Halt and Catch Fire (AMC Series based on the founding of Compaq) - Page 1
Forum section: electronics / general

author: Stonent
author_rank: Super Contributor
timestamp: May 08, 2014, 05:29:41 am
content: Has anyone heard of this? I just saw the trailer today. It's a new series on AMC about the ex-TI Engineers and the founding of Compaq and their quest to find a way to legally reverse engineer and clone the IBM PC.One thing I read about it specifically said "Ask anyone where the computing industry as we know it was born and the'll likely say Silicon Valley, but they'd be wrong, it was Texas"To those who aren't familiar with how Compaq started, they figured since the IBM PC was built with standard commonly available parts, that it shouldn't be too hard to clone and sell, but the key was the BIOS ROM which was proprietary and copyrighted software. So they had to figure out how to clone its function without cloning its software.It's probably one of the greatest electrical engineering stories of the 20th century and the ensuring legal case opened up the doors to the entire PC industry as we know it today.

author: jh15
author_rank: Frequent Contributor
timestamp: May 08, 2014, 05:43:48 am
content: I haven't seen it but I hope it gets the concept across that copyright breaks innovation.Why doesn't the broken patent system really screw up and make patents last until 75 years after the patent's originator, person or factory.

author: Stonent
author_rank: Super Contributor
timestamp: May 08, 2014, 06:10:34 am
content: I found this video on youtube where the real founders in the 1980s are talking about the company being founded.

author: Richard Crowley
author_rank: Super Contributor
timestamp: May 08, 2014, 06:40:12 am
content: The DMCA would likely make the action of reproducing the BIOS functionality illegal today.Phoenix had to use a "Chinese Wall" or "Clean Room" method to reverse-engineer IBM's original PC BIOS.And then they had to take out a multi-million dollar insurance policy to reassure their customers.QuoteWell, you could make a strong case for Boca Raton, Florida where the IBM group lead by Bill Lowe and Don Estridge developed the IBM 5150 (aka. the first "PC")

author: dfmischler
author_rank: Frequent Contributor
timestamp: May 08, 2014, 10:15:34 am
content: Quote from: Richard Crowley on May 08, 2014, 06:40:12 amI would disagree. That was just another proprietary machine. Quite a few other companies were building something like it at the time; some of them with the same chips. The key was that it got popular, and somebody figured out a more-or-less legal way to clone it. The existence of an "open standard" is what propelled the industry to where it is now, for good or ill.

author: London Lad
author_rank: Regular Contributor
timestamp: May 08, 2014, 10:25:23 am
content: Not 100% accurate but a good time line of how this (British) invention developedhttp://www.computerhope.com/issues/ch000984.htm

author: Stonent
author_rank: Super Contributor
timestamp: May 10, 2014, 12:46:05 am
content: I just noticed, the actor that plays the main character in this show played King Thranduil in The Hobbit.http://www.imdb.com/name/nm1195855/?ref_=tt_cl_t1

author: Legion
author_rank: Frequent Contributor
timestamp: May 22, 2014, 11:34:07 pm
content: You can watch the first episode on AMCs website here:http://www.amctv.com/full-episodes/halt-and-catch-fire/3571290828001/i-o-full-episodeIt was fantastic. Highly recommended.

author: SirNick
author_rank: Frequent Contributor
timestamp: May 23, 2014, 12:40:48 am
content: Hope it's better than The Walking Dead and Breaking Bad. At this point, I've associated AMC with over-hyped and tedious original programming. Also: Their first album was better, you kids get off my lawn, so on so forth.I definitely see the value behind patents, copyright, and trademarks, however.... As long as someone stands to profit, these concepts will be drawn into the realm of absurdity. Disney keeps indefinitely extending the trademark term, people actually have to pay royalties for singing Happy Birthday, and you can't invent anything these days without stepping on a patent landmine. I don't think that kind of abuse was the intent of any of those protections.Thereshouldbe a reward mechanism to allow innovators to recoup their costs, but what we have now is not the right solution. At least not anymore.

author: Rasz
author_rank: Super Contributor
timestamp: May 23, 2014, 01:06:51 am
content: Quote from: Richard Crowley on May 08, 2014, 06:40:12 amNo it wouldnt. DMCA is about DRM, not APIs.Util a month ago US had a very good case law established by Oracle vs Google stating that APIs are NOT copyrightable. Judge learned Java just to know whats up during the case!http://www.theguardian.com/technology/2012/jun/01/oracle-google-api-decision-freeSadly we cant have nice things when big corporations are free to bribe everyone, so clueless appeals court reversed ithttp://arstechnica.com/tech-policy/2014/05/oracles-java-api-code-protected-by-copyright-appeals-court-rules/

author: Richard Crowley
author_rank: Super Contributor
timestamp: May 24, 2014, 06:19:18 pm
content: Quote from: Rasz on May 23, 2014, 01:06:51 amI was referring to the mere ACTION of attempting to REVERSE-ENGINEER the functionality in order to reproduce it. Even the ACTION is made illegal by DMCA. Or at least that is how I understand various explanations of the incomprehensible legal mumbo-jumbo.

author: Rasz
author_rank: Super Contributor
timestamp: May 25, 2014, 03:15:54 am
content: Quote from: Richard Crowley on May 24, 2014, 06:19:18 pmNo it is NOT. DMCA makes illegal act of reverse engineering DRM for the purpose of breaking it.

author: echen1024
author_rank: Super Contributor
timestamp: May 25, 2014, 06:53:44 am
content: This show is actually really quite good.

author: TheRevva
author_rank: Regular Contributor
timestamp: August 18, 2014, 09:54:50 am
content: I wonder how many people out there who, in the 'spirit' of true hacking, have already downloaded and watched all 10 episodes released to date before being aired in their local country?I'm willing to bet a small pile of Mike-Rowe-Soft CDs (aka 'holographic beer coasters') that it's a fairly significant number!

author: VK3DRB
author_rank: Super Contributor
timestamp: August 18, 2014, 11:39:52 am
content: Actually IBM stuffed up with the PC.It was originally to be marketed to hackers to fill a small niche market of those who were into microcomputers, like many of us here. But quickly they realised the product had wider merit because it became the defacto standard for hackers and spread into the general corporate world. They had no vision of how it would change the much of the world.They used the Intel 8088 micro - a segmented addressing nightmare and crappy architecture in comparison to the superior Motorola 68000.The biggest screw up is that IBM published the complete BIOS listings and the circuit diagrams, so that other companies could make option cards like graphics cards etc. IBM made a gross miscalculation. Instead the more lucrative market was in cloning the IBMPC. Even though most of them were crap quality, the prices of IBM Clones were a fraction of the IBM machines.IBM got greedy for money with big fees on Microchannel architecture and the overpriced OS/2 Warp operating system.If they had one ounce of innovative marketing skills, they would have given every university student on the planet a fee copy of OS/2 Warp, and Microsoft would have amounted to not much. But they paid for their ineptitude because now OS/2 is dead and buried. The funny thing is IBM thought the world would accept OS/2 if all the employees were forced to use it. In fact IBM employees were forced to use OS/2 ("Orrible System 2") because they thought the religion would spread. In the days of the dodgy Louis Gerstner, IBM employees were forced to use OS/2, when the real world was embracing Windows. Incidentally Microsoft wrote OS/2, not IBM. And only 16 bit applications could run on OS/2's pathetic Windows shell, not 32 bits.

author: macboy
author_rank: Super Contributor
timestamp: August 18, 2014, 04:48:34 pm
content: Quote from: Rasz on May 25, 2014, 03:15:54 amMore generally it makes it illegal to circumvent copy protection, or to show someone else how to do it (e.g. distribution of decryption keys or proprietary algorithms).The PC BIOS was undoubtedly copyrighted, but was not copy protected; no encryption or obfuscation was used. It was just raw machine code in a ROM chip.

author: Richard Crowley
author_rank: Super Contributor
timestamp: August 18, 2014, 05:25:03 pm
content: Quote from: macboy on August 18, 2014, 04:48:34 pmWhich is why practically any modern piece of hardware/firmware/software you use required that you agree to not reverse-engineer it.Of course that doesn't prevent anyone from reverse-engineering (or disassembling, or whatever). It just provides their attorneys something to hit you with.\The BIOS for the original IBM PC clones were written from scratch in a "clean room" based only on the interface specs.But I can't remember. Is there STILL a court case (or three) about whether published API specs are "protected" from reverse-engineering?

author: nctnico
author_rank: Super Contributor
timestamp: August 18, 2014, 05:53:13 pm
content: Quote from: wilfred on August 18, 2014, 10:14:33 amJust download from your favorite download site.

author: SirNick
author_rank: Frequent Contributor
timestamp: August 19, 2014, 01:53:54 am
content: Quote from: wilfred on August 18, 2014, 10:14:33 amAll very subjective, and of course, I speak for myself alone: <rant>That's part of what baffles me about Breaking Bad's popularity. None of the characters are likable, so at most you relate to their actions for a short time, then they're back wallowing in their own self-made misery. I didn't find the writing to be all that stellar. Same squabbles, a bunch of tired cliches... ("But thecharacter arc!" Yeah, yeah...)I only made it through the first two seasons because everyone was always saying how great it was, so I kept waiting for it to get better. It didn't. For some reason, I stuck it out to the very end since I had already invested myself that much. I felt relieved it was over. It wasn't quite the masochistic humanity-sinking experience that Nip/Tuck was, but it was close.Similarly, The Walking Dead was mildly interesting through the second season for the moral questions it raised. I continued to watch most of the 3rd season despite feeling the plot was getting repetitive; partway through the 4th, I finally gave up. Just WAY too tedious, and everyone's always miserable. What's entertaining about that?I see a little of that "AMC-ism" in HACF too -- the dingy camera filters, the constant bickering, the lack of a truly likable character (Donna's usually alright, and props for the genuinely smart female role) -- I guess they think dreariness makes it "gritty." But the subject matter is interesting enough that I'm giving it a shot. We'll see.</rant>Interestingly, I had this conversation with another group of forum-goers elsewhere and mentioned Dexter and Homeland as examples of similar, but IMHO, far superior dramas. It seems our taste was 180-deg out of phase on that one. I also thought The Newsroom was (is) excellent. May be just a different cup of tea.

author: Richard Crowley
author_rank: Super Contributor
timestamp: August 19, 2014, 02:09:48 am
content: Yeah, what Sir Nick said. Never could figure out why people liked that show.

author: westfw
author_rank: Super Contributor
timestamp: August 19, 2014, 03:33:15 am
content: QuoteI watched part of the first episode and got pretty disgusted.There wasn't much to "reverse-engineer" in the IBM PC. It was a very vanilla design with no custom parts. The full specs AND SOURCE CODE for the BIOS were published (I think I still have that notebook around somewhere.) The problem was the copyright; if you wanted to duplicate the BIOS for your own clone, you had to find someone who could WRITE the BIOS from the specs, who had never looked at the IBM Source (thus "clean room") This was a different and easier problem. A boring problem, actually.And then it seemed to have 2000-era business ethics and considerations that I don't remember existing in the early 1980s (not that I was involved in a PC compatibles business, but ... all the customer and trade press buzz was about features and costs and "maybe personal computers will hit mainstream" rather than the legal and "big profits!" issues.)Bah humbug!

author: coppice
author_rank: Super Contributor
timestamp: August 19, 2014, 07:22:08 am
content: Quote from: VK3DRB on August 18, 2014, 11:39:52 amEr, no. The PC for a niche market was the one before the IBM PC we all recognise today. It had a proprietary IBM CPU and you could only use an interpreter on it (some kind of BASIC, I think). The IBM PC we all know was a result of IBM worrying about the number of small businesses who found they could do their basic accounts and database activities on the Z80 based CP/M machines which were becoming popular. IBM made a sort of "next generation" CP/M machine, with a 16 bit core. They wanted a 16 bit CP/M on it, but when Digital Research didn't play ball, they got a CP/M clone from Microsoft - MSDOS.Quote from: VK3DRB on August 18, 2014, 11:39:52 amThe screwup here was Motorola's. The 68008 was so late it was irrelevant when it appeared. There was no way a full 16 bit bus or the huge expensive 64 pin ceramic package of the 68000 was going into this simple machine. If the 68008 had been properly planned into the release of the 68000, in a low cost 40 pin package, the IBM PC would probably have used it.Quote from: VK3DRB on August 18, 2014, 11:39:52 amThat was actually a very smart move by IBM. They didn't want to stop competitors. Anti-trust concerns meant they only wanted to slow their competitors down. They did enough to ensure that, while making the machine open enough that third party cards flourished, and the PC ended up in all sorts of unexpected applications, broadening its market.Quote from: VK3DRB on August 18, 2014, 11:39:52 amMicrochannel was a very stupid idea, but OS/2 Warp wasn't around in those days. The original OS/2 was a screwup, mostly because it was locked to IBM's microchannel hardware. That is what seriously limited its appeal. I don't remember it being very expensive. The whole machine was more expensive, as a full scale OS like OS/2 needed a lot more memory than was being fitted to most machines at that time.Quote from: VK3DRB on August 18, 2014, 11:39:52 amOS/2 was IBM's design and product. Microsoft were just body shop contractors helping the pool of IBM developers. At that time there were only 16 bit Windows apps, so I am not sure what your last sentence is supposed to mean.OS/2 had a lot of good qualities, but its key problem was it was seen as an attempt by IBM to lock people in. Most of us thought "the only reason they aren't putting Unix on that thing is because they want to screw around with us" and we mostly ignored it. Strangely, when Microsoft launched NT some time later, and there really were 32 bit Windows apps, many people had a very different attitude. They saw it as the dawn of low cost versions of things which had always run on Unix, like super expensive CAD tools. They had no justification for why that massive price reduction should occur, when it changed nothing in the cost structure of the applications supplier.

author: westfw
author_rank: Super Contributor
timestamp: August 19, 2014, 08:13:07 am
content: Quote8088/8086 wasn't so bad. Position independent code for free. For that 1M max address space. The 286 was a nightmare attempt add more address space. (but Intel apparently adapted faster than Motorola, and ended up winning in the end.)QuoteWell, yeah. Except perhaps hardware-wise.QuoteApple and Commodore (Amiga) didn't seem to have many problems. There's no particular reason that IBM couldn't have used the 8bit expansion bus with 16bit main memory. The original MBs ended up with 32x memory chips anyway (4*64k*in the most popular configuration. (of course, those 68k systems were a couple years (and a couple Moore Generations) later than the original PC design.) SUN was doing 68k systems in the early 80s, but they were much more expensive.QuoteThe 68008 was a 48pin package when it finally came out anyway.If HCF had been about the whole mainframe/workstation/pc religious battle, it would have been more interesting. To have made it all about "cloning the PC" was silly. In that timeframe, vendors were still proudly building MSDOS non-IBMPC systems (I owned an HP150, for instance.)

author: george graves
author_rank: Super Contributor
timestamp: August 19, 2014, 08:31:24 am
content: I'm in the US, and even I had issues with the AMC website. Turned it was adblock plus. Turn if off for that page (and the eevblog of course!) and all is good.So far it seems like Mad Men with a touch of the Social Network. But without the amazing dialog of Aaron Sorkin. Also if you're into great dialog, and not an American hater - check out "The Newsroom"....

author: coppice
author_rank: Super Contributor
timestamp: August 19, 2014, 09:26:21 am
content: Quote from: westfw on August 19, 2014, 08:13:07 amAs you said, the Suns were expensive machines, but so was the original Apple Lisa. The Apple Mac was launched 2.5 years after the IBM PC, and was still not a low cost machine. They crippled it with too little RAM and disk space to try to keep its price bearable (yes, it had a lot more RAM than original IBM PC, but the Mac launch after a massive fall in memory prices). The Amiga came 1.5 years after the Mac, and another massive fall in costs. By that time the IBM PC AT was out, with 16 bit RAM and I/O, and the cost structure of the original IBM PC was no longer relevant.

author: VK3DRB
author_rank: Super Contributor
timestamp: August 19, 2014, 01:37:54 pm
content: Quote from: coppice on August 19, 2014, 07:22:08 amWrong. The PC before it was the 5100, 5110 and 5120 machines. They were designed for professionals and small business, not for hackers. I used to repair these machines and none of my customers were general consumers or hackers. The cost was prohibitive for a start.QuoteCorrect. Except most models had TWO interpreters on them - BASIC and APL.QuoteI was present at the very first internal announcement of the IBMPC at IBM Australia - at 211 Sturt St, South Melbourne in 1981. The senior marketing manager clearly stated to us engineers the machine was aimed at a very small market that could grow potentially make up 2% of IBM's business - the hackers market (the term that was used at the presentation). Hackers in those days being people who were interested in modifying what was under the bonnet, unlike the bastardised original term "hacker" used by the media today. Very quickly, the official launch aimed it at small businesses and home owners who knew nothing about computers (via the Charlie Chaplin advertisements). IBM sold the machines through VARs, VADs and VAMs, which limited their aceessibility to the home user.Not many business ran CP/M machines back in 1981. IBM never saw the CP/M machines as a threat in 1981. In fact, few businesses owned a computer at all in 1981.QuoteThe IBM antitrust case was dropped in 1982. IBM specifically intended publications of the technical details was for OEMs to make I/O boards and peripheral, not the main system. This OEM "partnership" paradigm was spelled out on numerous occasions in the early 1980's within IBM at technical and marketing meetings and in publications. It backfired over time. IBM fought tooth and nail to keep market share by offering exceptional quality in manufacture (and they did this very well), but by the the mid 1990's, IBM realised that people want low cost above quality. Today, you cannot buy an IBM PC or even a laptop. They lost the market completely.QuoteWrong. Microchannel was technically quite superior to ISA... better specs, smaller form factor, 16 AND 32 bit buses and unlike with ISA the I/O board could become the bus master.And the original OS/2 wasNOTlocked to microchannel. I was the first person in Australia to install OS/2 in 1987. I got a copy of OS/2 1.0 prior to release the very morning the first proof copies were received at IBM's Diskette Replication, for engineering purposes. It was installed on an IBM 80286 machine with 2MB RAM. The bus was ISA. It ran without a hitch and I found it much more useful than DOS, especially with applications running on a Token Ring network.Warp was more expensive than Windows in the earlier days. Arguably the ease of piracy of Windows made it popular, as did its relatively lower price and better marketing. By the time IBM dropped its price on OS/2 Warp, it was too late. They lost the battle badly and surrendered in the late 1990's with their tail between their legs.There are a time when OS/2 Warp was released that Warp may have defeated Windows, but IBM screwed up with lack of innovation in marketing above everything else.

author: nctnico
author_rank: Super Contributor
timestamp: August 19, 2014, 04:32:42 pm
content: Quote from: george graves on August 19, 2014, 08:31:24 am'The Newsroom' is nice too. A lot of good criticism on American society!When I hear or read about a new TV series I just check the first two episoded to see if it is something worth watching. The first episode of 'True detective' is just crap (skip it) but in the second episode the story starts to catch on.

author: Bassman59
author_rank: Super Contributor
timestamp: August 19, 2014, 05:07:25 pm
content: Quote from: SirNick on August 19, 2014, 01:53:54 amMy wife and I started re-watching "The Sopranos" from the beginning, and it's impressive how well that show holds up. I mean, it's about a bunch of psychopaths who live by a code which they regularly bend and break, but it's fascinating. The writing is snappy and the acting goes right up to the line of being a ham sandwich but doesn't cross it (too often, at any rate).Plus, I'm from northern New Jersey, so I recognize all of the landmarks.As for "Halt And Catch Fire," there are technical errors in the show that make me want to throw things at the television. And beyond the glaring errors, there were things which were obviously there to make the reverse-engineering process seem more visible to the (not-techy) audience. (Hello, HP1630 logic analyzer, anyone?) Plus I hate the sales guy character, and I don't remember any female hackers like Cameron. (Girls like her were always at the punk rock shows I went to the night before Circuits exams, though.)

author: SirNick
author_rank: Frequent Contributor
timestamp: August 19, 2014, 07:06:54 pm
content: It's dramatized, so I forgive the technical errors. On a whole, it does a pretty good job of being technicalenoughwithout losing the general populace. I roll my eyes from time to time (like the idea that a power surge from plugging in a vacuum cleaner is going to destroy floppies), and then raise my eyebrows when they go into territory I didn't expect them to touch (like talking about PSK modulation). The writing would never hold up to the scrutiny of a bunch of engineers, but that's OK. It's fiction. Just be close enough that I can suspend disbelief and I'm good. (Read Dan Brown's Digital Fortress for an exercise in WTFery.)Similarly, I disagree that the truth about cloning PCs and battling it out for market share would be a more interesting series. A more interesting documentary, perhaps, but fiction? Nah, cutting-edge, seat-of-the-pants, hardware hackers giving birth to something that can change the industry -- that's a fun plot. The fact that itvaguelyresembles actual history is a bonus.Cameron is a tough sell, I agree. How you are expected to jump straight out of early college courses with her level of experience ("Who knows anything about VLSI?") is beyond me. However, I did work with a coder that was fresh from high school, and showed a maturity well above many of the professional programmers I've met. I attribute that to his working on a few OSS projects, and learning practical skills from that ethos.Finally -- The Newsroom -- for anyone that hasn't seen this show, you should find the intro to episode one and watch it. It had me hooked in the first five minutes. You don't have to be pro-American nor anti-American. It's a sobering, critical view of America's faults, but it's all completely fair. It's not bashing for the sake of it. At some point you have to stand back and understand where your weaknesses are, to prevent being hoodwinked by them. The fact that this level of honesty has to come from a fictionalized TV show, and not the genuine news media, is a little sad, but welcome nonetheless.

author: westfw
author_rank: Super Contributor
timestamp: August 20, 2014, 10:17:34 am
content: QuoteI dunno. I was almost her, sort of. I mean, I followed personal computers in HS (late 70s), and poured over the Intel 8086 manuals when it came out while I was in college. My college was gifted a bunch of SDK86 development systems (kits!) from Intel, and we assembled and fiddled with them in my Senior "Digital electonics" class. Me more than most, cause I had the programming bug even though I was an EE. I did my Senior Design Project on that board; all in x86 assembler (cross assembler running on a CPM system.) That was pretty much all it took to be an x86 "expert" on graduation (81); you didn't need to know about the chip internals and VLSI, you just needed to have been paying more attention than the "pros" who were building Qbus cards or programming IBM Mainframes in PL/1. When the IBM PC came out and my first employer bought one with "incentive funds", I was all over it. Unix to x86 cross assembler from MIT: cool. Published BIOS interface: excellent! H19 terminal emulator: done. XMODEM upload/download from the mainframes that were my "real job": done. Try out Microsoft C, v1, in the days when that meant having your source code on one floppy drive, and the various passes of the compiler on the other (switch floppies for each pass!): yeah (eww!) Go off and become rich and famous selling PC communications SW: well, that part didn't work out so well, but I did try. (learned a lot about SW publishing legalities. Spent money on lawyers. Sigh.) (and I stuck with the mainframes for another couple of years instead. Work entirely on PC-class machines? Nah; no Internet, no multiuser stuff; mainframes were a lot more fun. Then got heavily into networking, largely because of ... my x86 experience.)The point is, you only needed to know a *little* more about x86 than the people who were busy doing other things to be a "x86 wiz-kid", and that wasn't all that hard. And you do get that class of people coming straight out of universities...

author: SirNick
author_rank: Frequent Contributor
timestamp: August 20, 2014, 06:49:51 pm
content: OK, I guess I could see that. My only eye-rolling moment really was the part where he meets her in that classroom. The roll-call of technical disciplines seemed over the top, but you're right -- the systems were far less complicated, so learning "a lot" about several things wasn't quite the career-long process it is becoming now. Aside from that scene, she's a talented assembly hacker (no problem there), and owned up to not being a hardware expert when she tried recruiting Donna for her start-up.Now, Claudia from Warehouse 13? I suspect her skills are being exaggerated.

author: German_EE
author_rank: Super Contributor
timestamp: August 20, 2014, 08:59:00 pm
content: Power surges and floppies.WellIf you had either an Apple ][ or an Apple //e with floppy drives you knew to ALWAYS open the floppy drive door before powering your system on or off. If you did something with the power and the heads were in contact with a disc they were nearly always corrupted. So, given that this is about the same time period it's possible that the surge from a vacuum cleaner could do something nasty.I think I'm showing my age

author: SirNick
author_rank: Frequent Contributor
timestamp: August 20, 2014, 11:18:02 pm
content: Wow. That is tremendously bad design.

author: nctnico
author_rank: Super Contributor
timestamp: August 21, 2014, 12:09:35 am
content: Not really. Floppy drives are a standalone component and they have an active low write enable (IIRC). If the power sequencing is slightly off then you could activate the write head during power up or power down. I still make sure there is no disk in a disk drive when I switch a device on or off.

author: SirNick
author_rank: Frequent Contributor
timestamp: August 21, 2014, 07:41:18 pm
content: So am I the only one who tries to think about what happens to logic levels that control some other device when the voltage goes below normal operating level?

author: SeanB
author_rank: Super Contributor
timestamp: August 21, 2014, 08:01:11 pm
content: Many designers are caught out by supply rails that either power up out of sequence, or that drop out too fast or too slow. Some IC's have very specific requirements for power supply, in that they need the supplies applied in the correct sequence, and that they ramp up within a defined time. A lot of microcontrollers with brown out detection will not reset properly if the initial supply comes up too slow and the on chip reset circuit times out various parts at different voltages and then it operate erratically or not at all.