test-drb April 2016

test-drb@ccmp.vtda.org

203 participants
299 discussions

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

8 years

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

8 years

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

8 years

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

8 years

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

8 years

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

8 years

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

8 years

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

by jnc＠mercury.lcs.mit.edu

> From: Dennis Boone >> it says "Chicago Lock Co" and "GRB 2" > Aha. > Cut 215 on Ilco S1041T. You were able to deduce that from the "GRB 2"? Is that authoritative? If so, I'd like to add it to the 11/05-10 page on the Computer History Wiki. Also, I have an original XX2065 (Data General) which I have no use for; if anyone has an XX2247 they'd like to trade for it (new is fine too), please let me know. Noel

8 years

Data General Nova Star Trek

by erik＠baigar.de

Hi Jim, regarding reading the StarTrek paper tapes I spent some time on the weekend to rework my SPT11A manual reader - I got this from an eBay auction and it was an accessory for some military receiver (probalby to read in some codes). It had a fimrwaere which refused to communicate with a simple terminal program, so I reverse en- gineered the hardware and replaced the original ROM it by an own firmware which simply sends the contents read from PPT to the PC via its RS232C... http://www.baigar.de/vintage/SPT11A-mod-Internal.jpg So I'd offer sending this to you as an item on loan to read in your tapes and you return it afterwards? I tested it with some data and it works well (just slowly pull the paper tape through the reader and use e.g. putty to log the binary serial output). After turning on the reader there is a short welcome message to verify the serial connection (9600,8N1). The only question is, whether you can handle the EU style power supply shown in the picture... http://www.baigar.de/vintage/SPT11A-mod.jpg I ordered USB->RS232C converters and if you have some more time, I'd attach one of them to the reader not only doing conversion but also supplying the converter with power from the PC. Addidionally you should send me your physical address via PM so I can prepare for shipping... Best regards from Germany, Erik. On Mon, 18 Apr 2016, jim s wrote: > > > On 4/18/2016 12:19 AM, Erik Baigar wrote: >> >> >> Hi Jim, Dear Sherman, >> >> thanks for the update. I wish you the very best for digitizing the >> tape. I can offer reading it using a Facit N4000 (speed can be configured >> down to 50cps, i.e. around 10cm/s). I also have got a manual reader >> which unfortunately is broken: I would have to generate a new 80C51 >> chip with the right firmware (not a big issue, but not possible over >> night). I can offer fixing this and lending it out to you in >> two or three weeks... >> > I'd be glad to help with shipping on that and would use it. I don't have any > fanfold samples to send to you for testing, but would be glad to have a hand > version to feed this thru. >> I'd be really interested in getting hands on a copy to run on my >> Rolm computers. Are you sure, that there is only a singel tape? > There are 47 individual tapes in the set. All from 1/4" of fan fold width to > about 1 1/2" of fanfold width. > > I will put up my photographs and videos later today and reply again with that > information on my blog. >> As mentioned I have got one tape of a two-tape binary distribution >> of the StarTrek. >> >> Best Regards from Germany, >> >> Erik. >> >> >> >> On Sun, 17 Apr 2016, jim s wrote: >> >>> Here is an update on the tape. It is a box of 47 tapes. We got a >>> volunteer from Charles Anthony to do a video reader for it. >>> >>> I have a video I can share of that tape if that is of interest. I was >>> hoping that it was going to be a basic source tape distribution, but on >>> looking at it, that doesn't fit with what I can read by eye on the tape I >>> read, so I bet it is a bunch of binaries. >>> >>> The tape is fanfold and will need a very careful handling to read it so we >>> will proceed carefully. It is pristine now, doesn't look like it was ever >>> read. >>> >>> I will let you know if we need help, but am going to look for a hand >>> optical reader somewhere for loan or build and attack it that way. >>> >>> It has writing on the box that leads me to think it is from a user group >>> for DG of some sort if that helps you identify the source of it. >>> >>> thanks >>> Jim >>> >>> >>> On 4/16/2016 3:04 AM, Erik Baigar wrote: >>>> >>>> Hi Jim, >>>> >>>> just out of curiosity: Did you have got a look at the DG Star >>>> Trek? Is there a chance to get a copy of the tape? >>>> >>>> If you need assistance in reading the tape, just drop me >>>> a note... >>>> >>>> Best regards from Germany, >>>> >>>> Erik. >>>> >>>> >>>> On Fri, 8 Apr 2016, Erik Baigar wrote: >>>> >>>>> >>>>> Hi Jim, >>>>> >>>>> short version: Yes, I can confirm existence of such a software and >>>>> I'd be highly interested in a copy. Of course I can >>>>> offer digitizing it ;-) >>>>> >>>>> longer version: I am preserving various Rolm (later Loral) 16 bit >>>>> machines which are hardened, military machines widely comaptible >>>>> to the DG hardware (1602 compatible to Nova and MSE14/Micro is the >>>>> hardened Eclipse). If interested, have a look at my logbook... >>>>> >>>>> http://www.baigar.de/TornadoComputerUnit/TimeLine.html#HDDsim >>>>> >>>>> ...datecodes 10/20/2014 to 12/15/2014 and 2/3/2015 to 2/28/2015. >>>>> Together with two friends (both maintaining a 1602B and native >>>>> DG hardware) we built a harddisc simulator to run advanced >>>>> software (e.g. RDOS). During my efforts I rescued some paper tapes >>>>> from Rolm (diagnostics)... >>>>> >>>>> http://www.baigar.de/TornadoComputerUnit/EB-RolmTapes.jpg >>>>> >>>>> ...and among these serious, mighty tapes was one labeled >>>>> "Star Trek 1/2". I digitized it, but without the second part >>>>> it is of nut much use, so I am sure that such a game existed >>>>> for DG hardware. From the first tape I can tell, that it is >>>>> not just the BASIC listing, but native machine code and there >>>>> is a copyright message dating 1969-1973 ;-) >>>>> >>>>>> The tape pile is fanfold about 10" across in a DG box specially made >>>>>> for such use. >>>>> >>>>> On some occasions I had trouble reading the 30+ years old >>>>> oiled black tapes due to some holes on the folds being >>>>> obscured at the from debris of the ageing paper... >>>>> >>>>> The very best from Germany, >>>>> >>>>> Erik. >>>>> >>>>> >>>> >>>> >>> >> >> >

8 years

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

by jnc＠mercury.lcs.mit.edu

> From: Dennis Boone > Haven't managed to id the 11/05 key yet. I have an original (which was used to make a ton of replicas for people a while back); it says "Chicago Lock Co" and "GRB 2". No idea what the latter means. The copies were made with Hillman Y11 and FR4 blanks (both work, but one has to be trimmed a bit, length-wise). Noel

8 years

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test-drb April 2016