test-drb October 1998

test-drb@ccmp.vtda.org

175 participants
1141 discussions

Fluke multimeters: infringement of international safety standard

by Philip.Belben＠PowerTech.co.uk

This came round at work. I don't know if any of you have a Fluke 80 series - IMHO the Fluke 87 is still one of the best multimeters that money can buy. (I don't have that much money so I have a Fluke 29 and am thus not affected.) However, I believe electrical safety is something to take very seriously. I have received nasty shocks and nastier burns from accidentally touching the mains (yes, even the earth conductor), and the rectified mains in switch mode power supplies is even nastier. Not to mention high voltages in monitors, etc. Philip. ---------------------- Forwarded by Philip Belben/PTech/PowerGen on 22/10/98 17:23 --------------------------- From: Chris Bright on 22/10/98 09:22 To: George WEDGWOOD/Westwood/PowerGen@PowerGen cc: (bcc: Philip Belben/PTech/PowerGen) Subject: Fluke electrical multimeters: infringement of international safety standard Recently Fluke Corporation discovered a small dimensional shortfall within its 80 Series III digital multimeters and 787 process multimeters. This means that the meters do not comply with IEC 1010-1 which deals with double or reinforced insulation in the 1000V Overvoltage Category III rating. The problem may be solved by fitting a replacement battery cover obtainable free form Fluke. The affected range of products are: Model Serial number Manufactured Date From To From To 83 III 69810781 71200001 29 Dec 1997 7 July 1998 85 III 69810501 71200001 29 Dec 1997 7 July 1998 87 III 69910001 71200001 12 Jan 1998 7 July 1998 787 All units prior to 71200001 7 July 1998 For further information please contact the local Fluke Sales Office on Tel 01 923 216400. [NB that is a UK number local to us at Nottingham. PDB] Chris Bright Power Technology File DXHA/SAFT/ELEC/OFFC

26 years, 2 months

Building a Z-80 (64bit!!!)

by franke＠sbs.de

> < I am trying to basically build a 64Bit Z-80 on a board. What I am > < looking for is: Anyone know of any chips that are EXTREMELY simple > < micro-controllers but, work at EXTREMELY high clock rates??? I wanna p > < a few on a board with some memory and made a 64-bit Z-80. I'd like th > < processor to operate at 300Mcyc (or faster) clock speeds so, I figure I > < need micro-controllers that operate at about 900 Mcyc to do the work. > Wait till April first for this. <rotfl> > I don't think you were listening when we were discussing propagation > delays. To deal with 300-900Mhz clock your talking 4-6layer etch and > some really fast logic. The .33nS memory will be tough to buy. Be > prepared to dump a few DecaKilobucks into the attempt after all you'll > need a really fast logic analyser and O'scope to see what you missed. Gee Allison you are talking like an engeneer - destroying a brilliant vision just by facts :) > If you want a 32 bit z80 get a z380, it runs native z80 code, until you > switch modes then compatability works but it has a lot of gotchas. Net thing, but just 18 and 20 MHz types availabe - running as Z80 a 33 MHz Z180 might be faster (And never forget: you can't use R any longer as random number generator :). > If your doing a z80 stretch, you better think about how to access memory > or really alter the z80 fetch timing. Basic Z80 timing for say 20ns > memory would limit you to some 40-50Mhz... it would be a 5-10 MIPS machine > though. If you superpipline it and get it down to 1-2 clocks per cycle > you can double that. THe Z180 is already down to 3 cycle/instruction, and the z380 is down to 2 cycle/instr. But since the maximum clock rate of the 180 is more than 50% higher than the 280, it's the way to go. > In any case there is no way to logically stretch a > z80 without running the risk of making it software incompatable at some > point. I've seriously looked at it, still have the 2901s I was thinking > of using. I have z80/10mhz parts however and the 2901s would barely do > that. And if you try, most 10 MHz can run at 12 to 14 MHz. > FYI: z80S180s can be had into the 30+ mhz range. :) Jep and 1 Meg is still plenty of RAM when running CP/M But after all where is the sense of having a Z80 as 64 Bit processor ? It's a well usable 8/16 Bit processor. Even the 380 isnt realy an advantage - you just don't realy need this 32 Bit instructions. A set consecutive 16 Bit instructions can do it in almost the same time. From my point of usage a 16 Bit uP is anything you need - compact code, compact data and greater over all performance. Gruss H. -- Ich denke, also bin ich, also gut HRK

26 years, 2 months

More thoughts on building a Z-80 (64bit!!!)

by allisonp＠world.std.com

< I have looked at Z180's, Z380's and etc.... They are SLOW!!!!!! The < only availabe packaging for the Z380 is un-useable to me as a hobbist < (without a lot of headache.) Slow clock but they use fewer clocks and 16bit fetch. The effective speed is higher. Also the chip spped in climbing. The socket is a 25$ item to get from flat pack to wire wrapable. < I hate the way that Zilog has taken the nice and simple control bus sche < of the Z-80 and really made it a pain-in-the-butt on the Z-380!. At first I was of that opinion. Then I started with the z280 (Zbus mode) and z8000 and looked back at the z380 and it looks worse than it is. It's advantage is that it puts out advanced timing info making fast systems possible while using less bus bandwidth. < size set of bus control lines), Z-80 instruction set and match a DEC Alp < performance (at a cheap price of-course), I would worship that company. Why not find and Alpha and write z80 PALcode for it? < (Oh yes, I want a 64bit data bus and a 128bit address bus). Is this ask < for too much? Why can't we all just get along? You don't know why that isn't done. There are things about the z80 that do not scale well. < My thoughts are this: If I can find some REALLY SIMPLE mirco-controlle < that do just the basic microprocessor functions, I can parallel them to < make them read-in and intrepret Z-80 code. Like I said it's the sub 1nS memory that will stop you. A z80 at a theorhetical clock of 100mhz would require the memory *system* to have a M1 read cycle of less than 10nS. Try and find logic for decode and memory taht can make that happen in the required time. The Z80 bus provides little in the way of advanced timing to overlap operations so you need really fast memory and IO stuff. For example while z80s at faster than 10mhz are easy to get peripherals for greater than 8mhz are scarce and some never got faster than 4-6mhz! < and DEC Alpha) can reach clock speeds of 600 Mcyc and a really simple (o < accumulator, bare instruction set) microcontroller can't exceed those sp It's a study in piplelined operations. Simple machines have less to pipleine so the individual elements have to be faster. You cannot overlap as many operations as there only a few. Even with current superfast logic sub 1nS gates are rather scarce. So you hit the speed limit IE: how fast can you compare two numbers and branch based on the result. < If I got some of these micro-controllers and had two or three of them < reading in instructions ahead of execution (looking for branches) I coul < do half of the job and speed up the through-put. Except that they arent avalable that fast. Your trying to discretely do what a PII does internally. It's in esscence doing several things in parallel assuming some will be thrown away (branch no taken, add not done and so on) that take complex archecture so that you have more irons in the fire and can be more speculative. < For math, a bunch of stinking fast memory locations acting as look-up ta That works but to get the speeds you talking about where do these sub 3nS rams/roms come from? Can you wire them on a card so that the lead lengths are not a significant part of the timing (remember 1ft=1nS). These become real things when the clock exceeds 100MHz. I know this >from doing a 20mhz z180 design on paper and I was looking at fast cache rams chips to keep the memory inline, but for IO wat states were a must as most periperal chips I could find were limited to 10mhz bus speed range. I know I'm a party pooper but, I'm also one of those wacky engineers that has pushed the z80/z180/z280 to the edge and know what a design must do to work. On the other hand running CPM at 12.5MHz z180 is frighteningly fast but also points out system bottlenecks like disk speed! I've been putting time into overcomming that using disk caches and the like. Allison

26 years, 2 months

Y2K and immortal executables

by allisonp＠world.std.com

< >Ok, howabout a Brigeport milling machine with the PDP-8E it was purchas < >with in 1975, still running the same code. < < Sure, I can imagine that. But I can't imagine it will stop working < on January 1, 2000, or that the clock couldn't be set back to 1975 < without affecting the milling. Correction, what clock? Most control apps clocks are intervals, time between events, maybe time of day or week for longer periods and its rare that they even consider time of year. Keep in mind that until sometime past 1981ish clocks were not chips that kept time of day/year. Of ten they were a periodic interrupt that was totalized for time and date. So if the clock was broken it was software not hardware. The one example where Y2K has hit a PDP-8 use was a nuke power plant and the PDP-8 doing data logging had to print the right time date on the page. If the time and date were wrong nothing stopped working but the NRC would be upset with the dataing of the logs. FYI: Y2K happens to hit every 7-8 years on PDP-8 OSs as they only use 3bits for relative year. Bits used to be expensive! < If the source code has existed in some form since the late 50s or < early 60s, no programmer since its creation has tinkered with it? < I can imagine a slightly more plausible situation in which the source < was written in 1961, recompiled and tweaked throughout the Sixties, < and somehow the source was lost after recompilation in the Seventies < so only the executable remains, and that it's been running in some This is likely the commonplace event and the machine by the 70s was stable platform say like DG Nova, PDP-11 or other that has a lifespan exceeding 10+ years or still being made. Lost in some cases means it exists and somewhere on a backup that is in a room with 10,000 tapes of other backups that no one has looked at for 7+ years. Heck my vax archive is over 7 years old and is more than 20 TK50s. I don't recycle major backups as I've had tapes fail. So the deeper the archive the less likely the loss and also harder to find a specific item. This is only hobby use. business should do this far more often. < It's not that I'm denying Y2K - it's that I think it's overblown, < especially when it comes to antique computers. Me too. Many system Y2K is a singular event or non event. The only ones I even think about in relation to it are the PCs and maybe the VAXen (I run VMS 5.3 to 5.5). The PDP-11s may not like the date but most of the stuuff I do is not date centric so unless the OS breaks it keeps cranking. The PC makes me worry as DOS/Win and internetorking software may have bombs I don't know nor can fix myself. I've bumped the clock and it seems to behave though. Allison

26 years, 2 months

Emulation or the real thing?

by franke＠sbs.de

>> field fixings etc. Especialy in the /360.../390 world some >> of these routiens are older than the OSes where they are used >> today. Some are dated back to a thime when source was equal to >> punch cards - at this time only the object code was stored in >> libraries - source was stored as card boxes - and some of these >> little helper work just fine when used in complete new projects, >> 30 years later. > Good grief, you mean to say that these boxes of source code I have on punch > cards are finally going to be worth something :). Yeah - but fast, you have to finde s.o. in need of them :) <g> Gruss H. -- Ich denke, also bin ich, also gut HRK

26 years, 2 months

[off topic] Bomb Threat.

by DSEAGRAV＠toad.xkl.com

This is kinda off topic, but we've just had a bomb threat! No joke! Someone phoned in, asked for my boss, and said they put a bomb in the building! Why would someone bomb an ISP? Other than my boss is an Afican-American... (Native of Nigeria). -------

26 years, 2 months

[off topic] Bomb Threat.

by maxeskin＠hotmail.com

Well, I guess we see this trend of making things less redundant and less faithful to theory, more faithful to shaving off 1/4 of a cent universally. We see bomb threats pretty universally too, and not necessarily for political reasons. Are you sure it wasn't just a kid whose computer crashed again? > >> This is kinda off topic, but we've just had a bomb threat! >> No joke! Someone phoned in, asked for my boss, and said they >> put a bomb in the building! Why would someone bomb an ISP? >> Other than my boss is an Afican-American... (Native of Nigeria). >> ------- > >A sad commentary on a form of 'techno-terrorism' that is likely to become >more prevalent as dependency on the 'net' increases. > >The commercialization of the Internet has inadvertantly weakened one of >its major design points that was considered to be so critical when the >first ARPA designs were worked out. That being redundancy and lack of >centralization. > >Before the major commercial 'backbones' were in place, (set the 'wayback' >machine; Sherman) most systems had multiple shared dial-up connections to >numerous other hosts with which they regularly shared information (email, >news, files, etc.) > >If a network connection went down, (if you even had one) or a given host >was offline, traffic was just routed thru another system that indicated >connectivity to the system (or systems) that the traffic was destined for. >(everyone remember the periodic routing 'maps' that went around?) > >So... unless you lost ALL of your phone lines for an extended period, you >pretty much always had (some level of) connectivity. > >Today, on the other hand (generalization warning!) how many major systems >maintain dial-up inter-system capability even as a backup? > >The major infrastructures have tended to centralize around the commercial >'backbones' and carriers which make them succeptable to interruptions of >service when a single connection fails! (Sure... your web servers are fed >by dual 'T3s', but both from a single carrier thru a single POP?!?) > >So much in money and resources is often committed to create/maintain a >major (high bandwidth) link onto the net, (useful) redundancy is >frequently sacrificed. > >One attack on a major carrier POP (ok, definition time: POP = Point >Of Presence) could easily disrupt Internet traffic for a LOT of people and >corporations. > >Take out a couple of the major authoritative DNS servers, and watch the >world (generalization) start crashing down! > >Or sadly, target one ISP that is suspected of being a major provider? > >It happens... more often than you might ever imagine... > >-jim >(I speak for no one but myself... YMMV) >--- >jimw(a)agora.rdrop.com >The Computer Garage - http://www.rdrop.com/~jimw >Computer Garage Fax - (503) 646-0174 > > ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com

26 years, 2 months

Building a Z-80 (64bit!!!)

by allisonp＠world.std.com

< THe Z180 is already down to 3 cycle/instruction, and the z380 is < down to 2 cycle/instr. But since the maximum clock rate of the < 180 is more than 50% higher than the 280, it's the way to go. No news to me. I'm running a modifed SB180 (z180) and also working with z280/12.5Mhz. I've looked at z380. < > of using. I have z80/10mhz parts however and the 2901s would barely d < > that. < < And if you try, most 10 MHz can run at 12 to 14 MHz. I've taken the 10Mhz part to 12.5Mhz. < < > FYI: z80S180s can be had into the 30+ mhz range. < :) Jep and 1 Meg is still plenty of RAM when running CP/M That it is. < But after all where is the sense of having a Z80 as 64 Bit < processor ? It's a well usable 8/16 Bit processor. Even the < 380 isnt really an advantage - you just don't realy need this < 32 Bit instructions. A set consecutive 16 Bit instructions Larger flat address space. The z380 would make a real good data handler (z382 is a PC bus slave version for comms) or possibly a graphics crunchers. Even in the z80 native mode you can access beyond the 64k basic addressing in a manor that is more convenient than the basic z80 provides. In most cases the extended mode changes the the effect of the arithmetic overflow in 16bit ops so that 0FFFFh+1 is not 0000. but 10000h. There are of course extended operations as addressing modes as well. < can do it in almost the same time. From my point of usage < a 16 Bit uP is anything you need - compact code, compact data < and greater over all performance. Z380 still has those attributes. It saves the memory management overhead for apps that need to get at spaces larger than 64k. I plan to do a bit of serious work with one if I can get my hands on a few and a socket adaptor. Allison

26 years, 2 months

Emulation or the real thing?

by franke＠sbs.de

> This reminds me of a claim I hear in Y2K discussions, but can hardly > believe: that businesses are running the same *executables* since > the 1950s/60s/70s, and that they don't have the source code to fix it. In fact, this is widely true - Ok, the most cases are not about the source of the whole programm or the main programm its more about subroutines that have been used over the years to solve common things like conversation, key transformations field fixings etc. Especialy in the /360.../390 world some of these routiens are older than the OSes where they are used today. Some are dated back to a thime when source was equal to punch cards - at this time only the object code was stored in libraries - source was stored as card boxes - and some of these little helper work just fine when used in complete new projects, 30 years later. > Sure, they might not have the source to the OS, but their own apps? Remember 30 years - have you ever archived all your work for 30 years ? _EVERY_ Programm you did within these 30 years ? > And that there's been no other reason to change or replace the > programs in all these years, and Y2K is the only reason they need to do it? Jep it is - for example lets take a common old application, for example a salery programm for a big company - the programm still uses the same algorythms since 30 years - the same way of I/O and the same basic data - just some modules for tax calculation have been changed over the years. After all I bet some of these programms will even survive the Y2K hype without change :) Gruss H. -- Ich denke, also bin ich, also gut HRK

26 years, 2 months

Fwd: secrets of a microvax II

by Mzthompson＠aol.com

Following is a usenet posting from a guy needing some help with a uVAX II. It sounds like what I would call a basket case, he hauled it home in several baskets in this case. I have emailed him answers to the more basic questions. Since there are a few of you with far more knowledge on this, I thought maybe some of you could help him out. My knowledge of the uVAX II is limited to having gutted out 6 machines being disposed of by former employer. Sorry, that was before I knew of Classiccmp, snif, snif. Mike Please email directly to him. Subject: secrets of a microvax II From: siebert(a)berlin.gmd-net.de Date: Thu, Oct 22, 1998 07:39 EDT Message-id: <70n5h7$koq$1(a)nnrp1.dejanews.com> Hi there, I need help... I got a DEC Microvax II System which is partly disassembled and has the following coponents: ------------------- | | ------------------- | <OO> | < > | 1) looks like a kind of harddisk ------------------- | < ..I>| 2) MICROVAX II | < ..I>| ------------------- | < . >| 3) ? with a TK50 tape unit | < . >| ------------------- | | 4) RA81 harddisk | | | | | | ------------------- | | 5) power supply ------------------- 1) The harddisk (?) is perhaps from FUJITSU and there is place for a second one. It has to be connected to a EMULEX QD 331040100 controler. I saw some pictures of the same units on the web! 2) The muVAX II processor has no harddisks or any drives and has one switch, four buttons and two LEDs on the front panel. It has the following boards: (back view, top) ------------------------------------------ | M 7606 KA630 CPU | ------------------------------|||||||||--- | M 7608 4MB Memory | ------------------------------|||||||||--- | M 7608 4MB Memory | ------------------------------------------ | |M 7504 DEQNA Ethern.|--cable ------------------------------------------ | | ------------------------------------------ | | ------------------------------------------ | | ------------------------------------------ | | ------------------------------------------ 3) The other housing looks like the muVAX processor but has only two buttons and the built in TK50 tape unit. It has the following boards: (back view, top) ------------------------------------------ | M 9404 connector | |-- cable to muVAX II ------------------------------------------ | M 3104 8 line serial controler |-- cables ------------------------------------------ | M 7546 TK 50 ctrl.| |-- cable to TK 50 ------------------------------------------ | M 7164 QDA processor for KDA 50 |-- cables ----||||||-----------------||||||--------- | M 7165 QDA SDI controller KDA 50 | ------------------------------------------ | | ------------------------------------------ | | ------------------------------------------ | | ------------------------------------------ 4) RA 81 456 MB SDI HDD 5) power supply digital 874-F On the backside are the following connectors: > 8 serial 25 pin SUBD connectors > 4 connectors for SDI drives > 1 DEQNA Ethernet 15 pin SUBD connector with a fuse > bulkhead with 9 pin SUBD console connector I have no documentation except from the manual for the serial controller... Hmm.. now I have some problems/questions...: - Which was perhaps the use of this system ? - which was probably the OS (Unix version...) ? - Was it a single user system ? - where can I get a "user handbook" for the muVAX (booting, meaning of the front buttons of all components...) ? - Which type are the housings for this muVAX (BA23, BA123...) ? - Why is this muVAX II SO BIG ??? (in comparision to the "under table systems" which don't have TWO boxes for the cards...) - What is the difference between a Microvax II and a Vaxstation II ? I have no Terminal to use as console - what kind of connector is the 9 pin SUBD connector on the backside (bulkehead) ? - What kind of terminals can I connect ? (I have some SS97 Siemens Terminals or a IBM colour Terminal...) - Can I use a PC with a TTY or a VT100 emulation and a serial connector cable ? - Do I have to use always a console to start the system (with a switch on it or something like that) ? Some of the cards are disassembled in the machine - Where in the muVAX processor housing 2) must I plug in the M 9404 card coming from the "controller housing" 3) and which side must be on the top ? - Where in the "controller housing" 3) must I plug in the EMULEX controller (it needs only half of the place) ? I am not firm with RA81 HDD - Where in the RA81 must I plug in the flat connector ? - Is only one of the four flat connectors for ONE RAxx drive ? - what are the two round mini 4 pin din connectors for in the RA81 ? - in which of the four flat connectors on the back of the system do I have to plug in the RA81 ? - Is there any information about the SDI "standard" ? In both the processor and the controller housing are slots for connecting HDDs. - Do I need controllers for connecting drives there? - Is it MFM standard ? - When there are no drives in it, do the buttons on the front panel have any function ? General... - How can I use the Ethernet connector (compatibility, wiring...) ? - What is the power supply for ? (one big INPUT, three OUTPUTS - all 220 V and 4 smaller outs !) - from which of the two harddisks (RA81, FUJITSU) does the system boot from ? - What are the 8 serial connectors for (Terminals...) ? - For which use was the TK 50 tape for (booting, streamer...) ? I also got a DEC VR262 screen together with the whole stuff, but I can't imagine that there is any use with the muVAX. - how can I use the VR262 ? I know this are manymanymany questions, but even few ansers would be a great help, thanks - Rainer

26 years, 2 months

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test-drb October 1998