test-drb December 2007

test-drb@ccmp.vtda.org

215 participants
420 discussions

by dm561＠torfree.net

Message: 5 Date: Mon, 24 Dec 2007 16:58:17 +0000 From: ard at p850ug1.demon.co.uk Subject: Merry Newtonsday! >Merry Christmas, Newtonsday, Yule, Winter Solstice, or whatever you celebrate >to all members of this list and their families. ---------------- And also from me, best wishes to all for a warm and happy holiday with friends and family, and a 2008 filled with successful cc restorations, one- of-a-kind finds, and/or whatever brings you pleasure and joy. mike

16 years, 7 months

Vintage Marketplace IS down (on purpose)...

by lbickley＠bickleywest.com

I was just email chatting with Sellam - here's the "scoop" on Vintage Marketplace: "Yep, a planned outage. ?We're moving everything over to a new server and new software. ?It'll take a while. ?I guess I should've done a better job of communicating this ;)" Cheers, Lyle -- Lyle Bickley Bickley Consulting West Inc. Mountain View, CA http://bickleywest.com "Black holes are where God is dividing by zero"

16 years, 7 months

CrayLink cabling prohibited on Origin 2000 deskside

by compoobah＠valleyimplants.com

On Dec 24, 2007, at 1:39 AM, Richard wrote: > Origin2000 and Onyx2 Deskside and Rackmount Installation Instructions > Document Number 108-0155-002 > 12/96 > pg. 6-36 > > "Caution: You cannot install CrayLink interconnect cabling on a > standalone deskside system because of power grounding > requirements. The power differential between two interconnected > modules should not exceed 500 millivolts; otherwise severe damage > can result to boards and other components inside the chassis. The > power distribution unit (PDU) inside the rack provides a common > ground source for the modules. In addition, the groundstraps are > installed on multirack configurations to help provide common > grounding across the racks as described in Section 6.16" > > That seems about as blunt as you can get. I'm not sure about that- you can CrayLink to Origin 200s together, the only requirement being the common ground (plug them into sockets with the same ground, run a thick ground between the chassis, or (as I have) stack them one on another if they don't have the skins). If you can do it with an Origin 200, then you can do it with a Origin 2000, since the hardware is very similar. You might need to get creative with the grounding, though, and make sure it's done well (perhaps two grounding straps of ~12AWG connected to different locations). Perhaps SGI did not design the ground point into the O2k deskside as they did in the O200, but we're a creative bunch here.

16 years, 7 months

2N2/256-BSCP

by ajp166＠bellatlantic.net

> >Subject: Re: Re : 2N2/256-BSCP > From: Dave McGuire <mcguire at neurotica.com> > Date: Mon, 24 Dec 2007 11:08:01 -0500 > To: "General Discussion: On-Topic Posts Only" <cctech at classiccmp.org> > >On Dec 24, 2007, at 3:56 AM, ard at p850ug1.demon.co.uk wrote: >>>> Given that there's a limit on the number of transistors, I don't >>>> see what >>>> advantage using SOT23s would give you. >>> >>> It'd be easier to assemble. >> >> Only if you don't spend hours looking for the transistors that flew off >> the end of your tweezers :-). > > Oh, SOT23s are easy to deal with. 01005-size components are the ones >that just disappear without a trace. > >> My point is that while SOT23s didn't exist 40 years ago, there is no >> real >> reason to prohibit them in a project like this. Limit the number of >> transistors, sure. Insist on an architecture that could be built 40 >> years >> ago, sure. But should the use of a storage 'scope to debug the thing be >> prohibited too, on the grounds that hobbyists 40 yrars ago were lucky >> to >> have _any_ 'scope? Do you prohibit writing simulators for the >> transistorised machine, on the grounds that 40 years ago hobbyists >> wouldn't have had anything to run them on? > > I'd have to agree. Actually the Accutron watch used a very small tansistor to excite the tuning fork the package was a three legged item of .095" diameter and 0.130 long with the 3 leads exiting the end. I've had 4 of them in my parts collection for over 35 years looking for a small project. Small existed back then. Keep in mind the Apollo Guidence computer is over 40 years old and that was 3input nor gates! Transistor computers were near their end 40 years ago with ICs making inroads. So comments on predominently transistor computers really have to point to prior to around 1968ish and thats within a week of 40 years ago. The interesting transistor machines are in the time frame of TX1 through PDP-8 roughly 1957 to 1967 (someon can fine tune those days). Anywho the dividing line is around 1963 and prior for germainium transistors (grown and diffused junctions types) and after then for silicon devices with superior characteristics. Allison > > -Dave > >-- >Dave McGuire >Port Charlotte, FL

16 years, 7 months

Merry Newtonsday!

by ard＠p850ug1.demon.co.uk

Merry Christmas, Newtonsday, Yule, Winter Solstice, or whatever you celebrate to all members of this list and their families. I wonder if anyone will get any classic computer related presents :-). We can always hope... I'll probably spend tomorrow doing what I've been doing for the last few months. Namely slowly restoring an HP9836 (and HP9826, they're very closely related). I am currently having problems posting to the list. Mail from my home box bounces (something about the time not being compliant with the approriate RFC). I can post from an internet cafe, but obviously not easily over the holiday period. I know I've changed nothing my end, I guess it's an 'upgrade' somewhere else... -tony

16 years, 7 months

2N2/256-BSCP

by ard＠p850ug1.demon.co.uk

> > Given that there's a limit on the number of transistors, I don't > > see what > > advantage using SOT23s would give you. > > It'd be easier to assemble. Only if you don't spend hours looking for the transistors that flew off the end of your tweezers :-). My point is that while SOT23s didn't exist 40 years ago, there is no real reason to prohibit them in a project like this. Limit the number of transistors, sure. Insist on an architecture that could be built 40 years ago, sure. But should the use of a storage 'scope to debug the thing be prohibited too, on the grounds that hobbyists 40 yrars ago were lucky to have _any_ 'scope? Do you prohibit writing simulators for the transistorised machine, on the grounds that 40 years ago hobbyists wouldn't have had anything to run them on? -tony

16 years, 7 months

Zilog S8000

by ard＠p850ug1.demon.co.uk

> Yeah, you and me both! I had two of them in 1989 or so, a Model =20 > 21 and a Model (I think) 41. I sold the former and ran the latter =20 > for quite a while. It was a really, really nice machine! ZEUS =20 > (Zilog Enhanced UNIX System) performed well and seemed nicely done =20 > overall. You're convicning me to get mine out and get it running again.... I have a model 30 (I think). It's built in 4 slices. The bottom 2 are just RS23 distribution panels, then next slice contains an SMD winchester and a QIC tape drtive, the top slice contains the cardcage. I remembr looking at the boards and seeing the Z8001 + suppoert devices, and Z80s on some of the otehr boards (not too suprising). -tony

16 years, 7 months

Unknown NEC IC's

by thrashbarg＠kaput.homeunix.org

Hi, I've desoldered some IC's off a board from an NEC workstation and there are two which I can't find any information on. Does anyone know what they are or perhaps have a datasheet? They are: D65030C022 (48 pin DIP) B6103C012 (40 pin DIP) They could be proprietary custom LSI IC's, I don't know. Also the CRT controller from the boards is a 64-pin DIP Hitachi HD63484 which will be saved for a neat project. I'm thinking of using a 6809 with UniFLEX, or even a 68000 with Minix, and perhaps making some sort of GUI for it... A long way off but I can dream :) Thanks, Alexis.

16 years, 7 months

FREE CDC CMD9448 drive

by ard＠p850ug1.demon.co.uk

> On Friday 21 December 2007 18:33, Tony Duell wrote: > > I do have the service manual for this drive. The thing I rememebr is th= > at > > you don't fiddle with the mechanics without reading it first, and even > > then tread carefully. There are all sorts of special tools you may need. > > That manual have "double sized" pages? That's what the one I have is lik= > e, I=20 > guess 11x17 or somesuch. No, it's normal A4-sih pages. Maybe fold-out schemcatis, but I don't think so. >From memory, my manaul doesn't say CDC on it, but it's clearly the same drive, I have a real CDC drive, and everything I've compared is identical. -tony

16 years, 7 months

OT sockets for Nixies

by ard＠p850ug1.demon.co.uk

> No, you still need the anode resistor. That's a > current limiting resistor. It's purpose is to prevent Rememebr that most glow discharges have a negative resistance. They will 'run away' if you don't include the limiting reisstor until the current gets so high that the tube explodes (literally!). > Remember, you don't need any fancy power IC's or DC-DC > converters - you can just rectify line voltage (an > isolation transformer is good if you do this...) and I would never recoemnd running an experimental circuit straight from the mains without isolation. Another useful trick (if your PSU already incorporates a normal mains transdormer) is to connect a small mains transformer of the same nominal voltage 'backwards' to the secodnary of the PSU transformer. That is, if you have a mains-9V trasnformer in the PSU anyway, get a small 9V mains transformer and connect the 9V winding (originally the secondary) to the secondary of the pSU transformer. You now have an isolated supply of about mains voltage, from what was originally the primary of that little transformer. -tony

16 years, 7 months

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test-drb December 2007