test-drb

test-drb@ccmp.vtda.org

101090 discussions

by technoid6502＠gmail.com

Apropos of nothing, I've been confuse for some time regarding maximum clock rates for local bus. My admittedly old information, which comes from the 3rd ed. of "High Performance Computer Architecture", a course I audited, indicates a maximum speed on the order of 1ghz for very very short trace lengths. Late model computers boast multi-hundred to multi gigahertz fsb's. Am I wrong in thinking this is an aggregate of several serial lines running at 1 to 200mhz? No straight answer has presented on searches online. So here's the question. Is maximum fsb on standard, non-optical bus still limited to a maximum of a couple of hundred megahertz, or did something happen in the last decade or two that changed things dramatically? I understand, at least think I do, that these ridiculously high frequency claims would not survive capacitance issues and RFI issues. When my brother claimed a 3.2ghz bus speed for his machine I just told him that was wrong, impossible for practical purposes, that it had to be an aggregate figure, a 'Pentium rating' sort of number rather than the actual clock speed. I envision switching bus tech akin to present networking, paralleled to sidestep the limit while keeping pin and trace counts low.....? Something like the PCIe 'lane' scheme in present use? This is surmise based on my own experience. When I was current, the way out of this limitation was fiber-optics for the bus. This was used in supercomputing and allowed interconnects of longer length at ridiculous speeds. Thanks for allowing me to entertain this question. Though it is not specifically a classic computer question, it does relate to development and history. Best, Technoid Mutant (Jeff Worley)

7 years, 7 months

Vintage-computing relevant IOBCC entry

by jnc＠mercury.lcs.mit.edu

> From: Bill Degnan > I attempted to port the same version of unix to an rl02 disk pack and > to run on an actual 11/40. I was able to get ir to boot up to the # > prompt but my system does not have a working EIS card to proceed any > further. I"m incredibly surprised that you got to the prompt! First, the V6 RL bootstrap uses ASH, part of EIS. And then the C compiler makes extensive use of EIS instructions, so anything in C (the OS, 'init', 'sh', etc) may have EIS instructions in it. Noel

7 years, 7 months

Data General Eclipse microcode manual

by peter＠vanpeborgh.eu

Guys, Do any of you know where I could get hold of DG document(s) describing the microcode of their Eclipse family. It was wide yellow manual with brown plastic ring binding. It brings back happy but foggy memories. "The Soul of the New Machine"(book) tells me that the instruction set was built from the microcode by some genius overnight. Probably an urban myth! Who knows. Many thanks, peter

7 years, 7 months

Microcode, which is a no-go for modern designs

by bygg＠cafax.se

> Few people (but most are right here) can recite PI to enough digits to > reach the level of inaccuracy. And those who believe that PI is exactly > 22/7 are unaffected by FDIV. (YES, some schools do still teach that!) Why remember the digits, when a small program can provide them? +0un qn"E20Un' 0Uh 0uv HK Qn<j 0uq Qn*10/3Ui Qi<\+2*10+(Qq*qi)Ua 0LK Qi*2-1Uj Qa/QjUq Qa-(Qq*Qj)-2\10I$ Qi-1ui> Qq/10Ut Qh+Qt+48Uw Qw-58"E48Uw %v' Qv"N:Qv,1^T' QwUv Qq-(Qt*10)Uh> :Qv,1^T !Can you figure out what this macro does before running it? It was written by Stan Rabinowitz with modifications by Mark Bramhall and appeared as the Macro of the Month in the Nov. 1977 issue of the TECO SIG newsletter, the "Moby Munger". For information on the TECO Special Interest Group, write to Stan at P.O. Box 76, Maynard, Mass. 01754! --Johnny

7 years, 7 months

PDP-11/45 RSTS/E boot problem

by jnc＠mercury.lcs.mit.edu

> I don't recall off the top of my head whether the location of that > shared block of memory is in the per-process swappable kernel data > (which is included in the process core dump). So I checked, and the swappable per-process kernel data does in fact include pre-computed contents for all the memory management registers, so we'll be able to see (from the process core dump) where the code and data segments were. On another front, that error message ("Memory error") is produced when a process gets a 'memory management trap' (trap to 0250). This could be caused by any number of things (it's a pity we don't know the contents of SR0 when the trap happened, that would tell us exactly what the cause was). With working hardware+OS, it's usually the result of a bad pointer in the program. In a tested program like 'ls', I don't think that's the case. It's most likely caused by faulty memory, but it's also faintly possible that the MMU has an issue. I'll look at the process dump a little later today, and see if I see anything of significance. Noel

7 years, 7 months

Bogus "account hacked" message

by cctalk＠beyondthepale.ie

About two hours ago, I received an email to the address I only use for cctech/cctalk. It claimed my email account had been hacked and threatened all sorts of dire consequences if I didn't deposit $1000 in bitcoins in some place within 48 hours. I am 100% certain that the claims in the message are completely bogus and none of the threats will be carried out. It is likely that email addresses belonging to other list members are also to be found wherever my email address was scraped from so I just wanted to warn other list members about this scam in case they receive similar emails. (I received the scam email directly, not via the cctech listserver). Regards, Peter Coghlan.

7 years, 7 months

Vintage-computing relevant IOBCC entry

by lproven＠gmail.com

/* You are not expected to understand this. */ https://www.ioccc.org/2018/mills/hint.html -- Liam Proven - Profile: https://about.me/liamproven Email: lproven at cix.co.uk - Google Mail/Hangouts/Plus: lproven at gmail.com Twitter/Facebook/Flickr: lproven - Skype/LinkedIn: liamproven UK: +44 7939-087884 - ?R (+ WhatsApp/Telegram/Signal): +420 702 829 053

7 years, 7 months

PDP-11/45 RSTS/E boot problem

by jnc＠mercury.lcs.mit.edu

> From: Fritz Mueller PPS: > I could work to extract the core file I just checked, and the binary for the 'ls' command is what's called 'pure code'; i.e. the instructions are in a separate (potentially shared) block of memory from the process' data (un-shared). I don't recall off the top of my head whether the location of that shared block of memory is in the per-process swappable kernel data (which is included in the process core dump). I'll check tomorrow, when I'm not sick as a dog (pretty miserable right at the moment). It would be east to mod the OS to print all that info when that illegal instruction trap happens - but that will change the size of the OS, so will probably change the location the process is at; so that might cause the symptoms to change. Ditto for recompilling 'ls' to make it a unified blob. > Assuming that doesn't create another core file... :-) :-) Don't worry, we'll nail it! Noel

7 years, 7 months

Anyone want an irman (Infrared to serial dongles)

by guykd＠optusnet.com.au

At 11:05 PM 8/01/2019 +0000, you wrote: >While tidying up I've found a few Irman infrared to serial dongles > >https://web.archive.org/web/20060314052558/http://www.evation.com/irman/ind… > >they connect via a 9 pin serial plug and then convert any consumer >remote IR signals they receive into serial. > >No additional power required, good wide angle reception, open source >driver still available > >https://sourceforge.net/projects/libirman/ > >Could make an interesting project for anyone who wants to control >their VAX / S-100 / homebrew retro board with a serial port via a >remote :) > >The company making them went away about a decade ago, so I'm counting >that as in retro territory. > >I have four for the price of shipping if anyone is interested, based >in London/UK. > >(Around 2000 we had an office music system based around a DNARD/Shark >running mserv & irman where everyone had a random remote at their desk >and could use it to rate/skip/queue something they liked, and the >system generally trid to pick from music which most of the people >currently connected liked... ahh, fun days :) > >David I'll definitely take one. Or preferably two, if that doesn't clash with anyone else wanting one. I'll send my address via private email. Can you accept Paypal for the postage? Guy

7 years, 7 months

Anyone want an irman (Infrared to serial dongles)

by couryhouse＠aol.com

Chuck we would like a couple..? ed at smecc Sent from AOL Mobile Mail On Tuesday, January 8, 2019 Chuck Guzis via cctalk <cclist at sydex.com; cctalk at classiccmp.org> wrote: On 1/8/19 3:05 PM, David Brownlee via cctalk wrote: > While tidying up I've found a few Irman infrared to serial dongles > > https://web.archive.org/web/20060314052558/http://www.evation.com/irman/ind… > > they connect via a 9 pin serial plug and then convert any consumer > remote IR signals they receive into serial. I just posted on github a little project that takes a cheap surplus (my last ones cost $5 NOS) IBM iPoint IR keyboard and converts it to PS/2 keyboard protocol using a cheap STM32F103 "Blue Pill" and a 3-terminal 38KHz IR receiver.? I'm currently writing the USB version which will support the "nipple mouse" as well. The keyboards aren't bad--they're made by Silitek ca. 1992 and have a decent feel for a rubber dome keyboard. The point is that with modern MCUs, any IR stuff is easy-peasy.? My little Chinese LCR tester even reads and displays IR codes. --Chuck

7 years, 7 months

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test-drb