test-drb

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101090 discussions

by seefriek＠gmail.com

Is there an equivalent to the DSV11 for Unibus? Or other quick Unibus sync serial that my Google-fu isn't good enough to find? The DMC11 looks like it can do 56Kbps over V.35, which is better than the 19.2kbps on the DMF32, but it would be useful to be able to push to 256Kbps (or faster). I'm particularly interested in doing HDLC. KJ

9 years, 7 months

Data General Nova Star Trek

by shermanfoy＠att.net

have discussed w/ Jim: I have a 240 Euro connector bench transformer meant for this.

9 years, 7 months

Vintage computer ads...

by COURYHOUSE＠aol.com

very bogus with the hp 150 business system and they guy claims the 9121 dual floppies was a hard drive.... Ed# _www.smecc.org_ (http://www.smecc.org) In a message dated 4/20/2016 7:47:24 A.M. US Mountain Standard Time, oltmansg at gmail.com writes: On Wed, Apr 20, 2016 at 9:37 AM, geneb <geneb at deltasoft.com> wrote: > https://www.youtube.com/watch?v=7T1IYdjOpYE > > The video is an hour long, but you can skip around. It includes ads for > machines like the ITT Xtra, IBM PC Jr, etc. The Hayes Smartmodem ad is > just atrocious. :) There's even ads for IOMega drives and the Promethus > Pro Modem... > > Is that Bryan Cranston a la Breaking Bad in that video??? Sure looks like him.

9 years, 7 months

Accelerator boards - no future? Bad business?

by swiftgriggs＠gmail.com

Remember all the accelerator boards for the Mac, Amiga, and even PCs in the 90's ? I've often wished that I could get something similar on my older SGI systems. For example, fitting an R16k into an O2 or doing dynamic translation on a 4.0Ghz i7. I'm most familiar with the Amiga accelerators. I suspect those who produced them were helped out greatly by a couple of factors. One is that the hardware specs were very well known and full schematics were available for most (all?) Amigas. I doubt the same is true of SGI machines. The other is that many Amigas had processor "slots" (with edge connectors) rather than some tiny fiddly ball-grid array etc... but I'm not a EE; so maybe that's bunk. When I look at these boards they seem like they'd be a LOT of work to develop and produce. I wonder how they were even economical to make back in the day. Plus, now the user base will probably only shrink. It's not a great business model for a hard-to-produce item. It doesn't keep my techno-lust from wanting it, though. So, here's the question. Is my dream likely to ever be possible enough that a boutique shop could pull it off and not lose their shirt on the production costs and R&D to do it ? I'm encouraged by things floppy emulators that are produced for these old machines. However, that's probably significantly easier to make than a CPU accel board. What do you guys think? -Swift

9 years, 7 months

Keys - Non-Ace was RE: ACE Key codes (xx2247 etc.)

by mhs.stein＠gmail.com

I finally found my micrometer; is there a cross-reference of pin # vs. depth or just a list of standard depths for ACE keys somewhere? m

9 years, 7 months

High resolution screens are great for typography - Re: Accelerator boards - no future? Bad business?

by jnc＠mercury.lcs.mit.edu

> From: Swift Griggs > it's (currently) a big hassle in Windows to get absolutely every font > to get bigger at once. Have you tried right-click on a blank spot on the desktop, 'Properties', 'Setting', 'Advanced'? The window that pops up allows you to change i) on older Windows, _all_ font sizes (options are 100%, 125%, and custom) at once; ii) on newer Windows, the size of _everything_ (which includes images, I think). Noel

9 years, 7 months

bit slice chips (was Re: Harris H800 Computer)

by jnc＠mercury.lcs.mit.edu

> From: Brent Hilpert > I'd say the 74181 (1970) deserves a mention here. Simpler (no register > component, ALU only) but it pretty much kicked off the start of > IC-level bit slicing. Yes, it was used in quite a few machines. Among the PDP-11's alone, it is found in the -11/45, /05, /40, /04 and /34, to name a few that I checked quickly, and almost certainly others too (e.g. /70). Noel

9 years, 7 months

Accelerator boards - no future? Bad business?

by jnc＠mercury.lcs.mit.edu

> From: Jules Richardson > I think my personal view is that I'll consider modern replacements to > things when it's impossible to use the originals - but not simply for > reasons of speed, cost, convenience. This sounds like it's not _that_ far from my position, which is that I am against building modern equivalents for "stuff that is still available and perfectly functional". >> running the disks ... risks damaging what are effectively museum >> pieces. > There I'd just say run them until they break and can't be fixed, and > then they can become static museum exhibits. The problem with that is that I feel that it conflicts with what I feel one of our main goals ought to be, which is to preserve these machines in running form, for history and the education of future generations. Yes, even powering them on risks a failure, but most failures are repairable. A crashed head, if you don't have spares, is pretty much un-fixable (there's a whole manufacturing complex needed to create them, which is now gone, and one can't substitute an alternative part). So I'd run them as little as possible - and a modern solid-state alternative really helps with that. (BTW, there's a big debate in the museum world over this sort of topic: some places won't do any cleaning and fixing of antique objects, retaining them exactly as they were, and living with the degradation of plastics, etc; others do restoration, but mark what was done, and make it reversible if possible; others go all out and restore things to 'like new'. I'm kind of in camp II, myself.) There's also a practical down-side to the 'run it as a matter of course till it fails forever' approach; if one has packs for that drive which one wishes to read or write, that's no longer possible once the drive is roached (although someone else could do it for you, but that's not necessarily a desirable option). And of course, with the drive dead, the machine may not be runnable unless one adds a modern alternative - and if one's willing to do that _after_ the drive is fried, why not before? > From: Swift Griggs > I might be laughed at for wanting a Fiero-Ferrari For a good time, Google 'Jerrari'! :-) Noel

9 years, 7 months

pdp8/e problems

by Mark＠Misty.com

Hi, Is there anyone with a good set of 8/e prints who could help me narrow down some troubles? My 8/e was working a few years ago, but now it's developed some problems. It seemed to work fine for about the first 2 minutes that I tried it, but then it developed these two symptoms: - Most of the time, upon power up, LOAD-ADDR clears all the random address lamps, but will not take an address, just all 0s. Occasionally when I power it up, LOAD-ADDR will permit me to load an address, and see it's contents as it should. I can then enter other addresses, hit LOAD-ADDR, and get consistent results looking around at random data in different memory addresses. - Regardless of whether it's in the broken load-addr state above or not, hitting DEP or EXAM just turns on the RUN lamp, and it's then stuck with RUN on, and non-responsive to any other front panel actions. This happens irrespective of the position of HALT. I then power-cycle it and it is back in either broken or working LOAD-ADDR mode as described above, usually broken. So far, the only M8330 prints I have found are extremely fuzzy, so I cannot make out the IC identifiers or match them up to the equally fuzzy schematic. By board-inspection I identified the 74S74 "run" flip-flop, and in fact I can un-stick the RUN state by briefly grounding CLR, but still cannot DEP or EXAM from the front panel -- it gets stuck back with RUN on if I hit either DEP or EXAM again. The power supply voltages are right-on. I've reseated and repositioned the boards. The connectors are very clean. Wiggling boards doesn't change any of the symptoms. Wiggling switches doesn't affect anything. This is a very clean 8/e. Mark -- Mark G. Thomas (Mark at Misty.com), KC3DRE

9 years, 7 months

bought in error - 1W Resistors

by binarydinosaurs＠gmail.com

Folks, Thanks to an ordering SNAFU by me I have some 1W resistors spare at 1K, 10K, 220R and 330R. 20 of each. They only cost ukp1 per bag so it's not worth me trying to send them back. Anyone? Or do I just bung them in my spares box and use them ad-hoc... -- adrian/witchy Owner of Binary Dinosaurs, the UK's biggest home computer collection? www.binarydinosaurs.co.uk

9 years, 7 months

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