test-drb

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101090 discussions

by ajp166＠bellatlantic.net

> >Subject: Re: PDP-8 /e/f/m memory > From: Gerold Pauler <gerold.pauler at gmx.net> > Date: Mon, 14 Aug 2006 19:11:48 +0200 > To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org> > >If you are able to read german text, then the documentation of a 32KW >dynamic memory modul >from mico for the pdp8/e/f/m and /a may give some hints. >I've made a scan available under >http://pdp8.de/download/mico-mem.pdf Thanks, While I do not speak German it is still and engineering document so it's form and content are known. Makes working with foreign languages easier. It will be of some help along with the DEC docs I have. Allison > >- Gerold > >C H Dickman wrote: > >> vrs wrote: >> >>> I looked at doing one of these, but got kind of lost about how the >>> timing signals are used. I looked at the MOS RAM for the 8/A, but >>> there's all this cruft for refresh in there, some stuff about >>> suppressing access during ROM access, etc. And then it looks like >>> the memory timing signals are derived somehow from the memory refresh >>> stuff?? >>> >>> Is there a nice place where the Omnibus memory interface control >>> signals are explained somewhere? >>> >> >> I did a semiconductor memory design for the OMNIBUS several years ago. >> It was for an -8/e and 32kW using two SRAMs. I never got to >> documenting it outside of my notebook, but if there is enough >> interest, I could do some schematics. It is battery backed, so its >> pretty much equivalent to the core I was replacing. >> >> The Small Computer Handbook, the maintenance manuals and timing >> diagrams from the processor print sets had enough information for me. >> >> -chuck >

19 years, 10 months

EX2000 Floppy Drive Tester

by jdaviscctalk＠soupwizard.com

Hi, I ran across an interesting gadget at a university surplus sale, maybe someone can tell me how useful it is. It's an EX 2000 Disk Drive Tester. It came with a couple manuals and some 5.25" alignment floppies. The manual says it's "used to align and repair floppy disk drives with industry standard SA400 and SA800 interfaces", and says the connections on the end are for 5.25" and 8" drives. Here's a photo: http://www.soupwizard.com/temp/ex2000.jpg I'm extremely unlikely to be doing any floppy repairs myself, so would this be useful to anyone else? Jeff

19 years, 10 months

Early 1980s "Computing" magazine?

by evan＠snarc.net

Does anyone have copies of "Computing" magazine from 1981? I think this was a British publication but I'm not certain. Specifically I'm looking for an article in the April 9 titled "NewBrain order freeze as project is reviewed" or something similar. That information is from http://tinyurl.com/z9e5l. - Evan

19 years, 10 months

Computers and Heat Density (OT)

by compoobah＠valleyimplants.com

e.steibler wrote >I know, it is an M$ nightmare... Not really- MS will just send its sales force out after the higher-level managers who don't know much about computers, same as now, tell them how Linux is "unsupported" and other UNIXes are "proprietary" (and Windows isn't???), perhaps touch on the SCO threat, imply that UNIX admins are hard to come by and expensive... get them to commit to Windows as a platform and buy a 16p Itanium server with Windows Enterprise, thin clients, and a nice big $150 terminal license for each client. No nightmare there, the MS will probably also sell an Office license per client too.

19 years, 10 months

Computers and heat density

by ken＠seefried.com

From: "Chuck Guzis" <cclist at sydex.com> > Did the CDC 6600 ever have a C implementation? Dunno about the 6600, but it's decendent the CDC Cyber 180 did. I never even looked at it (the Algol 60 compiler was more interesting...I have the manual for that someplace), but I understand it was painful. Ken

19 years, 10 months

PDP-8 /e/f/m memory

by ajp166＠bellatlantic.net

> >Subject: Re: PDP-8 /e/f/m memory > From: "vrs" <vrs at msn.com> > Date: Mon, 14 Aug 2006 00:04:38 -0700 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > >> Even schematics would help. In the end I may do my own as >> a pair of 61256s will certainly fit the bill and barely fill >> a corner of a board. > >I looked at doing one of these, but got kind of lost about how >the timing signals are used. I looked at the MOS RAM for the 8/A, >but there's all this cruft for refresh in there, some stuff about >suppressing access during ROM access, etc. And then it looks like >the memory timing signals are derived somehow from the memory >refresh stuff?? > >Is there a nice place where the Omnibus memory interface control >signals are explained somewhere? Small Computer Handbook 1973 is a good staring point. A complete prinset also has details like timing. Allison

19 years, 10 months

OT: Help needed in forwarding an item

by quapla＠xs4all.nl

Hi all, I need someone in the U.S. to forward some items to me. The seller of the items does not ship anything outside the US. The item are 6 large capacitors. Doesn't have to be done for free, and postage gets paid as well of course. Please reply off-list. Thanks, Ed

19 years, 10 months

Hi, I'm new...

by aliensrcooluk＠yahoo.co.uk

--- Tony Duell <ard at p850ug1.demon.co.uk> wrote: >> snip << > > > I know how the CPU works and runs everything > > , in theory, but I can't program in machine > > language yet. > > As for how the CPU and everything else works > > physically, I don't really know anything, but > > There are, unfortunaely, very few books that > actually explain how the CPU > works. Most introductory hardware books explain > things like the AND and > OR gats and flip-flops (don't worry if these terms > mean nothing to you, > they're just the basic building blocks of computer > circuits), and then > tell you the CPU exists. It's almost as if the CPU > runs on some kind of > magic. > Hehe... abracadrabra. > I can assure you that it doesn't, and that many > older, simpler CPUs are > understandable at the gate level (or even the > transistor level). > > I know how _I_ learnt this stuff. I had already > understood how to use > gates, flip-flops, etc. I mamaged to get the servi ce > manuals for an old > minicomputer, and I sat down for a couple of > _months_ until I understood > it all. Of course back then there was no classiccm p > list, I didn't have > anyone to ask. I was very much on my own. > Perhaps there are service manuals for the Amiga?? I know I wanted to get my hands on the Amiga RKRM's (Rom Kernel Reference Manuals), but they will be hard to find in paper form. > > [Mains voltages etc] > > > > voltage is lethal. It's also likely to appear on > > > metal heatsinks, etc, in > > > such supplies. Don't work on one of those unle ss > y > > ou > > > really know what you > > > are doing. > > > > > > > Ok... no heat sinks in my A600 :) > > It's only heatsinks in high voltage circuits (like > the mains side of > SMPSUs, or the horizontal scan section of monitors > and TVs) that might be > at a dangerous voltage. Heatsinks, say, on top of a > CPU chip, or a > regulator IC on a motherboard, are very likely to > be at ground > potential. But if in doubt, ask. > Ok. > > > > > > > Monitors are often claimed to contain lethal > > > voltages. Well, there's > > > mains (and most colour monitors use an SMPSU> > circ > > uit, so the hazard I've > > > just mentioned is there). But the even higher > > > voltages to the CRT are > > > generally only able to supply low currents, an d > ar > > e > > > unlikely to be fatal. > > > Don't take risks, though, 25000V is darn > unpleasan > > t. > > > > > > > No problems there either, as I don't use a > > monitor. I plug my A600 into my TV via the > > RF cable. The picture quality is good enough > > for me. > > Well, a TV is essentially a monitor with an extra > bit -- the radio > receiver circuit -- added. It also contians high > voltages to operate the > CRT. And most, if not all, modern TVs use a SMPSU > circuit. > > Doesn't your TV have a SCART socket? Can't you > connect the RGB outputs of > the A600 there? > > -tony > No RGB cable for the Amiga and the SCART socket is already used: I have a 3 way SCART box which is plugged into the TV's SCART, with SCART's from the VCR, DVD player and my Dreamcast plugged into that. I have used the old Sega Megadrive (aka Genesis) RF switch box (the one that lets you switch between "Game" and "Aerial") and plugged that into the aerial socket on the TV. Into the switch box I have the aerial (for terrestrial TV) and my Amiga RF cable. The A/V sockets at the front are used by my Nintendo 64 (which is sat ontop of the TV), or Gamecube (sat next to Dreamcast under TV, but ontop of VCR and DVD player) depending on which Nintendo console I want to play. It's a nice setup.... but loads of cables :( Besides, it's not like I'm gonna try and do Hi-Def stuff on the Amiga! (NB: I know that ain't possible, unless you count the 2 colour super-hires screen mode - and before anyone asks I know nothing about Hi-Def screens and/ or widescreen TV's, but thats ok coz I don't want them). Regards, Andrew B aliensrcooluk at yahoo.co.uk

19 years, 10 months

Handwire vs PCBs

by compoobah＠valleyimplants.com

When you're using a PCB, though, you have a large flat plane for the solder to deal with. If you're doing point-to-point and you don't make a good mechanical connection, then it is likely that you won't have much solder to stick it together with. A good mechanical connection also gives you more surface area for the solder joint.

19 years, 10 months

Miniature CPU repro (was Re: group buy for homebrew CPUs?)

by ethan.dicks＠gmail.com

On 8/14/06, Bill Sudbrink <wh.sudbrink at verizon.net> wrote: > I have been toying with the idea of doing a one inch to one foot > (doll house scale) fully functional IMSAI. Clearly, it would be > implemented on some sort of PAL or PIC... the idea would be for > the front panel and a serial port (maybe a video out too (cromemco > Dazzler?)) to be fully functional with a "floppy" drive implemented > on one of the little flash memory packs. Hmm... at 1/12th scale... I would think the front panel would be the tricky part. The interior shouldn't be so bad. One could use a camcorder eyepiece display for the CRT, if you did a Dazzler. Be a bit tough to read text, though. I take it you wouldn't be considering working switches on the front panel, only blinkenlights, right? Sounds interesting. Would make an interesting VCF display. -ethan

19 years, 10 months

SMT techniques (was Re: group buy for homebrew CPUs?)

by ajp166＠bellatlantic.net

> >Subject: Re: SMT techniques (was Re: group buy for homebrew CPUs?) > From: Brad Parker <brad at heeltoe.com> > Date: Sat, 12 Aug 2006 06:44:50 -0400 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > > >"Ethan Dicks" wrote: >> >>I _have_ thought about that for replacement -8/L and -8/i boards - > >Just curious, are there any machine readable schematics or netlists >for the 8/I? > >(from my primative understanding an 8/i was made from a few different >flip chips and a *lot* of backplane wirewrap - just wondering if that's >machine readable anywhere) That decribes a fair amount of the 8i and 8l. One it's I've been looking for is if anyone has done a semiconductor memory for the 8e/f/m omnibus machines. There was a hex wide one for the 8A. I figure it would be handy for those that don't have enough core or fully functional core. Allison

19 years, 10 months

new acquisitions

by jwest＠classiccmp.org

Just received 3 packages in the mail today from 3 different folks... 1) What I believe is a complete PDP-11/40 cpu cardset (M7231 through M7238 {yup, EIS}). Is this a complete set? Too bad that won't magically make my 11/45 start working. 2) DEC Microprocessors Handbook (poor condition, but I didn't have one, so nice!). 3) An MDB systems "MDB-DR11C". What exactly is this? Is it the same as a DEC DR11C? What was it commonly used for? Also in the box was an ACT "10015000" which I'm guessing may be a 4-slu card? Yay! Jay

19 years, 10 months

Asynch designs

by compoobah＠valleyimplants.com

> Supposedly, non-clocked logic can also offer greater security because >there's no clock signal for remote sensors to key on when trying to >sense what the CPU is doing. This seemed a little odd to me. Do >espionage types really try to sense what a processor is doing >remotely, based on the EM emissions from the chip? Don't know about processors, but Tempest had a proof of concept for intercepting I/O from kbd/video. (Anyone else remember Tempest? for a while they were selling big "tinfoil hat" type shields for monitors and then, suddenly, it went away.) Was that NSA that came up with the POC? P.S. - for the U.S. types - never would have thought it 15 years ago, but NSA now has official mousepads you can buy.

19 years, 10 months

More mags

by brain＠jbrain.com

Now that I got Scott's treasure on it's way, here's a few more options. Scott is not eligible :-) Issue 37-136 of Circuit Cellar, plus a few volume 1 (1.6 and 1.8) and volume 2 issues. I regret ditching this, but I never read them, and I can get them via CD if I do want them later. Mixed (16 or so) issues of Popular Electronics from '93 to 99. dozen or so issues of Modern Electronics/ComputerCraft/Microcomputer Journal from '90 to '97. Mostly 95-97 (Microcomputer Journal) No hoarding, first come, first serve, I'm asking only for shipping costs >from Iowa (52402). Anything not claimed hits the recycle bin after a week. Jim

19 years, 10 months

Handwire vs PCBs (was Re: group buy for homebrew CPUs?)

by ethan.dicks＠gmail.com

On 8/14/06, Chuck Guzis <cclist at sydex.com> wrote: > I think the big problem was a shift in thought. Anyone who learned to > solder back in the handwired days remembers being told over and over again > that "Solder does not make a mechanical connection". Or in other words, > good wiring practice demanded that a wire be mechanically attached to its > terminal before solder was applied. Along come PCBs and what's holding > everything together? Solder. My dad (who was a Ham in the 1950s) told me over and over that solder is not a load-bearing material. Of course, given the weight of 1950s components, if you _don't_ make a good mechanical connection first, a solder-only joint is likely to fail eventually. I remember how hard it was to tear apart stuff from those days... I needed a solder gun and a quick hand with the needle-nosed pliers to start to unwind the leads from the solder tabs before the mass of the pliers cooled the joints. OTOH, a technique I've picked up from a co-worker here for nice faraday-cage-type enclosures (for RF-emitting/using projects) is to solder a box from chunks of copper-clad board. It's easy to work with and for stuff that small enough to fit in your hand, *very* strong. -ethan

19 years, 10 months

group buy for homebrew CPUs?

by trag＠io.com

>Date: Sun, 13 Aug 2006 10:09:54 -0400 >From: Dave McGuire <mcguire at neurotica.com> >On Aug 12, 2006, at 4:37 PM, Jeff Walther wrote: >> BGA components have a specification for the clearance between the chip >> package and the circuit board after soldering. I don't think you >> could meet that just by putting the thing in the oven. > > Very true...but I've looked far & wide for a reason for that >specification to exist, and have found none. The only thing I can >think of is the possible flattening out of the balls causing them to >short against adjacent ones...but is that really possible? Not sure. I assumed (certainly don't *know*) that the specification is there because if the chip finishes too high above the PCB, then you didn't melt the balls enough and you may have cold joints, etc. and if the chips finishes too low/close to the PCB, then you've squished the balls too much and they may be in danger of shorting. At the least, it seems to me that if you meet the clearance specification, you're more likely to succeed at BGA soldering without expensive equipment to inspect the hidden solder balls. I could be wildly wrong though. I never carried through with my experimental ideas. Another thought is that if you use the feeler guage idea that I proposed, then you can heat the chip and board more thoroughly without the chip sinking any closer to the board. That should help to ensure good solder joints on the interior balls without allowing the chip to squish to close to the board. I think I was looking into it when the PPC750FX and later the PPC750GX came out and I really wanted to get them onto a ZIF module of the type that plugs into the Beige G3 model Macintosh. But Powerlogix came out with a couple of nice cards, so buying commercial became cheaper and more practicle than trying to do it myself. (Thank goodness!) Jeff Walther

19 years, 10 months

Handwire vs PCBs (was Re: group buy for homebrew CPUs?)

by ajp166＠bellatlantic.net

> >Subject: Handwire vs PCBs (was Re: group buy for homebrew CPUs?) > From: "Ethan Dicks" <ethan.dicks at gmail.com> > Date: Mon, 14 Aug 2006 14:13:09 +1200 > To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> > > >OTOH, a technique I've picked up from a co-worker here for nice >faraday-cage-type enclosures (for RF-emitting/using projects) is to >solder a box from chunks of copper-clad board. It's easy to work with >and for stuff that small enough to fit in your hand, *very* strong. > >-ethan I use that thechnique all the time to build RF assemblies where stray signals need to be bottled up to prevent unwanted signals in the wrong places. the advantage is not only is it a good shield but using scraps (cheap material) you can build custom enclosures for subassemblies. To keep this on topic at least somewhat. Years ago I built a PLL subsystem for a radio with a micro to do the tuning and display chores. The RFI from all that (8748 with led drivers and input controls) was unbearable. Boxed it all up as previously described using copper screen across the display opening and it was reduced to dead silent. Of course the few wires (power, slow parallel digital signal for tuning and switches) entering and leaving had to be properly filtered as well. Allison

19 years, 10 months

group buy for homebrew CPUs?

by trag＠io.com

>Date: Fri, 11 Aug 2006 15:58:16 -0600 >From: "e.stiebler" <emu at e-bbes.com> >Chuck Guzis wrote: >> On 8/11/2006 at 4:37 PM shoppa_classiccmp at trailing-edge.com wrote: > >> I suspect that the legacy DIP stuff will get harder to buy new through >> "normal" channels, given RoHS. In the long run, I suppose we'd all better >> get used to working with surface mount. :( > >Yup, get ready to solder .2 mm balls on 800 balls BGA. >Get your toaster-oven ready ;-) BGA components have a specification for the clearance between the chip package and the circuit board after soldering. I don't think you could meet that just by putting the thing in the oven. However, it might be interesting to get some feeler guages the same thickness as the clearance that that specification calls for, place the feeler guages around the edges of the chip between the chip and the board and then heat the chip and board until the chip presses down on the feeler guages. That *should* give the proper clearance and therefore the appropriate solder ball "squish". I don't know how one reballs BGA components though. Anyone care to explain? Jeff Walther

19 years, 10 months

semiconductor mfr. logos page

by trag＠io.com

>Date: Sat, 12 Aug 2006 20:53:39 -0400 >From: "Roy J. Tellason" <rtellason at verizon.net> >Subject: semiconductor mfr. logos page >To: "General Discussion: On-Topic and Off-Topic Posts" > <cctalk at classiccmp.org> >Message-ID: <200608122053.39577.rtellason at verizon.net> >Content-Type: text/plain; charset=us-ascii > >A while back I'd sort of thrown something together with a bunch of logos on a >web pages, and since Jay expressed some interest in that some time back I >uploaded it, but since I wasn't happy about a number of aspects of it back >then I didn't link to it and didn't publicize it. ICMaster.com had a few pages of logos and manufacturers' names in alphabetical order, back when. They seem to have revamped their web site and maybe been taken over by someone else. I can't find their logo pages any more. Anyone else have any luck? Jeff Walther

19 years, 10 months

KVM's

by aliensrcooluk＠yahoo.co.uk

--- jim stephens <jwstephens at msm.umr.edu> wrote: > Don wrote: > > > > > > > It doesn't take long to realize that this is a > non-solution: > > - keyboards are PS2, Sun, USB, ADB, etc. > What does ADB stand for? The reason I ask is that my initials are ADB (my middle name is David), and every time I see it in a message it throws me for a split second. Regards, Andrew B aliensrcooluk at yahoo.co.uk

19 years, 10 months

Pictures of old S-100 cards?

by jcwren＠jcwren.com

I've been putting some S-100 cards on eBay, and I started wondering if anyone was maintaining a database of pictures of old cards. If not, and someone chooses to start one up, anyone is welcome to my pictures. http://tinymicros.com/ebay is where they're located, starting somewhere on page 20 or 21. They're not great photographs, but they're more than adequate to help identify boards and such. --jc

19 years, 10 months

HP 1000 double integer instructions info

by jdbryan＠acm.org

I'm working on adding double integer (32-bit) instructions to the HP 1000 simulator under SIMH. The 1000 F-Series computer came standard with these instructions, and I have documentation on the opcodes used. The E-Series did not have them, but there was a "specials group" product -- HP number 93585A -- that added firmware support for these instructions. However, the opcodes were different from the F-Series opcodes to avoid conflict with other E-Series microcode options. Does anyone have information on the opcodes used in the 93585A product? I have found a reference to a manual, HP number 93585-90007, "93585A Double Integer Firmware Installation and Operating Manual," but I cannot locate a copy. -- Dave

19 years, 10 months

KVMs

by compoobah＠valleyimplants.com

Don intones: > >Is it possible to add a second Crestor/Elite FB? (Sorry, I haven't >poked around inside this box, yet) Nope, UltraSPARC IIi doesn't support enough spare UPA ports. You can get a PCI PGX card if you so desire. Some of the bigger systems that use the full UltraSPARC II or UltraSPARC III with the external UPA/Crossbar controller offered more graphics ports. I think the 60 and 80 did, as well as the deskside beasts (and I suppose you could wedge a few screens into an Ultra Enterprise 10k if you wanted...) Even with the full UltraSPARC implementation, many smaller machines (e.g. Ultra 2) only had one UPA expansion slot for size reasons (and, I suppose, to protect the profit margins of the high-end systems).

19 years, 10 months

SMT hobby projects (was Re: group buy for homebrew CPUs?)

by aliensrcooluk＠yahoo.co.uk

--- Dave McGuire <mcguire at neurotica.com> wrote: >> snip << > > I bought a pneumatic solder paste pump for $75, > and two different > very high-end hot air pencils for $50 and $120, al l > on eBay over the > past several years. The stuff is out there. $50 > for an air pencil > which will likely run for decades is not a bad > investment in my opinion. > > -Dave > > -- > Dave McGuire > Cape Coral, FL > As a newish member and someone not experienced in circuit board repairs/modification, could someone please explain what they (the pneumatic solder paste pump and the hot-air pencil) do, please? Regards, Andrew B aliensrcooluk at yahoo.co.uk

19 years, 10 months

Questions on convergence...

by newyork.techie＠gmail.com

well ok then, if that is the case, does anyone know of anyone who may have the manual for the specific model I had mentioned? Hitachi CM2111MJ 512? John Boffemmyer IV

19 years, 10 months

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