test-drb November 2007

test-drb@ccmp.vtda.org

229 participants
508 discussions

by ajp166＠bellatlantic.net

> >Subject: Re: *updating* 8088's > From: Ray Arachelian <ray at arachelian.com> > Date: Mon, 26 Nov 2007 13:15:02 -0500 > To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> > >Roy J. Tellason wrote: >> On Friday 23 November 2007 19:05, dwight elvey wrote: >> >>>> From: rtellason at verizon.net >>>> >>>> I notice that even those guys that are building relay computers "cheat" >>>> and use a single small solid-state chip for RAM. :-) >>>> >>> Hi >>> I've been thinking about how one could make a reasonable >>> memory, using small reed relays. If one puts a magnet close >>> to one end, it will cause the reed to close. Move it back >>> some and it will hold until the field is too weak. >>> >... >> >> Dunno if they still sell them or not, but Radio Shack used to sell a pack of >> 20 reed switches for only a couple of bucks... >> >> > >Hmm... Wonder if it's possible to build a relay without a spring on the >switch. That is, you have to send current with one polarity to set the >switch to a 1 and reverse polarity to set a zero - sort of what core >memory does with rings... I suppose this could instead be done by >attaching a magnet to the switch, or using magnet as the thing inside >the switch body, or better yet maybe a relay with a ball with a set of >contacts as the switch and two magnets, one on each opposite side... >you'd energize one coil for a "1" and the other for a "0" > >Hmm, could even be done with a solenoid and use the mechanical part of >it to touch a wire for output. :-) Wouldn't really be a relay, but >pretty close. Telco stepping switches. I have a few. Also you can get small relays that are dual coil, one to set and one to reset. Widely used in automatic antenna tuners to select L and C as needed to resonate an antenna for most any frequency. The idea of a latching relay is once set no more power is needed. Allison Allison

17 years, 4 months

OT : CRT replacement

by cctech＠retro.co.za

Hi all Apologies for the off-topic, but I'm pretty sure someone here knows the answer to this one. A friend has a Motorola Communications Analyser model number R 2001 B. The CRT is blown. I don't even know if it's vector or raster, I'd suspect vector? Picture at http://www.econ2way.com/cgi-bin/service_monitor_display.cgi?site-images/Mot… Any idea where I can scrounge a replacement CRT, anyone? Thanks W

17 years, 4 months

Cold booting an Apple III ?

by jos.dreesen＠bluewin.ch

Is there a way to coldboot an apple III, if you do not have the SOS disks ? On the apple II you can do it via the serial interface and the Basic ROM, but the apple iii lacks these ROM's Jos DReesen

17 years, 4 months

Classic Computer Stuff Auction - More Items & Pictures Added

by ggama＠coakleytech.com

Do you still have the Trace 5 5 1/4" duplicator? Thanks, George

17 years, 4 months

PCKeybaord keytops

by cclist＠sydex.com

Last week, someone pointed me to Ergonomics Resources a source for decent PC keyboards, such as their version of the old Northgate unit. I voiced a concern about a pet peeve of mine--that the keytops would be the everyday surface-marked ones, rather than the old double-shot ones (which have legends that are almost impossible to wear away). Here's the response I received: "Thanks you for visiting our web site. The Stellar is in most ways like the Northgate keyboard you used many years ago. But they too have gone the way of Laser engraved key tops." "We do still have some (new in the box) Northgate Evolution Keyboards (split keyboards) that have the double injected keycaps if you're interested. " http://www.ergonomicsmadeeasy.com/index.asp?PageAction=VIEWPROD&ProdID =12 I guess I'll stick with my Model M. Cheers, Chuck

17 years, 4 months

IBM 4019 Laser Printer

by rtellason＠verizon.net

I have one of these, and it seems to be a real workhorse, as is evidenced by the status page it kicks out on powerup, which lists somewhere close to a quarter million pages having been printed out... That status page is a part of the problem. When I got it I was told that "a postscript board" was in it, and it indeed does seem to speak postscript just fine, but as long as I have that emulation enabled (as opposed to LJ or whatever, I think there were three or four choices altogether) it kicks out that page every single time you power it up. Is there any way to defeat this? Also, since I switched to using this LJ5 I acquired fairly recently, on pulling the paper out of the IBM it seems that a roller that sits on the top of the stack of paper is in the process of turning to goo, like those capstan rollers I see mentioned in here from time to time. Is there a rebuild kit or are replacement parts for this thing available out there anywhere? -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin

17 years, 4 months

PDP-11 comm stuff (and more) from a haul available

by henk.gooijen＠hotmail.com

Hi all,Last week I hired a truck to pick up a "few" things ...- H960 rack with PDP-11/45 and a Cypher 100 tape drive ("not working" sticker attached to the Cypher)- H960 rack with PDP-11/55 with 28k fast memory (according to the post-it attached to it)- H960 rack with TU45 ("seems complete" says the post-it)- H960 rack with TU16 (capstan rooler is goo)- H960 rack with communications stuff (see below)- two RK07 disk drives- RM03 disk drive- RM03P disk pack with diagnostics- two DECprinter I- DECwriter II- cabinet with SYSTIME SYSTAPE II unit (capstan also goo)- a few boxes, one contains a complete RH11-AB- RT-11 V5.4 SRC micro fiche (#1 - #86) in two envelopes complete with the Bill of Material!- complete RT-11 V4 manual set in blue binders- complete RT-11 V5 manual set in orange bindersNeedless to say that my wife was not so glad when I got home :-)I took pictures while unloading, and they will be on my website,probably a good moment to do that are the Xmas holidays ...I plan to get rid of most of this, and use parts to get otherunits in my collection restored into working order. The 11/45will go to Edward, the 11/55 is a great addition to my UNIBUSmachines collection.Most of the stuff will probably be too heavy to ship ...I disassembled the BA-11F with the comm stuff. The completepower harnass is for whom it wants/needs. I can take pictures.The BA11 contained two DR11-B 4-slot backplanes, populated withM7219, M208 (2x) M7821, M796, M205, M^11 (2x) M112, M113, M239and an M9680 DR11-B test connector board, power 'paddle' board,and connector board M9760 with two cables attached to it withon the other end one connector board (single height) M908?That single height connector board went into a small rack-mountunit with a 2-row backplane containing the folowing boards:M5950 (8x), M3020 (3x), M205 (5x), M111, M112, M306, M611 andone onit has M113 (3x) and the other unit has M113 (1x) andM1131 (2x). One unit was marked "RX", the other was marked "TX".On the side of the backplane is a label with this text:DIGITAL CSS P/N 2M-C121A S/N NU00001 DX40AB.The other unit has the same lable, but S/N is NU00002!Each unit has its own power supply, H716A.I elaborated a bit more about the comm stuff, because I reallydon't have a use for it, unless dismantling it. So, if somebodywants this (DR11-B or DX40 or everything), let me know.I have no idea what the things weigh, so neither do I know whatthe shipping costs would be. Free pick up in The Netherlands :-) allthough recovering some money from hiring the truck would be nice.I am also looking for two buttons of the TU45. They are damaged.It's the lower two on the control panel, "FILE PROT" and "1600BPI".thanks,Henk

17 years, 4 months

OT : CRT replacement

by dm561＠torfree.net

Date: Mon, 26 Nov 2007 11:43:08 +0200 From: Wouter <cctech at retro.co.za> Subject: OT : CRT replacement >A friend has a Motorola Communications Analyser model number R 2001 B. The >CRT is blown. >I don't even know if it's vector or raster, I'd suspect vector? >Picture at >http://www.econ2way.com/cgi-bin/service_monitor_display.cgi?site-images/Mot… >Any idea where I can scrounge a replacement CRT, anyone? >Thanks >W -------------------- If your friend is sure it's the CRT he/she must have had it apart; what's the number, size, etc.? m

17 years, 4 months

Documentation for the AT&T Sceptre Videotex terminal

by dm561＠torfree.net

-----------------Original Messages: Message: 29 Date: Wed, 21 Nov 2007 07:15:37 -0800 (PST) From: Cameron Kaiser <spectre at floodgap.com> Subject: Re: Documentation for the AT&T Sceptre Videotex terminal > But see, it HAS to be bad if Microsoft does it. One little key, and > the keyboard universe falls apart. I believe the objection was its placement, not the presence of a Windows-specific key. I've certainly had trouble adjusting to a Windows keyboard after being used to not having anything between Ctrl and Alt. Even Macs don't disturb that. Command is to the side of that group, not splitting it up. ------------------------------Reply: Well, yes, obviously the location is the issue, but it is still just another tedious MS-bash; I've got an APL keyboard here, and I think every "classic" terminal or computer keyboard I have here is different in some "improved" way but I don't hear complaints about that, or all the different PC layouts, especially the enter, backspace and \ keys. I find the WIN keys quite handy, and since they're control-type keys the location actually makes sense to me; just part of the DOS>WIN adjustment. Don't you also have trouble switching from a C64 to a Mac? m

17 years, 4 months

Teaching kids about computers...

by dm561＠torfree.net

--------------Original Messages: Date: Fri, 23 Nov 2007 12:58:17 -0500 From: "Roy J. Tellason" <rtellason at verizon.net> Subject: Re: Teaching kids about computers... On Thursday 22 November 2007 18:48, Chuck Guzis wrote: > Good point. There is the concept of "depth" of understanding. Many > people who regard themselves as programming professionals would be > lost without an operating system. Some would be lost without an > assembler. And, sad to say, some would be lost without some sort of > Java facility. This reminds me of folks I used to run into back in the day that considered themselves "programmers" -- in dbase! > For some, that's not sufficient. Understanding how a disk drive > works or what goes on over a TCP/IP connection is essential to them. Some of us actually enjoy that sort of thing and some just want to be able to use the end result, or maybe tweak it a bit. ------------Reply: Well, you've just insulted several thousand professional dBase programmers, myself included, with your elitist snobbery. I would guess that a competent dBase programmer would probably have the average small database program completed and delivered in the time it would take just to lay out, code and debug the necessary file- and screen-handling routines in most of the other comparable languages of the day, at least until you'd built up a decent and relevant library. Tools are developed to make a job easier and do it better; in my opinion taking advantage of those tools and doing things "the easy way" makes you more professional, not less. A programming professional's job is to deliver a product that meets the client's needs, is well documented and easily maintained, and is delivered on time and within budget. Knowing or caring about the arcane details of a disk drive or being able to program an OS-less computer in binary may matter if you're working on an embedded controller but it's pretty irrelevant if the project is a client accounting system for a large financial institution. What is important is good communication and organizational skills, the ability to conceptualize, proficiency in the use of whatever tools are appropriate to the job at hand, and enough humility to give the client what he/she really wants instead of what he/she *should have*, qualities often lacking in the "hacker" mentality. The same applies to the original topic: among the many replies suggesting how a child *should* learn about computers, I didn't see many suggestions that the child him/herself might be the best judge and perhaps the best approach might be to explore what his/her interests are (instead of what yours were), and provide whatever resources are appropriate and relevant to those interests. m

17 years, 4 months

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test-drb November 2007