firmware. Have a look at this application notes: http://www.atmel.com/images/doc4322.pdf http://www.atmel.com/images/doc7619.pdf and the official class definitions: http://www.usb.org/developers/devclass_docs/CDC1.2_WMC1.1_012011.zip -- \end{Jochen} \ref{http://www.unixag-kl.fh-kl.de/~jkunz/}

Can't you clone the VID/PID pair and make it answer just like a FT232 chip does? --- Enviado do meu Motorola PT550 Meu site: http://www.tabalabs.com.br ----- Original Message ----- From: "Dave McGuire" <mcguire at neurotica.com> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Sent: Saturday, August 18, 2012 9:18 PM Subject: designing in USB-serial ports, was Re: Hans Camenzind, Inventor of the 555, dies.

[top-posting and no-trimming damage repaired manually -Mouse] Probably, but that would likely get someone upset at you if the result were to achieve wide distribution. Sometimes hardware costs - either primary (eg the chip) or secondary (eg board space, power draw) outweigh software costs. Would it be too much to ask that you not drop ads for your devices in your email? I already get far too many ads as it is, and don't need more - especially shoehorned into otherwise interesting discussions. /~\ 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 08/18/2012 11:37 PM, Alexandre Souza - Listas wrote: That's easy. The hard part is speaking the protocol that the FTDI chips speak over USB. That information is floating around, but this is a commercial product, and aside from not being able to afford the design time of writing the code to implement that protocol, I also can't afford to get fired for causing my employer that level of legal exposure. ;) -Dave -- Dave McGuire, AK4HZ New Kensington, PA

? Yeah, y'know, I'm doing a bit of that myself lately.? I feel awfully - Hardware costs and board space - obvious - Firmware development costs and time schedule.? It MAY be quicker to drop the FT232 chip in and use the UART than to bring up the USB interface for the first time using the developer library.? If you already have one project implementing the same protocol, this is not much of an issue, though. - Driver issues.? The FT232 drivers are easily installed on most OS's and work well.?? For the on-chip solution, the Communications Device Class (CDC) virtual COM port protocol is pretty well supported by Windows 7, Linux (and other Unix-like systems such as OS X) out of the box.? Not sure about XP or older windows installations, though. - Vendor ID/Product ID: If you implement on-chip, you can encode these directly in firmware.? The FTDI chip, as far as I can tell, can only be programmed via the USB side, which means an extra step during manufacturing:? You will have to hook up the device and run a utility that sets the VIP/PID codes.? For me, that's a disadvantage for the FTDI. So looking at a new project, it would depend on the scenario: - low volume, high margin, quick development time: FTDI is great. - high volume: pretty much would want the on-chip solution. - update of an old design, including move to USB from RS-232.? Perhaps better to go with the FTDI, and avoid the need to port to a newer uC, unless volumes are expected to be high, or other requirements make the move to a new chip necessary. - pre-existing code for the on-chip USB engine is already written for your chip--then FTDI seems redundant - host platform somehow has broken CDC driver, or FTDI driver, choice is made for you! BTW, if you're making a lot of USB devices, it's not that expensive ($1000 USD) to get a VID (as long as you don't care about the logo, or consortium membership). Dave

What I would prefer (at least for devices that don't need the high data throughput of USB) is that the device has an asynchronous port brought out to some suitable connecotr and that said devie is shipped with a USB interface cable that plugs into said connecotr. And of course that all this is documented. That way, users that prefer USB and/or have modern PCbs can just plug in and go. I can make a level shifter, plug that in, and conenct said device to an RX232 port. Bust of all worlds... -tony

On Sun, 19 Aug 2012, David Riley wrote: ...or they manage to break/pull the USB pigtail cable out of the USB to serial adapter. I repaired one such adapter where the user had attempted to /superglue/ the individual wires to the pc board inside the adapter (also breaking many of the clamshell case's clips in the process). It took me longer to scrape and remove all the superglue from the pc board than it did to solder and then reinforce the connection so that it wouldn't break again. I wish now that I had taken a photograph of that one.

Fred Cisin <cisin at xenosoft.com> wrote: telnet at least? # telnet www.adafruit.com 80 > test.html "GET /blog/2012/08/16/hans-camenzind-inventor-of-the-555-dies/ HTTP/1.1 Host: www.adafruit.com Connection closed by foreign host. Exit 1 # awk '/<blockquote/ {block=1} /<\/blockquote>/ {block=0} { if(block==1) {gsub(/<[^>]*>/,"",$0);print;} }' test.html Hans Camenzind, the Swiss emigre analog guru who invented one of the most successful circuits in electronics history and introduced the concept of phase-locked loop to IC design, passed away in his sleep at the age of 78. The news was reported today (Aug. 15) by Sergio Franco, an emeritus professor of electrical engineering at San Francisco State University in an email. Camenzind came to the United States in 1960 and worked for several years at some of the storied names of the newly developing semiconductor industry: Transitron, Tyco Semiconductor, and Signetics. In 1971 he joined the ranks of entrepreneurs by founding InterDesign, a company specializing in semi-custom integrated circuit design. It was there, working under a contract with Signetics, that he invented the 555 timer.?? Signetics commercialized the device in 1972, and it went on to become one of the most successful in the industry&#8217;s history. The device, used in oscillator, pulse-generation and other applications, is still widely used today. Versions of the device have been or are still made by dozens of major semiconductor vendors, including Texas Instruments, Intersil, Maxim, Avago, Exar, Fairchild, NXP and STMicroelectronics. #

Hi Atually SE555, not NE555 that was a licenced copy. Dwight

Hi Chuck I would guess you are correct here. I just recall using a numberof Signetics 555's and they were SE555's I'd always thoughtthe NE555 number was National Semi's number.I do recal the S5400/N7400 numbering, now that you mentionit.The 555's were much better than the 74121/122 chips forlonger pulses. It may not have been an error. Some of these part werefussy about temperature. Maybe the meant C.Anyway the air conditioning bill would put most people offwhen using these ;)Dwight > From: cclist at sydex.com