test-drb April 2005

test-drb@ccmp.vtda.org

269 participants
730 discussions

by James＠jdfogg.com

> I was just contacted by a guy asking if I have any info on > this computer called "Jupiter J12": > > http://www.geocities.com/australianvintcomp/Jupiter/Jupiter.html > > I don't - anyone got any information I can pass on ? >From the pics and the joysticks on the keyboard I'd guess this was for some sort of video editing.

20 years, 1 month

Jupiter J12

by dave04a＠dunfield.com

Hi Guys, I was just contacted by a guy asking if I have any info on this computer called "Jupiter J12": http://www.geocities.com/australianvintcomp/Jupiter/Jupiter.html I don't - anyone got any information I can pass on ? Regards, Dave -- dave04a (at) Dave Dunfield dunfield (dot) Firmware development services & tools: www.dunfield.com com Collector of vintage computing equipment: http://www.parse.com/~ddunfield/museum/index.html

20 years, 1 month

Power Supply for Laser XT Computer

by alhartman＠yahoo.com

Well... The power Adapter for my Apple IIC isn't compatible with the Laser 128. It needs +/- 5V and +/- 12V. Does anyone have such a power supply, or know where I could get one? Thanks! Al __________________________________ Do you Yahoo!? Plan great trips with Yahoo! Travel: Now over 17,000 guides! http://travel.yahoo.com/p-travelguide

20 years, 1 month

SCSI CD drive capable of reading CD-R

by bpettit＠ix.netcom.com

Oh what a long string and so much to comment on. Not certain who started this so don't know if he wanted only a read function SCSI drive or wants a CD-R burner with SCSI interface. If it is a burner, I might have a couple left. The Yanahas are all dead, but I think the Philips are still working. Billy

20 years, 1 month

Magnesium Fires, was Re: HP-2116A chassis (or repairing cast aluminum)

by marvin＠rain.org

Many years ago, I did some machine work on magnesium and kept the chips. At some point, I wanted to see how it would burn and put a small pile of chips on the sidewalk and lit it with a match. Burned *very* nicely all the way up to the time the concrete exploded from all the heat being generated (and probably moisture from rain the day before.) It left a scar above one eye and put a hole in my dads brand new convertable top. People still wonder how I managed to live this long :). > > Alex wrote: > >> No need to worry - trying to get a magnesium case to burn is _hard_ > > > > Actually, it's very easy. You just grind it up into powder first. > > Time-consuming, but not particularly difficult. > > > Once a small part is ignited, it will burn quite well in solid chunks if > it gets enough oxygen. > A bit of iron oxide can make the situation very interesting. > > Drilling or grinding magnesium without proper precautions is risky. > Welding is done with inert gas, so that is usually quite safe. > > -- > Bj??rn >

20 years, 1 month

PDP11/55 sells on Ebay for 5K$ - was it really the fastest 11?

by ajp166＠bellatlantic.net

>Subject: Re: PDP11/55 sells on Ebay for 5K$ - was it really the fastest 11? > From: "Heinz Wolter" <h.wolter at sympatico.ca> > Date: Mon, 18 Apr 2005 01:00:13 -0400 > To: "Lyle Bickley" <lbickley at bickleywest.com>, <cctalk at classiccmp.org> > >snipe >Lyle wrote: >> > I expected an 11/70 to be instruction for instruction faster - but >> > add all the cache and complexity - maybe the 55 with bipolar ~was~ >faster? >> > How about compared to a 11/70 with a PEP70 instead of factory memory and >> > cache? >> > Isn't a 55 just a 45 with bipolar instead of core? or was that a 50? >> >> Read "Computer Engineering" (Gorden Bell, J. Craig Mudge, John E. >McNamara), >> Copyright 1978 by Digital Equipment Corporation >> Page 408 >> -------- >> Model Basic Instructions Floating Point >> Inst. per second* Inst. per second >> ------------------------------------------- >> 11/70 36 671 >> 11/55 41 725 >> * Relative to 11/03 >> No brainer - the 11/55 wins hands down. > >sigh - I haven't memorized the DEC sacred texts yet;) no hardcopy, only >pdf... >So the 55 is roughly 14% faster than 70 - probably due to main memory >timing. >This might not be the case with the PEP70, though it's not stock. >Interesting >that the FP is only 8% faster - given that they are likely similarly >microded and >memory would not be such an issue working out of the FP registers. Clock >speed? >Then again... if one put 2 MW of 300ns ram on a 70.. well the 55 was only >18 bit address ;) >Anybody know the microclock frequency of both models? Variable timing/phase? >This variable microclock trick was later used in Vax/750 hot wiring kits.. >On a similar vein, wasn't the 11/34c clock slowed to allow for cache timing, >making >it slower than a 34A? (for uncached accesses) Is is this a possible reason >for the 70's >poor performance? Running code withing the cache should have beaten the 55! >h Sorry, while for those metric the 55 was a tad faster, for IO the 11/70 was massively faster. At that time to do large arrays of data you needed lots of fast IO to disks as you could only works with part of an array at any time due too addressing limitations of the PDP11. When you measure systems, measure the system not just the cpu. Allison

20 years, 1 month

Questions - Universe/68, HP-9134A,VT420 composite video

by david_comley＠yahoo.com

I have a couple of questions - and requests for assistance - for some of the items I picked up this weekend from TCF. My other post to the list details what there are. Here goes: - HP 9134A: The unit is appears on the HPIB bus but doesn't identify itself correctly. From the HP64000 side I get a 'NO DISC' error when I try to format it. I am trying to determine whether the light on the front of the ST506 inside should be on or not once the drive comes up to speed or whether it only comes on when that HBIB address is being accessed. Any hints ? - Universe/68: Operating system for the Charles River Data Systems Universe/68 anyone ? I understand these machines used to run UNOS. It would be fun to try to boot this thing. Also - any background information on the machine itself would be of interest. - I'd like to use a surplus VT420 as the display for the DEC 350 Pro I picked up. This will entail identifing a point on the VT420 schematic where I can inject the composite video signal from the 350. So I need the VT420 schematic. Does anyone on the list have one ? - manual or operating notes for the Zia Tech ZT 488 ? I can probably figure this one out but documentation is always welcome. Thanks as always for the list's help. Regards, Dave __________________________________ Do you Yahoo!? Plan great trips with Yahoo! Travel: Now over 17,000 guides! http://travel.yahoo.com/p-travelguide

20 years, 1 month

WarGames tape

by jrkeys＠concentric.net

While working the flea market this weekend I picked a VHS copy WarGames and watched it Sunday afternoon. It was strange to watch the many shots of mainframes that were in the movie but I notice none seem to be in air condition rooms? One looks like a 360 or 370 system and another shot may be a minicomputer with all the disk/tape drives and printers. That IMSAI still looks great in his room, wasn't that computer sold on eBay? The VHS tape was only 50 cent at the market.

20 years, 1 month

Looking for Multibus cards and SMD drives ...

by silvercreekvalley＠yahoo.com

Looking for any Sun era multibus cards (anything) and a working SMD HD drive (anything that has some chance of working with a Xylogics 450/451 SMD board). Both for an old Sun rescue. Cheers Ian. __________________________________ Do you Yahoo!? Yahoo! Small Business - Try our new resources site! http://smallbusiness.yahoo.com/resources/

20 years, 1 month

HP 2100/21MX boards available (and needed)

by jwest＠classiccmp.org

I have some boards available, and some others I desperately need. Trades anyone??? Available (and thoroughly tested to work - multiples of each available): + TRUE IN/OUT Time Base Generator (TBG) 13037 Disc Interface (the PCA, not the rackmount box) Jumper BACI High Performance Memory for E/F (various sizes) High Performance Memory Controller Standard Performance Memory (M, various sizes) 1K WCS for M?/E/F (only one available) WCS for 2100 (only one available - untested, and may already be spoken for) Need: 3 GRD TRUE IN/OUT 1 Firmware Accessory Board (FAB) 1 Dual Channel Port Controller (DCPC) 1 8-bit duplex register Notes: 1) I'd prefer the WCS & 1K WCS to go to someone who actually plans to do some microcoding, not just sit on a shelf 2) I'd prefer to trade some of the available boards for the needed boards, but may be swayed with other gear :) Regards, Jay West

20 years, 1 month

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test-drb April 2005