test-drb August 2006

test-drb@ccmp.vtda.org

216 participants
517 discussions

by h.j.stegeman＠hccnet.nl

Hi Jim, > Greetings. >I purchased a couple weeks ago a metal box full of >unit record docs, forms and cards ($20). Including >Ramac 305 guide and manuals for various collating, >punching, as well as some training manuals. I'd be >happy to have it go to a good home. I've got a >spreadsheet with more details I can send on request. >The box full is very heavy so I would a pickup in the >San Francisco Bay area. >. >Thanks, Jim Bitsavers.org would very good home for these IBM manuals. Regards Henk IBM collector

19 years

async designs

by technobug＠comcast.net

On Fri, 11 Aug 2006 12:58:56 -0700, Brent Hilpert <hilpert at cs.ubc.ca> wrote: >> Chuck Guzis wrote: >>> At one time async logic was a hot topic. >> >> The IAS machine (von Neumann/late 1940s) is listed in various >> places (under >> 'clock rate') as being 'async'. (And - annoyingly - those listings >> then don't >> provide an effective instruction rate for the sake of comparison). >> >> I've been curious as to more precisely how the timing was >> accomplished in that >> (those) machines. Offhand, I suspect you still end up with delay >> elements in >> the design at various points to ensure some group (worst case) of >> signals/paths >> are all ready/stable at some point and you end with a more-or-less >> 'effective >> clock rate' anyways and don't gain much. >> >> Such all started with ENIAC didn't it?, which - based on what I've >> been able >> to find/read - could be described as an async design. >> Was async still being discussed in the 60's? > Serious theoretical work was done for relay logic prior to ENIAC and it definitely isn't dead right now. There is a substantial amount of work being done in the area with the UK being a hotspot of activity. Early this year ARM and a Philips subsidiary released an ARM core that was entirely async. For those interested, this is an excellent resource: <http://www.cs.manchester.ac.uk/apt/async/> CRC

19 years

async designs

by trag＠io.com

>Date: Fri, 11 Aug 2006 12:58:56 -0700 >From: Brent Hilpert <hilpert at cs.ubc.ca> >Chuck Guzis wrote: >> At one time async logic was a hot topic. > >The IAS machine (von Neumann/late 1940s) is listed in various places (under >'clock rate') as being 'async'. (And - annoyingly - those listings then don't >provide an effective instruction rate for the sake of comparison). > >I've been curious as to more precisely how the timing was accomplished in that >(those) machines. Offhand, I suspect you still end up with delay elements in >the design at various points to ensure some group (worst case) of >signals/paths >are all ready/stable at some point and you end with a more-or-less 'effective >clock rate' anyways and don't gain much. > >Such all started with ENIAC didn't it?, which - based on what I've been able >to find/read - could be described as an async design. >Was async still being discussed in the 60's? I worked on some "non-clocked" logic designs for a little company called Theseus. As far as I know they're still in business. It's been a while, so my memory is hazy and it was definitely unconventional design. The basic scheme (IIRC) was to use two wires per bit of information. Three of the four possible states were used. '0' and '1' were two of the states and 'ready' was the third state, except I don't think they called it 'ready' but that'll do for this discussion. When you reached a set of registers (flops) in the logic (say a grouping of 8 bits for a bus) you'd have 'acknowledge' logic which would would signal back upstream that it was ready for the next computation. It depended on all eight registers reaching a data state (0 or 1) before it signaled ready back upstream. Then and this is where I get hazy, all the registers would get reset to the ready state before the next set of data is processed. I think. It really has been a while. So, in practice, you have 2 to 4 times as much logic because you have two wires per bit plus acknowledge logic flowing back upstream. On the other hand, if nothing is being processed, then your circuitry is idle and not switching. This can save a bundle of power depending on the application. Additionally, the logic pipeline can operate as fast as it possibly can, without being held back by a clock. So in some cases one gains speed. And you don't have to worry about routing finicky clocks all over the chip. Still, you have the overhead of those acknowledge signals. Plus, being an unconventional logic, there are not sophisticated tools and libraries available, so it takes longer to design for and requires more design discipline from the designer. If you applied the same amount of effort and discipline to conventional design, you might end up with something just as good or better, but the non-clocked logic paradigm forces the extra effort. 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? Jeff Walther

19 years

Some more PCWorld "best of" chatter

by cclist＠sydex.com

http://tinyurl.com/kqzt6 Offered only in the spirit that it's OT for vintage computers, not for the content. Cheers, Chuck

19 years

semiconductor mfr. logos page

by rtellason＠verizon.net

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. Then in the past few days I got a request from one other correspondent who was looking for similar info, and pointed him at the page, which he was nicely impressed with, and at the same time dug around in my pile of downloads for some more of them I'd snagged since then. I then put this all together, and have uploaded the result, which can be seen here: http://www.classiccmp.org/rtellason/logos/semiconductorlogos.html and which is now also linked through my parts pages at: http://www.classiccmp.org/rtellason/parts-index.html Perhaps some of you will find this information useful. -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, a critter that can be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin

19 years

Need quantity of old school PC monochrome adaptors ($$$)

by dastar＠vintagetech.com

I'm in need of 10 monochrome adaptor cards for the PC. I'll pay $10 each in any quantity plus shipping. Please send your offerings directly to me. I do not read the list. I need these ASAP. Thanks! -- Sellam Ismail Vintage Computer Festival ------------------------------------------------------------------------------ International Man of Intrigue and Danger http://www.vintage.org

19 years

Group buy for homebrew CPUs

by compoobah＠valleyimplants.com

Jeff quipped >Does that mean that you *have* figured out a way to solder BGA into >place at home? It means that I haven't been able to pull any chips to practice with yet.

19 years

Need quantity of old school PC monochrome adaptors ($$$)

by compoobah＠valleyimplants.com

Mike sayith: >Is it not rude to presume that we all subscribe to this list so that we >can read and try the fill the urgent requests of others who post to the >list but won't bother reading it? In general, probably, but I'd be inclined to give Sellam a special dispensation - he was an active listmember for quite some time and hopefully will be again when his (daughter|son, can't remember) grows up a bit. Phenomenal resource, like Tony.

19 years

Tape Drive & Tape Archival questions...

by aliensrcooluk＠yahoo.co.uk

--- Don <THX1138 at dakotacom.net> wrote: > Tony Duell wrote: >> snip << > > > > I've had blets turn to a sticky rubber blob (lik e > the rollers in the > > other thread), then you can't match it up. > > I've only seen problems with "rubber feet" -- > especially on > Sun gear -- disintegrating. And, they end up > messier than > a wad of chewing gum that has been sitting in the > summer > Sun for a day... :-( > > Don I have had similar problems with the "feet" on some of my oldish consoles (I would say old but I feared people would think of the Atari's and such from the early 80's). One "foot" on the bottom of my SNES turned half to mush whilst the other three "feet" are perfectly fine! Not sure what caused it to happen... but as long as the SNES works I'm more than happy ;) Regards, Andrew B aliensrcooluk at yahoo.co.uk

19 years

Group buy for homebrew CPUs

by trag＠io.com

>Date: Fri, 11 Aug 2006 18:39:52 -0500 >From: Scott Quinn <compoobah at valleyimplants.com> >The really annoying thing about BGA is that I haven't figured a way to >desolder and reuse chips. Very vexing. Does that mean that you *have* figured out a way to solder BGA into place at home? Jeff Walther

19 years

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test-drb August 2006