test-drb December 2001

test-drb@ccmp.vtda.org

243 participants
1096 discussions

by pechter＠ureach.com

---- On Wed, 19 Dec 2001, Eric Dittman (dittman(a)dittman.net) wrote: > At the place I picked up my 9-track tape drive they had a Nile 150 > system with storage unit that they're looking to unload. I don't > know anything about the system (nor did they, other than the guy > telling me about the system said it has MIPS R4x00 CPUs). > -- > Eric Dittman > dittman(a)dittman.net > Check out the DEC Enthusiasts Club at http://www.dittman.net/ Boy, I never worked on the Nile's but I did on the MIS-S Pyramid DC/OSx boxes. Slick stuff. As an old DEC and Pyramid guy I was amazed how they had to kludge clustering into Unix boxes and how Sun took most of the stuff they're doing from Pyramid's early work in the area. Bill Pechter bpechter(a)monmouth.com

23 years

M8650 async board problem

by pete＠dunnington.u-net.com

Now I'm really puzzled. After spending the evening playing with my M8650 serial board, and armed with the pinouts this time, I still have an interrupt problem. The fault is that the usual operations don't disable the interrupt from the board. As far as I can see from the PDP-8/E Maintenance Manual, pressing CLEAR on the panel should enable the interrupts, while issuing a KIE instruction with AC11 = 0 should disable them. Have I understood this correctly? Looks like it does the reverse (I ought to have checked that KIE with AC11=1 disables it on this board, but I forgot, and it's too cold and late to go back to the workshop right now. I'll do it tomorrow). The fault must have been noticed at some time in the past, as someone has cut the trace to CP1 (INT RQST L output to the bus). If I bridge the cut, the interrupts remain on all the time, which I suspect is why I can't get FOCAL to run. At this point I should mention that my M8650 isn't labelled as a -YA version, though it has the 19.66MHz crystal and the jumpers to run at 300 baud. It has several very neat modifications made with green wire-wrap wire, tacked down in the manner of DEC ECOs, but nothing that looks like it alters the interrupt flipflop operation. The board etch says "M8650 D", "ASYNCHRONOUS DATA CONTROL", "PCC 3874" and it has "441E" stamped on one of the magenta handles. According to the Maintenance Manual, INIT H is buffered and inverted, and fed to the SET input of the flipflop (which is a 7474). Well, on mine it's fed to the CLR input. However, according to the MM, the "1" output (which I'd call the Q output, pin 9) enables interrupts if high, and is available at CB1, the test point. On mine, pin 8 (not-Q) is connected to CB1 and used to enable interrupts by driving one side of E33. So far so good, if a little surprising. But DATA 11 is fed to the D input as per the MM (buffered and gated with I/O PAUSE L but not inverted). So KIE with AC11 = 0 clears the flipflop, which sets not-Q, which enables interrupts. This is not what the diagnostics expect, and predictably, they fail, halting at the location that means the interrupt is not turning off when it should. BTW, I assume that a high level on DATA 11 corresponds to a logic '1'. Should I just swap the connections to the SET and CLR, and Q and not-Q on the 7474? Or am I missing something? -- Pete Peter Turnbull Network Manager University of York

23 years

Fwd: Re: pdp-11/34 for rescue

by jhellige＠earthlink.net

Here's more information regarding the PDP-11/34 that I posted last night. Again, please reply to the poster. Jeff >Status: U >To: Jeff Hellige <jhellige(a)earthlink.net> >From: day-o(a)cavtel.net >Subject: Re: pdp-11/34 for rescue >Date: Wed, 19 Dec 2001 13:38:24 GMT > >Jeff, > Thanks for the quick response. It's located in Hampton, Virginia and >contained in a logoed model H960 cabinet with an 861c power supply and 7 >disks of questionable worth. > >Owen Day > > > >--------------------------------------------- >This message was sent using Cavalier Telephone WebMail. >http://www.cavtel.net -- Home of the TRS-80 Model 2000 FAQ File http://www.cchaven.com http://www.geocities.com/siliconvalley/lakes/6757

23 years

Heath h-8

by csmith＠amdocs.com

> -----Original Message----- > From: Bob Brown [mailto:bbrown@harper.cc.il.us] > Where is this h8 web site? I saved an H8 from the landfill > a while back.. > just a system, no peripherasls...seems to work, but I don't > know what to do > with it..no documentation at all. The one I've found is: http://people.ne.mediaone.net/davidwallace2000/ Click on the heathkit logo... Also he has a link to another H-8 emulator for Macintosh. At any rate, it looks like a fairly simple machine to me. My story is the same as yours. It was brought to me because one of the people at the scrapyard thought I might like to have it. Anyway, the console interface is remarkably intuitive. You can use the keypad to view or set memory addresses/registers in octal. One could just key a program in 8080 machine language, set the program counter and hit "go." The system would then do as you'd told it. If only the computers most people use today were that flexible and user-friendly. Regards, Chris Christopher Smith, Perl Developer Amdocs - Champaign, IL /usr/bin/perl -e ' print((~"\x95\xc4\xe3"^"Just Another Perl Hacker.")."\x08!\n"); '

23 years

Speaking of PS/2s...

by doc＠mdrconsult.com

Hi, all. I had sort of gotten the impression that PCs don't count on this list. I have a 5870-121 that I snarked recently, with 4 megs of RAM and a 120M ESDI drive. I'm wondering what I want to put on it as OS. I have plenty of Linux/NetBSD critters. I was thinking OS/2, but I threw v3.0 Warp on Saturday night, but it's slow as dirt with 4 megs. Oh, yeah. It had the original reference disk in the floppy drive. I think that's really why I bought it. I also have a Model 25 386dx/16 which is one of my favorites. It had a token-ring ISA adapter, as well as an 8-bit ethernet adapter I can't ID, no hard-drive, and was set up to netboot. I finally found the J-leg 387 for it, stuck in a 500m drive with EZ-drive, and run PC-DOS & Lemmings, mostly. Main questions are, how uncommon are they (I know how cool they are), is either one worth anything, and is there a contemporary Unix that'll run on the model 70? Um, that's actually available I mean. All I need is another Ultrix quest. Corollary questions: I mentioned earlier that I've found PS/2 adapters in 7012 series RS/6ks. I still have 'em. The 8514/A with the 512k daughterboard is recognized in the model 70 by the reference utility, but Warp pukes on it, and insists on 640x480x16 VGA settings. Did I miss something? Do I need to "copy the options disk" even though Setup already sees it? And, I have the Orchid board with the oddball video output. Are there cables for that? Will it drive a standard multi-sync display? Is it worth messing with? It's so nice to have real brains to pick. Doc

23 years

Rainbow 100+ available.

by mtapley＠swri.edu

Hey, all you prospective Rainbow owners need to check comp.sys.dec.micro ASAP. Someone trying to get rid of a RB100+, with a *hard drive*, VR241 color monitor, LK201, and LA-50 printer. I can help with docs and software. - Mark

23 years

MITS 2SIO serial chip?

by ajp166＠bellatlantic.net

From: Ben Franchuk <bfranchuk(a)jetnet.ab.ca> >One real problem with the Z80 is that a there is a lot of >unused/undefined >instructions because of the complex instruction set, that have been >decoded >and used in software. This has a impact if you are not using a real chip >but a emulator of some sort. Most are either redundant or no-ops, those at are useful most good z80 emulators have them as they are copied in competitors z80s. Allison

23 years

MITS 2SIO serial chip?

by ajp166＠bellatlantic.net

None of that means much. At the same sped which one will do a long list of benchmarks faster is the only one that counts in the speed derby and which one is cheapest to implement for the specific case is likely number one. Allison -----Original Message----- From: Richard Erlacher <edick(a)idcomm.com> To: classiccmp(a)classiccmp.org <classiccmp(a)classiccmp.org> Date: Thursday, December 20, 2001 4:21 AM Subject: Re: MITS 2SIO serial chip? >If you run a 20 MHz Z80 against a 20 MHz 6502, you'll find the 6502 performs WAY >(3x-5x) faster than the Z80. It's difficult to base a comparison on clock rate >alone. All 6502 memory cycles take 1 clock tick. Z80 memory cycles, aside from >M1, take 3 clock ticks, with no wait states in use. If you run the 6502 at a >rate that fully utilizes the memory bandwidth at a rate such that the Z80 can >perform an M1 in the same amount of time, without wait states, the 6502 will >always be faster, because it's running faster. The Z80 uses 1-1/2 clock ticks >to execute its instruction fetch. If that's to be memory access window for each >processor, and you run them both from static memory, and you allow minimal >recovery time, e.g. use 10-15 ns memory, (just for the comparison) then you can >use a 20 MHz Z80 and a 20 (actually 14) MHz 6502, and clock the 6502 with a 25ns >low, 75ns high clock, and drive the Z80 with a square 20 MHz. That will be a 10 >MHz clock for the 6502 and a 20 MHz clock for the Z80. I'd submit that the 6502 >will still run rings around the Z80, since it is still going to be cycling >memory at an average of 200 ns per cycle, while the 6502 does it a 100 ns rate. > >Surely a better comparison can be arranged. > >Dick > >----- Original Message ----- >From: "ajp166" <ajp166(a)bellatlantic.net> >To: <classiccmp(a)classiccmp.org> >Sent: Wednesday, December 19, 2001 4:46 PM >Subject: Re: MITS 2SIO serial chip? > > >> >Ben Franchuk <bfranchuk(a)jetnet.ab.ca>: >> > >> >> what is the faster CPU -- A 6502 or Z80 style processor like >> >> the rabbit. >> >> >> Depends... >> >> For the same instruction execution rate (ignores clocks and cycles) >> the z80 is likely faster. However... if you have a 20mhz 6502 and >> a 10mhz z80 it gets muddier with the 6502 being the faster. And >> if you know one better than the other you can certainly exploit it >> all the more. In the end it's not which one does a task faster, it's >> what one you can code the task for faster. >> >> Sorta like asking apples or oranges. >> >> Allison >> >> >> > >

23 years

Nile 150

by DAW＠yalepress3.unipress.yale.edu

! From: Chris Kennedy [mailto:chris@mainecoon.com] ! ! ! David Woyciesjes wrote: ! ! > How big is this thing? And no ideas as to what it is? ! ! It's a Pyramid SMP Unix box from around '96. Runs Simix, a ! SVR4-derived Unix. Typically used as big-ass (as in ! terabyte range) database servers. ! ! There may be a Linux port for the architecture, but ! I'm too lazy to check. ! ! Size clearly depends on configuration, but "not small" ! would be a good guess. ! ! Anyone know where this jewel is located? ! ! Cheerz, ! Chris. I must say, depending on location, I am definitely interested... --- David A Woyciesjes --- C & IS Support Specialist --- Yale University Press --- mailto:david.woyciesjes@yale.edu --- (203) 432-0953 --- ICQ # - 905818

23 years

C64 vs. Spectrum (was Re: Hardest to Find Classic Computers (SX64))

by acme_ent＠bellsouth.net

> From: Cameron Kaiser <spectre(a)stockholm.ptloma.edu> > Actually, there is some resentment of Commodores in some quarters. Besides > the usually friendly rivalry between Spectrum and 64 owners, I've encountered > some real vitriol when I bring up 64s to certain other classic computer > groups who shall currently remain nameless. Don't go near comp.sys.sinclair. "Commode" users get slammed there on a regular basis -- and hard. > I suppose their justification is > that the C64 crammed their system out of the market, and as a Mac user, I > do have *some* sympathy :-), but still ... The general opinion seems to be that the C64 folks stole the best games >from the Spec, and cut price to run Sinclair out of the market. Glen 0/0

23 years

Jump to page:

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

2003

2002

2001

2000

1999

1998

1997

test-drb December 2001