test-drb

test-drb@ccmp.vtda.org

101090 discussions

by rcini＠msn.com

Allison: >>the mod was to bring out ras* cas* and MUX* with terminating resistors at one or both ends. These signals went through the EI cable but timing was critical at best. the later EIs derived cas* and mux* off of ras* inside rather than pipe them over. Generally speaking the mod was one where if it was mostly working it MIGHT help, sometimes it made it worse. There was another mod after that called the buffered EI cable...not a good idea either. Fixing the EI was the solution.<< One of the two units that I have has the mod and the other doesn't. The one without came with the buffered EI cable, so what you said makes sense. Thanks for the info; now I can trace the mod on the new schematics. ------------------------ Rich Cini/WUGNET - ClubWin Charter Member (6) - MCPS Windows 95/Networking

28 years, 8 months

Datamaster troubles

by rcini＠msn.com

Philip: Thanks for the error codes. I have no manuals for the Datamaster, so I'm flying blind. The code "09" is inverse-blinking, so there is a real problem. I'll try to pull the chips and re-seat them. The machine worked last summer and wasn't used since then, so I can't imagine the chip going like that. Thanks again for the help. I'll let you know what I find. My company has a UK office (Burdale-Holdings, a trade finance company). If I do need a new chip, maybe we could arrange it so that you could drop it off at our London office (if you're near it) and they could send it to me. ------------------------ Rich Cini/WUGNET - ClubWin Charter Member (6) - MCPS Windows 95/Networking Date: Tue, 15 Jul 97 09:05:06 BST From: Philip.Belben(a)powertech.co.uk To: classiccmp(a)u.washington.edu Subject: Re: Datamaster troubles Message-ID: <9706158689.AA868982856(a)compsci.powertech.co.uk> Rich Cini wrote: > Well, I'm reviving my Datamaster. Last year, it worked fine (I at least > could get into Basic). This year, I can't even get it to boot. I have no > manuals for the darned thing, so I have no idea what the numbers on the screen > during the POST mean. I have one reverse-highlighted number: "09" and I'm > assuming that this is a hardware failure code. As promised, I have hunted through my various IBM System/23 (Datamaster) manuals, and found the meanings of the POD (Power-on Diagnostics) error codes. Here is a summary: FF} 00} CPU Failure (!) 01} 02 Failure of first ROS module (Read Only Storage module, i.e. ROM chip) 03 Reserved. If this is highlighted, panic. 04 Failure in bottom 16k of storage, or of storage controller 05 CRT (presumably actually monitor) or DMA failure 06} CRT interface 07} 08 Page registers 09-} ROS failure. There follows a little diagram to tell you which chip 19 } to replace. Yes, the diagram in the manual is made of text, too. ** TOP VIEW OF PLANAR SEEN FROM THE REAR ** _______________________________________________ | ====== ====== <-- NOT FOUND ON | | | 10 | | 11 | <-- SOME EARLY | | =3=40= =3=60= <-- MACHINES | | | | ====== ====== | | | 19 | | 0D | | | =7=60= =1=60= | | *********************** | | =PATCH= ====== * PHYSICAL LOCATION * | | | 18 | | 0C | * OF ROS MODULES * | | =7=40== =1=40= * FOR EACH ERROR CODE * | | *********************** | | ====== ====== | | | 17 | | 0B | -KEY- | | =6=60= =0=60= ====== | | | XX | | | ====== ====== =Y=ZZ= | | | 16 | | 0A | XX=POD ERROR CODE | | =6=40= =0=40= Y=ROS PAGE VALUE | | ZZ=HIGH ORDER BYTE OF | | ====== ====== FIRST ADDRESS IN | | | 15 | | 09 | ROS MODULE. | | =5=60= =0=20= | | ---(CABLE)-------------- | | ====== ====== | ====== | | | | 14 | | 02 | | | 09 | CO-PLANAR | | | =5=40= =0=00= | =0=20= BOARD. | | | | (FOUND ON | | | ====== | ====== SOME EARLY | | | | 13 | | | 10 | MACHINES.) | | | =4=60= | =3=40= | | | | | | | ====== | ====== | | | | 12 | | | 11 | | | | =4=40= | =3=60= | | | ------------------------ | ----------------------------------------------- 1A-} ROS failure on feature card 26 } 27 ROS failure on 2nd printer card 28} ROS failure on feature card 29} 2A-} RAM failure. Table (which I shan't include) of how codes 30 } relate to different sizes of machine. 31 RAM page access failure 32 DMA page register failure 33 Interrupt controller failure 34 Timer interrupt failure 35 Keyboard error. If flashing, keyboard controller. If not flashing, you pressed a key at the wrong moment :-) 36 Printer failure 37 Printer not switched on 38 Diskette attachment failure 39 24 volt rail not reading 24 volts 3A-} belong to add-ons not to the system. I didn't bring the FE } relevant manual pages. General rules for interpretation: Flashing inverse video = fatal error. Non-flashing inverse video = error. Press the Error-reset key and let the machine finish booting. Then run the diagnostics dikette, I suppose. To summarise, it appears you have a dud ROM chip. I imagine the solution is to copy a ROM chip from another Datamaster. If necessary, I can arrange to copy mine, but I don't know off-hand what sort of chips they are. I would also suggest that, unless you too are in England, logistics of getting the chip to you might be hard... Philip. <><><><><><><><><><><><><><> Philip Belben <><><><><><><><><><><><><><> Das Feuer brennt, das Feuer nennt die Luft sein Schwesterelement - und frisst sie doch (samt dem Ozon)! Das ist die Liebe, lieber Sohn. Poem by Christian Morgenstern - Message by Philip.Belben(a)powertech.co.uk

28 years, 8 months

What Classic Computer are All About - A Lovers

by manney＠nwohio.com

> Hello there, I run a fileserver that has 2 ST-225 20 meg drives, and 1 NEC > 420 meg IDE drive, this system runs 24/7, and has been running for 2 months > continuous now. My question is what is the life expectancy of these drives, > it is often said that the ST-225 series are not reliable, however they > continue to run strong. also these things run so hot that you can fry an egg > on it! :) Where is the heat localized? The logic board gets hot around the bearing (bushing), but the case itself shouldn't get hot. I'd be worried. I deal with a *lot* of old systems, and I don't see any more dead ST-225's than others. I always keep an ST-225 around, 'cause I *know* it'll go on #2 in the ROM drive table if I can't locate the listing in the BIOS.

28 years, 8 months

PAM computer, Convergent?

by allisonp＠world.std.com

->On the OUTSIDE, in their scrap yard, is where most of the computer ->stuff ends up. I once found a WICAT *and* an EXORCISOR II out ->there-- both filled with water. (Sob!). Heh, I would have used that to get them cheap. Then I'd take them home wash them out throughly and disassembled and dried them well. Generally water is not that damaging. Just done power them wet. Allison

28 years, 8 months

While the cat's away...

by bw＠booster.bothell.washington.edu

;) Hi all. Due to a major computer disaster here at work I haven't been reading list mail and probably won't for a few more days. So, I'm not ignoring anyone and if anything is really important e-mail me directly (bill(a)booster.u.washington.edu). And, if anyone can tell me why 11 NT servers in a single domain would crash one at a time every 4 minutes and 20 seconds until the whole network is gone - please let me know ;). Bill

28 years, 8 months

Computer Museums

by manney＠nwohio.com

> What should be on display considering: > 1) space limitation > 2) Mainframes, minis, micros > 3) What would most attract visitors > 4) What would most attract funding :) Three things which have changed radically over the years.are - 01 Power (including speed) - 10 Cost - 11 Display capabilities (on affordable systems, that is) You might want to consider comparing the above parameters system-by-system. Software has become less klunky over the years. Try having an ancient word processor running so people can see, say, the number of steps required to open a file. Don't forget output technology...compare an old daisy wheel to a laser, a superannuated 9 pin to a modern 24 pin, get a thermal printer, and a thinkjet (really raunchy output, but FAST). I'm collecting historically significant micros (such as the C64 -- they're cheap, so everyone got one.) If you can get the dirt on why, for example, CBM shot themselves in the foot, that would be interesting. Why aren't Apples more common, for example?

28 years, 8 months

What Classic Computer are All About - A Lovers

by cerebral＠michianatoday.com

At 01:18 PM 7/15/97 +0000, you wrote: >simply too small try first: under the width of drive cage, seal the >grille holes on metal sheet and on case cover on right side, seal >that underside holes, all with a good tape. On that XT PSU, how much >airflow blowing out back, weak? Look for a replacement fan that does >better than this el cheapo fans. Try AT type case if you can, they >has bigger, powerful fan. Ok, I checked it out, and it appears that there already is a vinyl plastic glued to the front, with a 5160 sticker on it. I also put a cardboard cover in the empty bay, and this seems to work. the PSU is actually not IBM made, it is an aftermarket brand that has a strong fan in it, stronger than what I find on NEW Yackard Hells! <G> >XT case design especially in cooling department is bit goofy, blamed >by IBM for this ill. :) It continues to amaze me on just WHY whatever IBM made, as flawed as it is, the public jumped on it and supported it... look at winsucks 95..... >> there is good air flow, just they seem to run this >> hot. >More power to air flow is needed, see the tips.. >> I never ran these drives before and have no idea how hot they should >> be. as for power cycling, they get NONE. this system has been running for 2 >> months continous, without any powerdowns since they were installed, so for 2 >> months now, the thermal stability has (hopefully) stayed the same. >> thanx >Hey, no problem! >Jason D. >

28 years, 8 months

What Classic Computer are All About - A Lovers

by cerebral＠michianatoday.com

At 09:34 AM 7/15/97 -0400, you wrote: >First off why bother withg the st225s? They are slow (st251s are >faster!) and their reliability is at best ok. FYI: st225s live far I would if I had a ST-251, but I got 4 ST-225's, and 2 of them are in use, and the other 2 are spares. they are slow, but they do work nicely. I also like the sound of old hardware, the new drives you can hardly hear them run, with these, you can hear them a mile away! :) The cooling fan on this machine is as loud as the hard disks, and moves lots of warm air.. >longer if they are cooled. If the fan isn't noisy it isn't moving enough >air past them, seriously! Also if they are in the smae box as all the >other hardware they raise the other components temperature lowering their it is in an XT case, which is huge, and has one slot free for air to move.. and my room is not air condidtioned, but the house is, but the cold never travels in here! <G> >life. Heat is not your friend, this is why computer rooms are air >conditioned an usuialy under 70 degrees F. > >Allison > >

28 years, 8 months

New surplus outlet!

by kyrrin＠wizards.net

Denizens of the Bay Area, check this out! HMR Recycling (www.hmr-usa.com), when I had the opportunity to visit, reminded me greatly of one of the Surplus Warehouses of Olde. Reasonable prices, huge assortment to choose from, and 100,000 sq. feet of warehouse to peruse! Example: Nearly new-looking Tektronix 7844 dual-beam O-scope, with a pair each of 7B92A timebase and 7A26 vertical plugins, with cart: $400. Other examples: Emulex P3000 print server, $20. DEC RRD42 SCSI CD-ROM drive, $20. Exabyte EXB-8200 2.3 gig 8mm tape drive, $125. One of my finds there was a pair of DEC storage expansion cabinets at $45 each (bargained down from $50 since I bought both of them). They each contained a pair of DEC RZ57 drives (made by Micropolis, 1.0 gigs each, all SCSI). Heck of a deal! They get new stuff in literally every day. I went there twice on different days, and found some neat deals both times. 08:00-16:30, Monday-Friday only, minimum purchase $20.00, and you need to sign the visitor log and wear a visitor badge while looking around. Other than that, enjoy! -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Bruce Lane, Sysop, The Dragon's Cave BBS (Fidonet 1:343/272) (Hamateur: WD6EOS) (E-mail: kyrrin(a)wizards.net) http://www.wizards.net/technoid "Our science can only describe an object, event, or living thing in our own human terms. It cannot, in any way, define any of them..."

28 years, 8 months

What Classic Computer are All About - A Lovers

by allisonp＠world.std.com

>>>jpero... Sorry if this is long but it is important to users of classic machines. <I gently disagree with this assertion that ST251 series is good than <ST225 series. I got too many dead ST251 series compared to ST225's <due to weaker structral design, pushed design by driving steppers too <hard byond 40ms average and not as rugged as ST225's. Can't say I disagree. You however confused my assertion of better performace in terms of access times, with reliability. Its faster and more storage for less power and heat than two st225s. I never said it was more reliable. My expereince is that the st251 is less tolerrent of heat but if cooled it seems to do as well as most st225s (n=10k+). An experience with a customer in Austrailia using both 225s and 251s proved it. FYI neither like heat! <goal set by designers. If one wants faster seeking time, go voice <coil! I am dreaming wishing that ST251 drive was fitted with voice <coil instead of stepper and better motor design...sigh. true, but there are voice coil dries out there that do not hold up well too. It's a design trade made by some companies thinking the mechanics will never outlive the electronics. Much of it is process quality and handling. Most bad drives I've seen were from warm enviornments or dropped in their life. <reliably. Whole problem was that design of this ST251 spindle motor <is ill-designed to begin with in my opinion: Trying to fit all the <coils and one bearing INSIDE that spindle results in weak axle that <gets bent easily due to this design and the bearings failure rate on <this one is high too. It has a problem with gyroscopc precession, this makes it very susceptable to small shocks when running. The bearing does not like sideloads either. I agree it could have been better thought out. generally going to the smaller 3.5" was actaully an improvement in reliability for disks as it took less power to spin it and also move the heads. With less mass in the media the motors, bearings and all could be more rigid for it's size. The lower heat made bearing life better and also helped dimesional stability. < Recently I pulled this ST225 out of dumpter and fixed up the XT with < this hd and LLF'ed it. Gave whole thing to poor guy to use vax at < college. Still works. Most 225s were not fails, just retired due to small space available. FYI you get better results if the disk is LLF'd in situ and well warmed up. I must have 6 st225s of them all good and solid. I use them but, when I need speed I try to use others (quantum q540 30mb is nice!). <I tore down all kinds of drives from old and 3 years old types for <post-failure analysis which gave pretty good info for me. Same here, mostly limited to: St506, st412, st225, st251, micropolus1325 and quantum Q540, Q2190s and a few other dec disks. I have an st238 that refuses to die! <Snip! Tales of positive things about cooling... <Actually, all drives old and new benefits from cooling and boards <likes the flowing cooling air. Very true, vacuuming the vents from time to time also is a good thing. The big advantage of the newer drives is they consume less power therfore produce less damaging heat enhancing reliability. <We have no choice as many do not have AC so they ran in warm air <but if you are careful, enough fans to make hurriance out of it and <put a fan or two on monitor as well. My 17" needs two otherwise the <HOT transistor will pop again. ARRGgghhh. Tell me! I run microvaxen, Q-bus PDP-11s and s100 systems and 20 years of experince (and reliability studies) has taught me 90F is a hard ceiling and to shutdown with fans running if it gets hotter. I know this from my days at DEC in the mill when my office system (11/23) was fried by an AC failure, the area hit 98f and the 11 went down for the count. I've been pulling the plug regularly this year as we've had a lot of warm here in MA. ;-) Even without AC, every effort to remove heat is good! Even if you can't lower the ambient, keeping the guts closer to it will help greatly. My s100 crate has two 5" 120cfm fans pushing air up through the cage and it runs stone cold. The original layout had an 80cfm fan in the PS section pulling the air around and the boards ran HOT. It makes a racket but compared the the 8" drive and considering it's 20 years old... it still runs. Even my ba123 microvax, I replaced the fans to blow up as someone put them in backwards for less noise. You fight convection and lose cooling efficiencty. Since I have few spares I prefer to keep it going and tolerate a slight increase in noise. This is something to watch for on older systems where things may have been replaced but with the wrong (underrated) items. One last item. MAKE BACKUPS OF EVERYTHING. make duplicate backups and test the backups for integrity. Disks fail, and the cheapest insurance is a boot and backup package that works when you replace/repair the offending drive. Allison

28 years, 8 months

TRS-80 Model I EI question

by allisonp＠world.std.com

<I'm trying to track-down a mod that Tandy on the Expansion Interface. On o <of my early EIs (SN# 000352), there was a 6-pin DIN modification, which <someone at one time told me was to correct some erratic signal problems. the mod was to bring out ras* cas* and MUX* with terminating resistors at one or both ends. These signals went through the EI cable but timing was critical at best. the later EIs derived cas* and mux* off of ras* inside rather than pipe them over. Generally speaking the mod was one where if it was mostly working it MIGHT help, sometimes it made it worse. There was another mod after that called the buffered EI cable...not a good idea either. Fixing the EI was the solution. Allison

28 years, 8 months

What Classic Computer are All About - A Lovers

by cerebral＠michianatoday.com

At 02:45 PM 7/15/97 -0400, you wrote: > >One last item. MAKE BACKUPS OF EVERYTHING. make duplicate backups and test >the backups for integrity. Disks fail, and the cheapest insurance is a boot >and backup package that works when you replace/repair the offending drive. > > >Allison > This is why I like the 20 and 40 meg drives, I can back up key elements of the OS and configs, and restore them easily. as for 3.5 being more reliable, they are not, as I bought a Conner CFS-850A 850 meg, and it worked nicely for a year, then one day I am greeted with this error: BOOT DISK FAILURE, SYSTEM HALTED. it suffered a head crash, it would spin up normally, and when the controller tested the head actuator upon startup, there was a time when the head would seek to a location on the disk, and GRIND to a halt. the drive never worked again... I lost 700 megs of stuff, half unreplaceable (my fault, but I have no tape drive). fortunately the drive did have a 3 year warrenty, and a replacement was shipped, a 1.2 gig seagate ST-31276A. and here is another question: Is this going to last me more than a year? If Seagate made good drives in the past, will this new one live up to this, or is this drive chock full of corner cutting?

28 years, 8 months

What Classic Computer are All About - A Lovers

by manney＠nwohio.com

> Most 225s were not fails, just retired due to small space available. FYI > you get better results if the disk is LLF'd in situ and well warmed up. That's doubly true for RLL encoded ST-506/412 drives. These drives should be LLF'd from time to time anyway. Most HD controllers have a built-in LLF routine which you can access via DEBUG.

28 years, 8 months

Computer Museums

by IVIE＠cc.usu.edu

> What should be on display considering: > 1) space limitation > 2) Mainframes, minis, micros > 3) What would most attract visitors > 4) What would most attract funding :) I'm afraid number 3 and number 4 will turn you into The Boston Computer Museum. Roger Ivie ivie(a)cc.usu.edu

28 years, 8 months

Some Commie questions

by manney＠nwohio.com

C64 Porer supplies... I have a box full of C64 P/S's ...I sell them for $18 plus S/H, 60 day warranty. Got cables and manuals and lotsa software, too. I don't have any 128's. Anyone wanna get rid of one cheap? Trade a slightly used Panasonic HHP for one :> > >The next question would be, is it worth trying to repair a C64's power > >supply? I got two of them yesterday, both powersupplies are dead. It > >looks like the 5V line is shorted to ground. I did get a copy of the Old & > > if it is potted, NOPE. some are unpotted and can be fixed. > > >New style users manuals, and a copy of "Troubleshooting and Repairing your > >Commodore 64" yesterday (I love Powells Technical Books!) so I've got some > >documentation. It's been too many years since I worked as an Electrician, > >so my skill level is pretty low (wasn't very high to begin with, which is > >why I switched to computers). > > > > I have these manuals too and I must say that it leaves no tern left unstoned. >

28 years, 8 months

What Classic Computer are All About - A Lovers

by KFergason＠aol.com

In a message dated 97-07-15 13:32:57 EDT, you write: << IMHO the ST-4096 FH 80 MG was the most reliable of this era. I spent over 600.00 for this drive new and used it for more than 20 years, and ended up selling it to a business for 50.00 to replace their dead st-251. >> hmm, my experience is just the opposite with this drive. I had 6 out 7 fail in less than 6 months back in 1990. The 4096 was just hideous. Kelly

28 years, 8 months

PC-jr PSU (again!)

by ard＠p850ug1.demon.co.uk

I dug out the PC-jr Techref (in order to look up details on the joystick), and I also looked at the PSU diagrams (page B-23 in my edition). We had a thread on this about a month ago, mainly about the external transformer unit which I don't have. Now, the input connector is a 3-pin thing. The centre pin is connected to shield ground, and then via L3 and L4 on the system board to logic ground. It's thus a DC connection to the system ground. The outside 2 pins go through a filter to the AC terminals of a bridge rectifier (CR7 - CR10) and the output of this goes (via the power switch) to a 1500uF 25V capacitor (C13). The -ve side of this capacitor is also connected to system ground. Thus, IMHO it makes no sense at all for the transformer to be centre-tapped with the tap going to pin 2 on the connector. If it was, the winding would be paritially shorted out by the diodes in the bridge rectifier, which would cause a lot of damage. Also, since C13 is only rated at 25V, the maximum input rms voltage is 25/sqrt(2) volts, which is a lot less than 34V. I therefore still believe that it's a plain 17V transformer between the 2 outer pins on the connector. Incidentally, the +12V output comes from a standard linear regulator, the +5V output from a switching regulator (Z2 is the control IC, Q2 the chopper, and L1 the switching inductor). The -12V output is supplied by a secondary winding on L1, which is then rectifier and smoothed. It's always possible that IBM used several versions of the PSU card, but the schematic in my Techref seems to agree with the one in my machine. -tony

28 years, 8 months

IBM 5161??

by ard＠p850ug1.demon.co.uk

> Haven't found a IBM cassette recorder either but I did pick up an IBM > joystick (had IBM logo on it and the word "Joystick") plus it had a funky > square connector which looked like it goes to the PCjr. I've dug out the PC-jr Techref, and there's some info in it on the joystick.

28 years, 8 months

IBM 5161??

by ard＠p850ug1.demon.co.uk

> (MS-DOS machines) since about 1983 and I have yet to see one. Another > thing I've been looking for without success is an IBM Cassette recorder > for the IBM PC cassette interface. I've heard they really do exist. Now that's something I've never seen. One interesting point is that the pinout of the cassette socket on the PC (although not on the PC-jr) is the same as that on a Tandy Model 1/3/4/Coco/etc It is rumoured that IBM intended you to go down to the local Radio Shack and buy one of their recorders + cable. -tony >

28 years, 8 months

antique computer blowout (fwd)

by kjaeros＠u.washington.edu

Somebody in the Berkeley area might want to answer this call to duty.. I'd be thrilled to get the Sun 1 clone, but it'd cost several hundred dollars to ship up here. ok -r ---------- Forwarded message ---------- Date: 15 Jul 1997 07:39:46 GMT From: Paul Leondis <leondis(a)slip.net> Newsgroups: misc.forsale.computers.workstation Subject: antique computer blowout I'm looking to get rid of some stuff, let me know what you think: I've got a huge amount of old S-100 bus stuff, almost all of it with technical manuals and software on diskette, that was working the last i knew. Most is Godbout stuff, some Morrow, some Dual, etc. Lots of 8" floppy drives and diskettes. I have most of the processor boards that were released by Godbout, including 8088, 8086, Z80, 8080, 68000, and i even have some of the National Semiconductor 32000 series cpus on S-100 cards. I have all the stuff like CP/M 68K with the associated assemblers and linkers etc. I also have a complete working [?] Sun I clone: yes, that's right, the first SUN design was public domain (did you know that?? At least that's the way i understand it...) and a company called Forward Technology made clones of that design. It has a 68K cpu running in a multibus one chassis, and i have lots of peripherals for it, including 9-track tape drive and 1/4" tape drives and disk controllers for several interfaces. I've got all the relevent software, inc. V7 unix and a mess of compilers. I have the (at the time) very high res monochrome monitors that went with the system. It's a real wrench for me to let go of this stuff, if you were in this field 10 or 15 years ago you know what i paid for some of the stuff. But i'm tired of hoarding it all. So, i will take the best offer i can get for all of the stuff. My reserve bid is $0, that is i will give it away if that is the best offer. I will probably be most moved by someone that may actually get some pleasure out of the stuff and esp. someone that would want to take the whole lot. There is a free city dump day coming up in my part of town on July 19th, so i'd like to settle the stuff by then so i can dispose of whatever is left at that time. Paul Leondis leondis(a)slip.net 510-649-0993 phone Berkeley, CA

28 years, 8 months

What Classic Computer are All About - A Lovers

by thedm＠sunflower.com

IMHO the ST-4096 FH 80 MG was the most reliable of this era. I spent over 600.00 for this drive new and used it for more than 20 years, and ended up selling it to a business for 50.00 to replace their dead st-251. ---------- > From: jpero(a)mail.cgo.wave.ca > To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> > Subject: Re: What Classic Computer are All About - A Lovers > Date: Tuesday, July 15, 1997 7:59 AM > > Allison, > > I gently disagree with this assertion that ST251 series is good than > ST225 series. I got too many dead ST251 series compared to ST225's > due to weaker structral design, pushed design by driving steppers too > hard byond 40ms average and not as rugged as ST225's. > I noticed the relationship between higher stepping rate and > terrible high failure rate on many hard drives such as ST251's, > Miniscribes and early 40meg western digital drives compared to > very slow stepping rate on most drives did last long time byond its > goal set by designers. If one wants faster seeking time, go voice > coil! I am dreaming wishing that ST251 drive was fitted with voice > coil instead of stepper and better motor design...sigh. > > Those ST225, ST250 are really best consumer's drives and ST251 series > might be a mistake at cutting corners well as ST277, ST296 are same > design. > > I wished that segate designed ST251 case > more rugged and used internal spindle motor with bearings on outside > and one screw on top of cover to stablize the motor from top. Then > this ST251's would be possible to be expanded to 100 or 120 size > reliably. Whole problem was that design of this ST251 spindle motor > is ill-designed to begin with in my opinion: Trying to fit all the > coils and one bearing INSIDE that spindle results in weak axle that > gets bent easily due to this design and the bearings failure rate on > this one is high too. > > Recently I pulled this ST225 out of dumpter and fixed > up the XT with this hd and LLF'ed it. Gave whole thing to poor guy > to use vax at college. Still works. > > I tore down all kinds of drives from old and 3 years old types for > post-failure analysis which gave pretty good info for me. > > > ->X-Sender: cerebral(a)michianatoday.com > Snip! > > > First off why bother withg the st225s? They are slow (st251s are > Snip! Tales of positive things about cooling... > > If the fan isn't noisy it isn't moving enough > > air past them, seriously! > Actually, all drives old and new benefits from cooling and boards > likes the flowing cooling air. > > > Also if they are in the smae box as all the > > other hardware they raise the other components temperature lowering their > > life. Heat is not your friend, this is why computer rooms are air > > conditioned an usuialy under 70 degrees F. > We have no choice as many does not have AC so they ran in warm air > but if you are careful, enough fans to make hurriance out of it and > put a fan or two on monitor as well. My 17" needs two otherwise the > HOT transistor will pop again. ARRGgghhh. > > > Allison >

28 years, 8 months

DEC machine?

by allisonp＠world.std.com

<PC500 <RCD31 < <The PC500 seems to be a display with a 5.25 inch floppy drive and some <electronics. It is mounted on top of the RCD31 unit which is in a pizza <box style case. Is this some sort of PC clone or maybe a DecMate? It's called a Vaxmate. what it is is a PC/AT clone(sorta) with a 8mhz 286 and most had 2meg of ram, wd1003 HD controller, an st225(rd31) or st251(rd32) and a Lance eithernet interface. The floppy is RX33 (1.2mb). These are nice machines and were aimed at running as a diskless workstation to vaxen on eithenet using PCSA and later Pathworks networking. It will run dos3.3 and 5.0 that I know of. Allison

28 years, 8 months

What Classic Computer are All About - A Lovers

by thedm＠sunflower.com

Typo was intended to be 10, but it was still undauntingly reliable. ---------- > From: jpero(a)mail.cgo.wave.ca > To: Discussion re-collecting of classic computers <classiccmp(a)u.washington.edu> > Subject: Re: What Classic Computer are All About - A Lovers > Date: Tuesday, July 15, 1997 8:34 AM > > > Date: Tue, 15 Jul 1997 12:07:09 -0500 > > Reply-to: classiccmp(a)u.washington.edu > > From: "Bill Girnius" <thedm(a)sunflower.com> > > To: "Discussion re-collecting of classic computers" <classiccmp(a)u.washington.edu> > > Subject: Re: What Classic Computer are All About - A Lovers > > X-To: <classiccmp(a)u.washington.edu> > > > IMHO the ST-4096 FH 80 MG was the most reliable of this era. I spent over > > 600.00 for this drive new and used it for more than 20 years, and ended up > > selling it to a business for 50.00 to replace their dead st-251. > > Had to ask! Are you kidding? :) None 5.25" hds came out til after > '82 when lot of hds bigger than 8" was king. !!!! 20 yr old > ST4096? Impossible! More like 8 or 9 years. > > Seagate started on this design after 1986. Is this one of yours > that only have one board on bottom with only platter cover painted > black? That is last generation of this design which is finally > reliable. Earlier ones had teething problem of all kinds, no > kidding. All the way back to early first linear voice coil of ST4025 > between 1985 through '88. I pick them up all the time are almost > always dead due to bearing failures. These drives are best left > running horizontal right side up. > > Jason D.

28 years, 8 months

DEC machine?

by IVIE＠cc.usu.edu

> The PC500 seems to be a display with a 5.25 inch floppy drive and some > electronics. It is mounted on top of the RCD31 unit which is in a pizza > box style case. Is this some sort of PC clone or maybe a DecMate? No, I suspect it's a VAXmate. The VAXmate is a 286 PC clone with some special DECness (Ethernet, included software to do DECnet). Roger Ivie ivie(a)cc.usu.edu PS: Rumor has it that the VAXstation 2000 folks were really pissed that the name 'VAXmate' was already taken...

28 years, 8 months

ActionMax

by dastar＠crl.com

Picked up an ActionMax system from the thrift store today. I got it nearly complete, which is rare. Only missing the power supply (common 9V) and the VCR cable. This is a game that you hook to your VCR. It has a light gun and some sort of red either sensor or light (don't know yet). It came with a fighter combat VCR tape that you play in the VCR and I assume you use the gun to shoot at stuff on the screen. I'm sure someone else knows more about it than me. I haven't hooked it up yet. But I won't be able to do anything with it until I get the VCR cable. Anyone know how to rig one up? I also finally found a C16 but it has a broken key in the upper row :( These things apparently aren't too common in these parts as this is the first one I've ever seen. Sam ------------------------------------------------------------------------------- Computer Historian, Programmer, Musician, Philosopher, Athlete, Writer, Jackass

28 years, 8 months

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