test-drb May 2001

test-drb@ccmp.vtda.org

273 participants
642 discussions

Magnetic Drum Storage WAS Re: Using audio cassette

by mranalog＠home.com

"Hans Franke" <Hans.Franke(a)mch20.sbs.de> said: > Well, as long as you think along a 'real' drum with flying heads > etc. you're right, but there is a simple solution - take a card > board tube and warp regular cassete tape around, and let a head > read/write this tape ... if you take an old style washing powder > drum (ca. 30 cm diameter / 1 ft) you get a lenght of about 1m > (3 ft 4") - what was the usual speed of cassetes ? 4 cm/s ? I'm > not shure (Tony ?), as a rough estimation you get a track size > of some 3 kByte and an average access time of 12s not to bad ... I have this really sick and perverted habit of picking up unusual items just in case they might be useful for future projects. All of this talk about building a drum storage reminded me of something that I added to my eclectic resource pile a few years ago, an old drum type fax machine. But, when it comes to adding mass storage to a digital computer system, IMHO I can't think of anything faster, easier, or more reliable than the old Commodore 1541. * The DOS is built-in. * Only the system side communication routines need to be written and there is commented source code to use as examples. * The drive side communication routines can also be rewritten. * Since the communication with the drive is normally handled with very robust handshaking, the speed of the computer system is totally unimportant. This also means that disk I/O can be easily interrupted. * And additional drives can be daisy-chained on the same bus. Regards, --Doug ========================================= Doug Coward @ home in Poulsbo, WA Analog Computer Online Museum and History Center http://www.best.com/~dcoward/analog =========================================

24 years

destinking the computers

by mmcfadden＠cmh.edu

Another pointer to a web page about chemicals to remove grease and nicotine for many surfaces. http://www.energy2green.com/uses4.html Seems to me that these products will clean computer stuff as well as car parts. http://www.idealchemicalproducts.com/AutoDetail-1.html I especially like the part that lets you pick the fragrance you prefer. I think Pina Colada or Bubble gum would be perfect for a Mac. :) That's the next wave in computing, different fragrances to match the color of you computer. I'm really partial to ozone when I'm around big iron. Deodorants Spray deodorants for use in auto detail shops Available in Bag-N-Box Long lasting fragrances Super concentrated Water soluble Contains no colorants USES: our deodorants are super concentrated and water soluble. Each product should be diluted with water prior to use and can be used to reduce malodors in a variety of applications including automobiles, campers, tractor cabs and sleeper areas, automobile trunks, bathrooms and shower areas, hotels and motels, nursing homes, day care centers, restaurant garbage areas and any musty damp areas. Each of our deodorants dilutes easily with water and will not harm any surface not harmed by water. Our deodorants are non staining, long lasting and economical to use. USE DIRECTIONS: mix 4 to 8 ounces of our concentrate with 1 gallon of water. Fill either a trigger spray bottle or pump up sprayer with dilute solution and spray area to be treated. Repeat if necessary. Concentrates can also be used in the evaporative air flow type room deodorizers. Simply pour concentrate into the holding container or tank and close door. All the different fragrances that we offer are listed below with product number for ordering * PEACHIE (Fruit) 4-248 * HALT (Cherry) 4-239 * LEMON 4-372 * STRAWBERRY 4-444 * ORANGE 4-241 * BABY FACE (Baby Powder) 4-312 * LIME 4-445 * VANILLA 4-242 * WATERMELON 4-255 * PINEY 4-373 * PARADISE (Floral) 4-912 * PINA COLADA (Coconut) 4-246 * RASPBERRY 4-446 * BUBBLE GUM 4-243 Mike mmcfadden(a)cmh.edu

24 years

74xx orgin

by ajp166＠bellatlantic.net

From: Hans Franke <Hans.Franke(a)mch20.sbs.de> > >Maybe I should specify my question ... I need to know >at what date these chips where at first available - >not just the era. A good single IC to use could be the >74181 ALU. Around 71. Then the H, S, LS, ALS and F parts. >> I have a 74 TTL design guide at home, so I'll check it too. > >The oldest datasheet I could find says Dec 1972 for the 74S181 Sounds close to right. The S however was later the basic 74181 was first. Infact the July 1972 issue of Ham Radio Has a supplier selling the 74181 for $4.50!! Allison

24 years

Exidy Sorcerer

by pete＠dunnington.u-net.com

On May 18, 11:30, Hans Franke wrote: > AFAIR you also have to use either 'adaptor plugs - or fit a new pwower > cable, since the Sorcerer had a fixed one. And there is nothing more > stupid in the world of power transmission than these plugs ... The power cable is fixed, but the plug on the end (that goes into the wal socket) was not a mouilded plug; it was a rewirable one, so it's very easy to remove and fit an appropriate type without mangling the cable. Not usaully a problem for me anyway, as it happens I have some Schuko sockets on my bench as well as lots of British 13A sockets. > Unless the PS is already switchable and there is a Kaltgeraetestecker > (no idea how these inlet connectors are called in english, where the > power cord is detatchable) The three-pin type I think you mean we just call an IEC inlet or IEC socket. The ones that have the notch we call "hot-condition" IEC plugs/sockets (like the ones you get on a kettle). > I always keep the original condition - for > the short time I play around with a specific unit (seldom more than a > few weeks) a stepdown transformer is a fine solution. Sensible enough, but in this case there is provision inside the Sorcerer to rewire the transformer primaries, and it's documented in the manuals. -- Pete Peter Turnbull Network Manager University of York

24 years

HP 300

by LFessen106＠aol.com

In a message dated 5/18/01 12:18:08 PM Eastern Daylight Time, cmurillo(a)manizales.autonoma.edu.co writes: > "Iggy Drougge" wrote: > -snip- > > they let me have it > > for 50 crowns. My pleasure. > > You were lucky; I'm envious. I'd like to have more of these. > Heck, I'd like to have ONE! -Linc Fessenden In The Beginning there was nothing, which exploded - Yeah right... Calculating in binary code is as easy as 01,10,11.

24 years

Slicing open the top of a 48T02 Sun Sparc chip to replace battery is that thing hollow or filled with epoxy?

by pete＠dunnington.u-net.com

On May 17, 19:34, Richard Erlacher wrote: > Has anybody tried one of the DALLAS "smart socket" products with this thingie? Unfortunately the 48T02 is a TOD clock and calendar as well as NVRAM, so there's no suitable SmartSocket to replace it. The registers have to be at particular places and use a particular protocol too. -- Pete Peter Turnbull Network Manager University of York

24 years

HP 300

by cmurillo＠manizales.autonoma.edu.co

"Iggy Drougge" wrote: -snip- > they let me have it > for 50 crowns. My pleasure. You were lucky; I'm envious. I'd like to have more of these. > Once I had bought it, though, I though that > 9000/300 was a suspiciously low number. Wasn't that some kind of 68010 based > machine? And why would such a machine have two Ethernet NICs? It probably found a second life as a router. Good for the guy who realized that the machine was still useful. > It really semed > like a waste, but on the underground ride how, I pulled out the big board with > all the ports, which seemed notably shinier and newer than the NIC above, and > found that it had a 68040. I thus deducted that it must be a 9000/380. Has > this machine been upgraded, or did HP simply not bother to identify their > machines any closer than the series (in this case 9000/300)? That's indeed the case. All hp300 systems were pretty modular, although there were some, such as the 340, that were more closed. > In any case, it came without keyboard, and I read that in order to switch it > over to serial terminal mode, one would have to perform a certain manoeuvre > via the keyboard. Bloody well thought out, HP! Is there no way to use a serial > terminal without any HIL keyboard involved? I was forced to leave my 380's monitor behind (darn hp98754a weighed about 100 pounds!) when I moved. I haven't yet gotten down to setting up the 380 in its new home, and I will have to reconfigure it to use a serial console. But I do have some HP-HIL keyboards. > The machine starts up and beeps a little. It's got not drives installed, but > there's a 50-pin "Centronics" connector marked SCSI/FS-HPIB. What is FS-HPIB? > Doesn't sound like anything I'd like to feed into my SCSI devices. The connectors in mine are marked (left to right, top to bottom) 1) BNC for LAN 2) AUI 3) parallel port (pc style) 4) HP-HIL 5) 9 pin PC style RS-232 6) SCSI/HS HP-IB (50 conductor Centronics) 7) 1/8" spkr 8) HP-IB The board is a 98574-66510 Rev C and the ROM is labeled 1818-5062 2/22/91. The cpu is a 25MHz RC 68040. Close to the SCSI header connector in the board there is an unconnected 34 pin header. Maybe that's the HS-HPIB. Indeed, HS-HPIB stands for a faster version of HPIB that was intended for mass storage only; later 300 systems such as the 370 had "human interface boards" (i.e., I/O boards) with HS-HPIB in an attached cable, plus the other usual ports and interconnects. I use the SCSI and the standard HPIB connectors in mine without problems and I am able to boot netBSD off an ST410800N on the SCSI chain or HPUX 9.1 off three 330MB HPIB drives contained in a 7963B behemoth of an enclosure; these I plug in the standard HPIB connector. I have 64MB in it. For a while, I used it as a pretty decent web server. When I get it back up that's what I am going to use it for. I've put pictures of some of the stuff above at http://jimulco.autonoma.edu.co/~carlos/hp/ No hp380 pics yet, though. Later. carlos. -- Carlos E. Murillo-Sanchez email: carlos_murillo(a)ieee.org Universidad Autonoma de Manizales, Manizales, Colombia and 428 Phillips Hall, Cornell University, Ithaca, NY 14853, USA

24 years

I *need* a Rack

by LFessen106＠aol.com

Does anyone in the list here on the east coast have a 19" rack they are looking to get rid of? I really could put on of those to goo use. -Linc Fessenden In The Beginning there was nothing, which exploded - Yeah right... Calculating in binary code is as easy as 01,10,11.

24 years

PDP-11/34 on eBay... NOT... NOT

by mbg＠world.std.com

gee, without CPU cards, it can hardly be *called* an 11/34... just a BA11 box which just so happens to have an 11/34 programmers console attached... (maybe it even has the correct backplane, but who knows) Megan Gentry Former RT-11 Developer +--------------------------------+-------------------------------------+ | Megan Gentry, EMT/B, PP-ASEL | Internet (work): gentry!zk3.dec.com | | Unix Support Engineering Group | (home): mbg!world.std.com | | Compaq Computer Corporation | addresses need '@' in place of '!' | | 110 Spitbrook Rd. ZK03-2/T43 | URL: http://world.std.com/~mbg/ | | Nashua, NH 03062 | "pdp-11 programmer - some assembler | | (603) 884 1055 | required." - mbg KB1FCA | +--------------------------------+-------------------------------------+

24 years

se/30

by philcarole＠acenet.net.au

can someone give me some info on se/30's or System 6.0.3? regards Tom, reply to:tomhotdog@hotmail.com

24 years

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test-drb May 2001