test-drb October 1999

test-drb@ccmp.vtda.org

216 participants
748 discussions

by pete＠dunnington.u-net.com

On Oct 24, 21:48, Marvin wrote: > Richard Erlacher wrote: > > Has any of you ever encountered an approach to this that could be managed in > > the home environment with equipment costing, nominally, less that a k-buck > > or two and achieving nominally 10-mil traces with 8-10 mil separation or > > anything close to that? How about a dry-film solder mask? > Doing the process at home can be done with a minimum of equipment if service > shops are used for parts of the process. A small copper plating tank, > tin-lead tank, and peroxide-sulfuric etchant along with fusing oil and flux > can be set up at home for probably a couple hundred dollars. To set up a > fairly complete shop including drilling and imaging would probably cost > between 2K and 3K. This would provide the capabilities of producing > reasonably high quality boards. Oh, did I forget to mention getting the > experience to know how to do it :)? I've never done the full process Marvin describes at home, but there's a commercial website that has quite a lot of useful information. Eniough to encourag me to try it "one day": http://www.thinktink.com/ (If you're like me, and keep that Java(script) stuff turned off, turn it on for this site, as the menus need it). -- Pete Peter Turnbull Dept. of Computer Science University of York

24 years, 8 months

Radio Shack TRS-80, Model 1

by blrab＠digisys.net

I have a TRS-80 Model 1. The monitor is third-party, the disk drives are third-party. I have all the documentation, plus NEWDOS 80. Not wanting to trash it (chuckle), do you have a home or where's the best place to post this? The machine is in NW Montana. I can't pay for shipping, although I will pack it carefully for shipping. In other words, the machine is free, FOB Polson, MT. Any ideas? Bob Bushnell blrab(a)digisys.net

24 years, 8 months

OT: how big would it be?

by Philip.Belben＠pgen.com

> Of course you could, but why would you want to? What's the problem with > PCBs (or am I going to find out for myself when I get seriously into > making them at home?) Nothing except that I thought they were a more recent innovation. I was thinking along the lines of, this is how you might build it with technology available in 19XX Can anyone give a timeline with (a) the invention and (b) the first commercial availability of: PCBs, Transistors, ICs (perhaps divide up by technology and scale of integration), and possibly other items of technology relevant to this period (say, 1940 to 1970)? Along similar lines, what multipin plugs were available at what date? In the 1930s and 40s, multipin plug and socket often meant something that plugged into a valve (tube) base... Philip. This E-mail message is private and confidential and should only be read by those to whom it is addressed. If you are not the intended recipient, you are hereby notified that any dissemination, distribution, copying, reproduction, modification or publication of this communication is strictly prohibited. Please delete the message from your computer and destroy any copies. This message is not intended to be relied upon by any person without subsequent written confirmation of its contents. This company therefore disclaims all responsibility and accepts no liability of any kind which may arise from any person acting, or refraining from acting, upon the contents of the message without having had subsequent written confirmation. If you have received this communication in error, or if any problems occur in transmission please notify us immediately by telephone on +44 (0)2476 425474

24 years, 8 months

XXDP help needed

by pechter＠pechter.dyndns.org

> In article <7v20se$i4n$1(a)info.cs.uofs.edu>, > Bill Gunshannon <bill(a)cs.uofs.edu> wrote: > > Can anyone give me a rundown on the commands needed to use ZRQBC1 > > to format an RD52?? > > > Is there docmentation available anywhere for XXDP?? People always > > tell me UNIX is too cryptic, what would they say if the saw XXDP?? > > I wonder what extent DEC's naming conventions led to their ultimate > downfall? Once you're used to it you can tell a LA120 from an RZ28 and > a KZPCM-AA from a FRPG4-WI, but damn... > > -- > In hoc signo hack, Peter da Silva <peter(a)baileynm.com> > `-_-' Ar rug t? barr?g ar do mhact?re inniu? > 'U` <pfy> Sigs with pfy's markov chain. > -- "pfy", a markov chain IRC bot. Is my memory of the breakdown of the diags correct? +--> Diag software | +--> Second diag | | ZRQBC1 | | | +-->Revision C patch level 1 +--RQDX? disk controller (does the R stand for Rotating Memory Here?) Always found DEC's PDP11/Vax naming conventions made more sense than IBM's or HP's. (Except for the DL/RL/DM/RM/RK issues with boot rom input vs. drive names...) And their diag supervisor xxdp diags were much easier to deal with than almost anything else. (I loved the early xxdp stuff you had to deposit to constant locations to change the seek/read-write timings). Bill --- bpechter@shell.monmouth.com|pechter@pechter.dyndns.org Three things never anger: First, the one who runs your DEC, The one who does Field Service and the one who signs your check.

24 years, 8 months

IBM 5155 Anyone have one?

by roblwill＠usaor.net

Hi! Does anyone have an IBM 5155 (I think I got the model right) Portable PC that they would want to sell/trade something for? I'm trying to narrow my collection down to portables, since I sorta have limited space, and I may be getting rid of (probably on the list) some of my desktops. -Jason (general-one(a)home.com)

24 years, 8 months

gauging interest in VAX 6000-530

by allisonp＠world.std.com

<My main belief is that nobody is going to keep a VAX anything running with <dozens of simultaneous users. So, if a VAX is to be something close Very errorloaded belief. It's done, being done. In 1993 the style of computing is actually quite different than current. large companies used VAX or as400 as central computers and maybe also servers to those PC users that wanted application autonomy. <Now, perhaps if we were to port Apache to the VAX, and used that I/O bandwi <on multiple DS3s, well, that's great. Exists, I know of a company using a bunch of 6000s to service a user base of some 1000 systems never mind running all the batch jobs like payroll, job costing, database updates and other mundane stuff. <Hey, I'm not saying the original IBM PC was going to outperform the VAX 650 <but a modern PC will crush any VAX in any application, IMHO, with equivalen <h/w attached. NO, simple reason, PCs don't have equivelent hardware. <1) The names of these busses? Some are FDDI, Massbus, CI, HSI, SCSI(I/II/IIW...), and a few properitory busses. <2) Their uses? Two general catagories, memory interconnect and Storage interconnect. There are several IO interconnects as well. <3) Their peak and average throughputs? I think FDDI is still in the 100++m/bytes/Sec region. Though there were a few parallel busses that were 50-100mbytes/sec rate. I will not argue this as PC are finally going fibre and Gigabit eithernet but thats 10 years after the fact. <I certainly know for a fact that UNIBUS performed very poorly. I don't hav <data at my fingertips, but it seems to me it was around 10 Mb/s (that <megabits/sec) peak throughput. [I prefer measuring throughputs in bits/se <since that normalizes across different bus widths.] Also loaded with errors. Systems process things in chunks. FYI the pdp-11/70 was a 1mips (I think it was also 1mfps) machine despite that slow unibus. <Fast dual-port SRAM solves the problem, but commodity PCs aren't designed <that way. Also, the AGP bus uses mega-RAM to speed up PC graphics, for exam Exactly they arent designed that way. The cpus might do better in a real system but even then there are throughput issues. Your original arguement WAS a 486dx would kill the VAX 6000-530. the answer is still not ever! In the end it still takes 10k$ to do what 10k$ of vax did then. The rather specious arguement of my daddy can beat your son is is pointless. I can easily beat a PDP-8 with a slow PDP-11, what have I proved other than the next generation machine is better (wasnt that the point of its design?). In 1993, PCs were plentyful but they were not the applications killers. What they were then was the cheap workstations with 640x480x8 or maybe 800x600x8 graphics and often a lot less. Could a 486dx be made such that it would be a crusher box... yes but, there would have been no software for it as PC compatability was a must have back then other wise it was just another soso cpu. Allison

24 years, 8 months

Calculator Comparisons

by allisonp＠world.std.com

<Of course you can. The exact details are a right fiddle (partly because a <nixie tube is not a diode, so you are going to get sneak paths!), but <basically you sequence the anodes of the tubes to the B+ rail and then <ground the appropriate cathode for each tube. Nixi is a threshold device so there are no sneak paths but the actuation voltages are pretty fussy due to the hystersis. <A _lot_ of calcultors had a multiplexed nixie tube display. It was much <less common in test gear which is why I guess you've not seen it. Really, never saw many that did, the vacuum florescent (bluegreen) were generally mux'ed.. <You want to look at the 7441, and 74141. I seem to recall there being a <TTL chip with counter, latch(?) and nixie driver all in one package. I <can't remember the number but it was a 7414-something (74142/74143???) 74142 is the nixi (Counter, latch, decoder) and the 143 is the led/lamp seven segement. 74141 is an pmproved 7441 and likely easier to find. <And no, they don't seem to be in the more recent TTL databooks I have <here :-(. I think there are still plenty about (if only in the junkboxes <of people on this list :-)) My Ti data books have them (ca1976) as do the reference TI set from the mid 80s. I'd expect they can be found easily enough. Allison

24 years, 8 months

DOS 1.10

by allisonp＠world.std.com

<Has anyone else run into trouble reading 8 sector disks under Win95? I trie <to read the IBM DOS 1.10 disk and just ran into the Abort, Retry, Ignore <error message. When I booted it up and copied it to another disk on the <Compaq luggable, everything worked out just fine. W9x driver assumes default formats. use a dos box to copy the contents of the disk to a format the winbox knows. FYI: Don't bother win9x in dos mode as it's still the same drivers. Allison

24 years, 8 months

gauging interest in VAX 6000-530

by ethan_dicks＠yahoo.com

--- Sean 'Captain Napalm' Conner <spc(a)armigeron.com> wrote: > One of the stories about the machine relate to a package that just showed > up one day. They open it up to find a replacement fan for the machine. It > seems that the machine in question had determined that one of the fan units > was marginal and had placed an order for a new one from the manufacturer. Tandem's do that. They used to print warning messages on the console that failover had occurred, but people got out of the habit of reading the logs. The solution: bypass the customer and order parts directly from the vendor when faults were detected. Most customers learned that something failed when a) a part showed up or b) a field-service engineer showed up. -ethan ===== Infinet has been sold. The domain is going away in February. Please send all replies to erd(a)iname.com __________________________________________________ Do You Yahoo!? Bid and sell for free at http://auctions.yahoo.com

24 years, 8 months

Benchmark Wars (was Re: gauging interest in VAX 6000-530)

by cmcmanis＠mcmanis.com

At 04:01 PM 10/24/99 -0700, Mike wrote: >(Hi Chuck!) > >Here's my back-of-the-envelope: [snip] Ok, you've considered the memory bandwidth without considering: 1) That disk transfers also happen across this bus. 2) Other I/O (mouse? Sound? Video?) 3) The interrupt load on the CPU. As an empirical note the 16450 UART often could not be serviced fast enough by the 486DX66 to prevent it from dropping incoming characters above 9600 baud. That was even with the "FastCOM" driver that came with Procomm plus for DOS, not until the 16550 added a 16 (or was it 32) character FIFO did it work. Now multiply that by 12? Say 9600 baud, every types a key. That is 12 interrupts to service while you're potentially trying to push out 12 streams of bytes. Anyway, the VAX (and most DEC gear) got around this by having channel processors _everywhere_ and of course the modern PC has channel processors _nowhere_. (IDE taking this to the logical extreme) Somewhere I've got an 8 port serial card that was built for the 16 bit ISA bus (it has 8 mini-din connectors on the card edge). The thought was to run UNIX on a 486 and use terminals for multiple students. It didn't work. The PC couldn't keep up. I fully admit though that given source code I might have been able to make it work :-) --Chuck

24 years, 8 months

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test-drb October 1999