test-drb

test-drb@ccmp.vtda.org

101090 discussions

Connecting SGI GDM-20E21 to SPARCstation 2.

by trasz＠FreeBSD.org

I have the following: SPARCstation 2 with GX card (1M mappable, rev 7), SGI GDM-20E21 monitor (Trinitron, OEM from Sony) and 13w3 cable. Obviously they don't work together - the pinouts are said to be slightly different in SGI and Sun. Now, is there any easy way - cut some wires, connect the others - to make this work? -- If you cut off my head, what would I say? Me and my head, or me and my body?

18 years, 9 months

Need a sanity check

by allanh-cctalk2＠kallisti.com

On 14 Sep 2007 at 9:41, Chuck Guzis wrote: > I'd appreciate it, Glen. Only the handshaking lines (IFBY, IDBY) > need be buzzed out, I think. The tape motion commands seem to work > just fine, but reading or writing moves the tape without the driver > returning (i.e. stays busy). I built my cable from an Overland > description, so I'm not completely sure that it's correct. I buzzed out my Overland cable some time ago, and just checked the handshake lines above against the reference you used. They match. For reference, my cable wiring is at: http://www.kallisti.com/~allanh/misc/overlandperteccable.html allan -- Allan N. Hessenflow allanh at kallisti.com

18 years, 9 months

Computer rescue

by wmaddox＠pacbell.net

Hi, folks. A few weeks ago, I sent out a last-minute request for help with a large computer rescue on the east coast. As was not entirely expected, no one was able to make it on such short notice during the week, however all worked out well in the end. I have some pictures of the "haul" as it arrived in San Jose up at www.ddp116.org . --Bill

18 years, 9 months

GPS chipsets

by steve＠radiorobots.com

Hi All, Looking for GPS chipset docs from late 80s to early 90s. Maybe Thales, Sokkia, Javad, JRC, Trimble, Rockwell, etc? Any responses appreciated. Thanks, Steve

18 years, 9 months

Kaypro movcpm.com

by redodd＠comcast.net

Hello Kaypro fans, I'd like to put a Kayplus83 rom into a Kaypro II so I can add double sided drives and have all the other nice stuff that the rom provides. It's the early model with an 81-110B1 motherboard that needs the wiring for the floppy side 2 added. The Advent Turborom manual has the wiring mods needed for side 2 access. The Kaypro II comes with a 2K eprom and the Kayplus83 is an 8K. Again the Turborom manual tells how to access a 4K rom and adding access to the A12 line should make the 8K rom work. I think that I've got that part all worked out. To make the Kayplus boot disk, you have to have a system size of 62K or smaller. My Kaypro II disk has a 64K system. When I run movcpm.com to change the system size, the program hangs. I also tried the version of movcpm that comes with the Kaypro 4 and that hangs also. So question (1) is, has anyone gotten this program to work or is there another easy way to do this? There's a blurb on the net about the Kaypro 1 movcpm not working right but I didn't see anything about the Kaypro II version. Question (2) is, should the movcpm program from another Kaypro model work on a II or are they all specific to 1 model. TIA. Ralph

18 years, 9 months

Fwd: [Electronics_101] On this day

by rtellason＠verizon.net

---------- Forwarded Message ---------- Subject: [Electronics_101] On this day Date: Thursday 13 September 2007 18:05 From: Bruce <hvekybd_willtrav at bellsouth.net> To: Electronics_101 at yahoogroups.com From Wikipedia, 1956 <http://en.wikipedia.org/wiki/1956> - IBM <http://en.wikipedia.org/wiki/IBM> unveiled the 305 RAMAC <http://en.wikipedia.org/wiki/IBM_305_RAMAC> (Random Access Method of Accounting and Control), the first commercial computer <http://en.wikipedia.org/wiki/Computer> that used magnetic disk storage <http://en.wikipedia.org/wiki/Hard_disk_drive>. http://en.wikipedia.org/wiki/IBM_305_RAMAC Though this would be interesting. Just one of the large boxes in the picture, hold almost as much as a DVD does today. Just show how far we have come. ------------------------------------------------------- -- 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

18 years, 9 months

More stuff in Pasadena-Arcadia

by dgriffi＠cs.csubak.edu

The chap I told you about earlier with the Nova 4 still needs some help paring down his oversized collection. I will be down there tomorrow (Saturday) to pick up the last of what I'm selling for him. There still is a lot of early PC-related things, ham stuff, telecom crap, and miscellanous miscelleny. Is there anyone out there who's willing to spend this Saturday helping him clean up things? Anything that doesn't get hauled away will otherwise get hauled away by the e-waste disposal people. And they aren't kind to vintage stuff. So, if this sounds like your idea of fun, email me at the below email address or my yahoo account (username: cupricus) and we'll get things set up. -- David Griffith dgriffi at cs.csubak.edu

18 years, 9 months

MicronEye camera software

by shieldsm＠gmail.com

I just picked up a MicronEye camera "for IBM PC" - it came with everything except manuals and software. "Everything" means: The camera itself (with a ribbon cable out) MicronEye controller box of some sort, ribbon input and RJ12 output 8-bit ISA paddle with RJ12 input. A cardboard washer taped to a piece of paper labeled "CLOSE-UP RING" (and original box to boot!) The ISA paddle has an AMI S68B50P IC (a serial interface I believe) and some 74LS parts to glue it to the ISA bus. This leads me to believe that the camera controller box itself speaks serial to the ISA board. I know from some googling that this camera was often featured connected to early Macintoshes, and the box it came in indicates it was available with interfaces to Apple II, TI, TRS-80 CC, Mac, and IBM PC. I guess I'm looking for any info on how I might obtain software for it - really any software for any of the platforms would be helpful -- or even just pointers as to how it might be programmed against. As well, I might be interested in adapting it to hook up to a Mac SE or the like, as working with pictures (especially the black-and-white pictures I believe the camera is capable of producing) would be a bit more natural on the Mac SE than on an age-appropriate PC. There were some references to this device in the cctalk archives - it seems others out there have these things. It also seemed like there were some kits or third party producers of cameras based on the Micron ram chip, but this is an "official" Micron product. Well, thanks for any pointers! Mike

18 years, 9 months

21" CRTs (St. Louis, MO)

by legalize＠xmission.com

Big piles of 'em. For all of you who were saying how you much prefer CRTs, this might be worth pooling up and splitting a lot. These will probably be cheap to purchase, but $$ to ship. (37) Asstd 21" Computer Monitors <http://www.dovebid.com/assets/display.asp?ItemID=cpt67356> (14) Dell P1130 21" Computer Monitors <http://www.dovebid.com/assets/display.asp?ItemID=cpt67336> (27) Dell P1130 21" Computer Monitors <http://www.dovebid.com/assets/display.asp?ItemID=cpt68314> (65) Asstd 21" Computer Monitors <http://www.dovebid.com/assets/display.asp?ItemID=cpt68316> -- "The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download <http://www.xmission.com/~legalize/book/download/index.html> Legalize Adulthood! <http://blogs.xmission.com/legalize/>

18 years, 9 months

Zen and the art of RL02 maintainance

by oldcpu2＠rogerwilco.org

Pat said: > On Thursday 13 September 2007, J Blaser wrote: >> Lastly, be cautious around the head actuator. The heads and the >> spindle (plate) are carefully aligned, and I wouldn't remove or >> adjust either of these. Unless, that is, you have the printsets and >> proper tools (which I don't). > Actually, the RL02/RL01 is an embedded servo drive, so "head alignment" > generally isn't critical, at least like it is with the RK0n drives. Yes, excellent point. I was thinking more in terms of the possibility of getting the horizontal forward/backward 'tilt' a little bit off, that is, when the heads are on the outer tracks versus when the heads are extended to the inner tracks, is the flying height the same? Also, I might add that I removed the platter brushes from three of my RL01s last year, based on commentary here on the list and other groups. I'm not sure if RL02s were ever produced with brushes, but if so, it might be worth checking. The three RL02s that I have in another PDP-11/23 PLUS never had them. - Jared

18 years, 9 months

Zen and the art of RL02 maintainance

by oldcpu2＠rogerwilco.org

Josh Dersch said: > Just picked up an RL02 for a song. It's a bit beat up looking, but it > seems pretty clean inside, so far. Glad it was for a song, and not for money! ;) > It's kind of a moot point at the moment, since I have no disk packs, > cabling, or interface boards (so I can't use the darned thing until I > complete a scavenger hunt...) but I'm wondering what I should check out > on this machine before I power it on & (eventually) start using it... Having been through four RL01 in the past 12 months, I might have something to offer. By no means am I the RL0x drive expert, but here goes... For me, the very first thing that is done (after the exterior cleaning, of course) is the reform the capacitors. These RL0x drives have two capacitors of interest: a 66,000 uF 30V, and a 22,000 uF 40V. I suppose it happens all the time, but I don't like to power up anything until I've removed the capacitors and put them through the reform(ul?)ation regime. Don't want to be too pedantic, but here are the steps I took: - remove the service cover (4 screws), then cartridge door/cover. - clean the interior as required (vacuum, Windex) - lift the DC servo PCB, make a note of the connections, disconnect the power connector - carefully lift and rotate the box above the head actuator to get access underneath - disconnect gounding wires to lugs on I/O PCB in service cover, and the inside of the rear chassis. You may find another wire to the head actuator 'box', too. - remove the four screws on the rear panel to remove the power supply (the whole rear chassis panel). Be careful as you loosen screws since the rear panel is top heavy and my tilt out when you least expect it. - Now you have full access to the PS and can disconnect and reform the caps. While the caps are reforming, here are a few other things you should consider: - take a vacuum hose to the inside of the cabinet and then wipe (windex for me) every surface. - remove the front bezel/cover to get access to the switch assembly. - your coarse filter is probably falling apart as mine were. I replaced the filter with some new-fangled Dupont furnace filter (mumble the name) which has three components: a rigid plastic stabilizing grid, a very course filter, and a fine (10 micron) filter mesh. I cut a rectangle of the fine mesh to fit and held it in place with the stabilizing grid, alos cut to fit. It works very, very well. - When the caps are done, put it all back together, and enjoy! :) I have a couple of drives the sort of quietly squeal a bit when first spun up, but I never found any information on lubrication, etc., and they quiet up after about 30 seconds, so I don't worry too much. Lastly, be cautious around the head actuator. The heads and the spindle (plate) are carefully aligned, and I wouldn't remove or adjust either of these. Unless, that is, you have the printsets and proper tools (which I don't). Good luck! - Jared

18 years, 9 months

Ancient 8086/80286 unixes?

by classiccmp＠memory-alpha.org.uk

Hi, > PE (Practical Electorncc) 'CHAMP' system, in 1977 or so. It >was built on stribboard (and IC postion layouts were given, but >you had to work out where to run the wires from the shcematic). >As was the assembly listing of the monitor ROM. A couple of years later they produced the "System 68", a 6800 based machine constructed on Eurocard sized PCBs (though using an edge connector rather than a DIN-whatever connector). IIRC circuit diagrams and PCB layouts were provided, along with a full listing of the system monitor program. You could even buy ready made PCBs (and kits of parts?) from a little company called "Newbury Data"....they actually had an office a couple of miles down the road from here at the time. Not sure whether ETI published the PCB layout for the "Triton" (I'm pretty sure they didn't, it was a fairly large, through hole plated PCB), but they sure publisged the schematics and monitor listings. Then there was the UK101.... :-) TTFN - Pete.

18 years, 9 months

EPROM Question

by ajp166＠bellatlantic.net

> >Subject: EPROM Question > From: "Zane H. Healy" <healyzh at aracnet.com> > Date: Fri, 14 Sep 2007 12:26:46 -0700 (PDT) > To: cctalk at classiccmp.org > >I've been trying to google up an answer, but have had no luck. What is the >difference between a 27256 and a 27C256 EPROM? Can a 27C256 EPROM be >substituted for a 27256? > >Zane Yes, gernerally. If your programming it limit Vpp to 12.5V otherwise the same. Allison

18 years, 9 months

EPROM programmer/readers

by healyzh＠aracnet.com

After putting it off for many, many years, I've decided to break down and do it. I'm in the market for a device to read and program EPROM's such as would be found in DEC or Commodore 64 hardware. Something that can also handle other chips (Such as PAL's) that I'd find in DEC or Commodore hardware would be nice. I'm looking for something that is either dirt cheap, or that I can build. Zane -- | Zane H. Healy | UNIX Systems Administrator | | healyzh at aracnet.com (primary) | OpenVMS Enthusiast | | MONK::HEALYZH (DECnet) | Classic Computer Collector | +----------------------------------+----------------------------+ | Empire of the Petal Throne and Traveller Role Playing, | | PDP-10 Emulation and Zane's Computer Museum. | | http://www.aracnet.com/~healyzh/ |

18 years, 9 months

Need a sanity check

by cclist＠sydex.com

I'm playing with a Computer Logics PCTD-16 Pertec tape drive interface board and my Fujitsu M2444AC drive. I can perform tape motion commands just fine, but data commands begin and do not seem to complete. I've checked that IDBY (J2 38 or W) comes ready at the end of a read or write, so my next guess is that I've got the cable wire wrong somewhow. My reference has this pin connected to pin 24 on the DC62 connector to the controller. Here's what I'm using: http://www.sydex.com/overcbl.html Have I missed something? Can anyone double-check this? Thanks, Chuck

18 years, 9 months

8-bitters and multi-whatever

by ajp166＠bellatlantic.net

> >Subject: Re: 8-bitters and multi-whatever > From: "Roy J. Tellason" <rtellason at verizon.net> > Date: Thu, 13 Sep 2007 17:33:33 -0400 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >On Wednesday 12 September 2007 07:43, Allison wrote: >> Mine started when I needed to get stuff from the various CP/M systems >> that even when they had disks were incompatable hard sector to soft >> or 8 and 5.25. I started with serial peer to peer as in pipmodem and >> similar. > >Pipmodem? That's a new one on me, though the name is pretty suggestive. PIP has an area that the user can modify as an aux device outside those in the bios (or part of the bios). Try doing a google on it. > >> Later I did a two system resource sharing that grew to allow up to a >> potential 256 systems. In '82 the whole thing peaked with a multiprocessor >> S100 crate with intercommunications via pooled memory. > >How was that handled in the hardware, particularly with regard to contention >for access? I vaguely recall running across some multiport memory chips, >but their capacity wasn't anywhere near what was currently in use that didn't >have that feature. Real simple the pooled memory was often just a block of ram in common space and each cpu had it's comminications area and a doorbell register to signal that it needs to check it's pool. The protocal was A writes to Bs com area, A hits Bs doorbell, A waits for doorbell and goes back to check As comm area. Since S100 bus arbitration allowed only one bus master and none of the areas overlapped it was very robust. It relied on bus mastering, a clear protocal and the "doobell register" to do attention requested signaling and keeps the message block from read part way while being written. By assigning buffers that do not overlap it made sure one cpu didn't corrupt anthers message. However for systems without bus master arbitation other schemes existed too. S100 IEE696 had bus master arbitration and Compupro and others used that scheme. It was by no means the only way. For example Ampro (AmproLB+) used the SCSI/sasi bus for it's communications between CPUs. Allison

18 years, 9 months

Recent acquisitions

by evan＠snarc.net

Some ultra-rare laptops I picked up recently: - Teleram T-3000 with external disk drive and manual (1982) - MicroOffice RoadRunner (1982) - Dulmont Magnum with manual (1983) What'd I spend on these? Don't ask, or my bank account might revolt against me. :) My collection of early laptops now includes, but is not limited to: 1982: - Grid Compass 1101 - Teleram T-3000 - MicroOffice RoadRunner - Epson HX-20 - Grundy NewBrain model AD 1983: - Kyocera Kyotronic KC-85 - Gavilan (eponymous.) - Dulmont Magnum - Sharp PC-5000 I'm currently borrowing a Casio FP-200 (1982) from a friend, and I own a Convergent Workslate (1982/3), but I can't decide if those are large handhelds or small laptops. It is a dilemma! Still looking to acquire a Sord IS-11 and a Xerox 1800 "Sunrise".

18 years, 9 months

Hal Hardenbergh

by james＠vartek-corp.com

Hello, I saw an old post by you where you were looking for Hal Hardenbergh. Did you ever find anything out? My name is James Shaker. I worked for him for about 5 years during the DTACK Grounded era. James -- Open WebMail Project (http://openwebmail.org)

18 years, 9 months

FYI: good Docu on tonight-PBS: Dayton Codebreakers

by ragooman＠comcast.net

FYI: good Docu on tonight- PBS: Dayton Codebreakers National Cash Register Co. conducts secret experiments to break the Enigma Code; engineer Joseph R. Desch helps end World War II. =Dan -- [ Never put off till tomorrow, What you can do the day after tomorrow ] [ Pittsburgh ---- http://www2.applegate.org/~ragooman/ ]

18 years, 9 months

ebay: Tartan Terminal System "Key to tape system"

by legalize＠xmission.com

Anyone know what this is? Looks like a weird data entry system to key in data and store it on tape for processing who knows how. Although the description could just be off... ebay item # 250164567149 -- "The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download <http://www.xmission.com/~legalize/book/download/index.html> Legalize Adulthood! <http://blogs.xmission.com/legalize/>

18 years, 9 months

8-bitters and multi-whatever

by dm561＠torfree.net

--------------Original Message: Date: Wed, 12 Sep 2007 13:31:18 -0500 From: "Ethan Dicks" <ethan.dicks at gmail.com> Subject: Re: 8-bitters and multi-whatever On 9/12/07, M H Stein <dm561 at torfree.net> wrote: > > From: "Ethan Dicks" <ethan.dicks at gmail.com> > >Since I couldn't afford an IEEE-488 disk drive, rather than just move > >files back and forth on tape, basing it upon the cable and software > >from a contemporary "Byte" magazine, I fabricated my own > >nybble-with-handshake cable between the user ports of the PET and the > >C-64, and moved stuff from one to the other over that. > > You mean you didn't just make a simple cassette "null modem" cable? > I still have the 30 footer that connected my upstairs "play" PET to the > downstairs "work" one. Lots of people (especially schools) "networked" > them that way in those distant days. Until you mentioned it now, I never would have thought of it. Back in the day, I never saw any articles in the journals about that, and nobody at any of the user-group meetings ever mentioned it or showed it off, but thinking about it now... I can see how it could work. Just a passive cable? Do you have any special notes, or was it just SAVE "FOO", 1 and LOAD "FOO", 1? -ethan =================================================== -----------Reply: Simple as that. Out to In, In to Out, and ground; preferably shielded, compatible with pretty well all models. Type LOAD "FOO" on receiving unit, run up/downstairs and type SAVE "FOO" on the other, using the alternate port on the unit that had a "real" cassette drive (2001 & VIC20 in my case, with an 8032/8050 and a massive Centronics 101 printing boat anchor at the other end), then back down/upstairs to play/work. Remember that an 8050 2FDD was around $2000+ back then IIRC, so one was enough for me. In the classrooms they'd have a "hub" (but I don't recall now whether they were passive or needed amplification). The teacher would tell everyone to type LOAD "FOO" and when they were ready everyone pressed return and the teacher would enter the SAVE. If anyone wanted to save their master- pieces, then one at a time they could send them back to the "server" and copy to disk. Since Jack T had his beginnings here in Toronto, Commodore had a pretty strong presence and when the province decided to put computers into the classrooms most of them were PETs; 2001s, then 4032s and finally C64s, although by that time Apples (and clones) were also becoming pretty commonplace. That's also one of the reasons TPUG (the Toronto PET Users Group) was so successful and in fact is still active today, not to mention Jim Butterfield's (another Torontonian) considerable support and contributions. mike

18 years, 9 months

Wang 300 Calc

by compoobah＠valleyimplants.com

The good news is that the symbols (at least for modernish interfaces) seem to be being standardized. Be nice if they back-standardized though for things like serial and parallel. Another issue with words is "which $LANGUAGE" - I remember distinctly opening up the Volvo service manual and being totally confused by "bonnet" when I was about 12. I imagine that someone in England would be even more confused by "hood" (since I think it means the drop-top on a convertible over there). Symbols are fair in that they are equally inconvienient for all. BTW "la computadora" is the standard in Latin America (where the stop signs are a red octagon with "ALTO" in them). What I would like to see is connectors designed to be easy to mate. I dislike struggling with a connector because I'm some small fraction of an inch off and eventually having to take everything off the machine and turn it around so I can see what I'm doing. The modular jacks are good for blind connections, but USB is terrible (and most D-subs are hard, too. At least 13W3 gives you a tactile method to determine whether you're right-side up).

18 years, 9 months

8-bitters and multi-whatever

by dm561＠torfree.net

------------Original Message: Date: Wed, 12 Sep 2007 19:56:02 -0400 From: "Roy J. Tellason" <rtellason at verizon.net> Subject: Re: 8-bitters and multi-whatever On Wednesday 12 September 2007 19:45, Ensor wrote: > Hi, > > > You don't even need "rs232 levels". > > MIDI is a "current loop" interface isn't it? Yup! But my point is that in prototyping some small SBC the rs232 stuff is about the only thing on there typically that needs other than logic power (+5V) unless there's some analog stuff there on the board that needs it. MIDI, in every implementation I've ever seen, uses only a 5V supply. I never did understand why current loops weren't used more... ======================== -----------Reply: On short runs you can usually get away with TTL levels on RS-232 as long as you limit the input voltage swing with a resistor and a couple of diodes or use an optocoupler. m

18 years, 9 months

8-bitters and multi-whatever

by ajp166＠bellatlantic.net

> >Subject: Re: 8-bitters and multi-whatever > From: "Ethan Dicks" <ethan.dicks at gmail.com> > Date: Wed, 12 Sep 2007 02:02:57 -0500 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >On 9/11/07, Allison <ajp166 at bellatlantic.net> wrote: >> There were a few simple schemes but excluding myself how many hobbiests >> back then had two or more systems? > >In 1982, the year you quoted for those Arcnet networks, at age 16, I >had 4 systems, a PET, a C-64, a Cosmac Elf, and a PDP-8/L (that I was >trying to repair - took until 1984, when I finally tracked down a >printset), but I'll grant you that at the time, the number of folks >that had multiple systems were probably dwarfed by the number of folks >who had only one. Of those, due to minimal I/O and/or functionality, >only the PET and the C-64 were "real" systems. I knew I couldn't be the only one but I figured not many. I was rare in I had at least 4 systems that would run CP/M making the need for interchange more deireable. By that same year I also had COSMAC ELF, SC/MP 8a-500, National Nibble basic, IMSAI IMP-48, Motorola 6800D1, NEC TK80, and a LSI-11 with TU58. I was in contact with enough people that the incidence of multiple machines was low. the more common case was a apple, TRS-80 or S100 crate with storage and one or more SBC that might have enough memory for TinyBasic. The exceptions were usually business or schools. >Since I couldn't afford an IEEE-488 disk drive, rather than just move >files back and forth on tape, basing it upon the cable and software >from a contemporary "Byte" magazine, I fabricated my own >nybble-with-handshake cable between the user ports of the PET and the >C-64, and moved stuff from one to the other over that. I might have >used serial, if I'd had an ACIA-based port for my PET (there were a >couple that sat in an expansion ROM socket), or if I'd understood more >about the nature of serial comms and crufted up my own bit-banging >routines for the PET (the C-64 had that in ROM already). I understood >parallel communications, so a nybble at a time it was. Mine started when I needed to get stuff from the various CP/M systems that even when they had disks were incompatable hard sector to soft or 8 and 5.25. I started with serial peer to peer as in pipmodem and similar. Later I did a two system resource sharing that grew to allow up to a potential 256 systems. In '82 the whole thing peaked with a multiprocessor S100 crate with intercommunications via pooled memory. > >Later, around 1983, when I picked up a VIC-20 on clearance for around >$70, I would certainly would have liked to have had a Commodore >network (based around the user port, most likely), but was unaware of >anything I could build for myself, and certainly couldn't afford any >of the "disk sharing" hardware I'd seen advertised to share PET disks >amongst multiple machines. Likely If i'd had more contact with the non-CP/M s100 world and the DEC PDP-11 world I'd have evolved things differntly. It didn't hurt that I'd had prior experience with the BOCES LYRICs PDP-8 and PDP-10 timeshare systems. The S100 world allowed me to venture into a more hardware intensive world. >It took me a few more years to learn enough about serial comms and >computer networking to be able to roll my own hardware and/or >software, but working for a serial comms networking company had a lot >to do with that. I would have loved to have been able to buy or build >something inexpensive, no matter how slow, but even a multi-serial >solution would have strained my high-school budget, as I presume it >would have strained most hobbyists' budgets, or perhaps home >networking would have gotten rolling before the days of Arcnet. >I think the first network I had any hands-on experience with was >AppleTalk/LocalTalk, when I helped my mother with a Corvus disk drive >and a room full of 512K Macs, just before she started her own business >(fortunately, by the time she did, she could afford a 20MB drive per >CPU, so the network was for printing only). By time the Mac hit I'd seeen DECnet and mixed PDP-11 and VAX system in large networks with remote printing and all the trimmings we see on the internet. >AppleTalk was a great step forward for home networking. It's a shame >that other vendors didn't follow in Apple's footsteps for many years. >I think I had an Amiga for four or five years before I attempted to >even do any serial networking (using DNet). It was well after 1990 >before I was able to stick an Amiga on an Ethernet network, and that >was with a $300 card! (there was a Zorro Arcnet card - the A2060, but >I knew I wasn't going to bother with Arcnet by that time). Appletalk was a really good, it's biggest feature is low cost both in hardware and memory footprint there were peripherals that would talk on the same net. All of the things I did and got to see and use colored my perception of what computers could do. Usually it was far greater than marketed capability. I'd believed in '83 that if a VAX or PDP-11 could network around the world a room should be easy enough. Also I'd seen what large machines could do years before and figured the only differnce doing it with a micro was either scale or speed. In the span from'82 to '89 with PCs getting faster and Ethernet and internet both catching on there was a communications explosion. What isn't discussed here is what the radio amateurs were doing with Packet networks and X.25 protocals. In some cases they were prototyping portable (toteable) networks. Allison

18 years, 9 months

DEC 874D power controller

by charlesmorris＠hughes.net

Does anyone have the schematic for an 874-D power controller? Or better yet, a good used circuit breaker? At least one of the three (ganged) breakers is internally flaky and will turn off if the handle is pushed upward all the way to "ON" (they work if the handle row is carefully lifted just far enough but obviously that is not reliable). It looks like the (original-type) Heinemann breakers are available >from Newark, and similar ones from Mouser that will probably fit, but they are *very* expensive new... thanks Charles

18 years, 9 months

Jump to page:

2026

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

2003

2002

2001

2000

1999

1998

1997

test-drb