test-drb December 2001

test-drb@ccmp.vtda.org

243 participants
1096 discussions

by pete＠dunnington.u-net.com

On Dec 26, 18:21, Ethan Dicks wrote: > --- Pete Turnbull <pete(a)dunnington.u-net.com> wrote: > > > It's not cool like core, but did anyone ever come up with a modern > > > battery-backed-up SRAM board? > > > > Yes, I've got one. It even has a connector to link to an interface in a > > PC, so you can squirt (or suck) data in (or out) directly. > > That's a cool feature. You got docs? Is this commercial or homebrew? > How about a digital picture? 75dpi scan? It's a commercial 4-layer board. The legend says "Tellima Technology Ltd (C) 1995", "PC03753". It has a couple of surface-mount KM68100 SRAMs, but the most prominent features are the two Actel 1020 FPGAs. It also has 6 x 8837 and 3 x 8838 interface ICs, a pair of 74HCT244's, 2 x 74HCT160 and a 74HCT161, a MAX695, a 16MHz oscillator, a 3V 1/2AA lithium cell, a littl daughterboard with some inteface chips, and the 26-way header for the PC interface. The PC interface is a small 4-layer ISA card "PC03285-C", with a couple of Actel 1010's, a few small SMDs, 2 x 74HCT160 and a 74HCT161, and a 26-pin header on the backplate. Interestingly, it also has space for a 132-pin SMD device, several smaller SMDs, eight ZIP devices, and a couple of 8-pin miniDINs. I don't have a scanner, at least not one that works. Nor a digital camera, except my Indycams, which aren't exactly high resolution. I'll see what I can do... -- Pete Peter Turnbull Network Manager University of York

22 years, 9 months

RSTS/E on a PDP 11/34?

by csmith＠amdocs.com

> -----Original Message----- > From: Sellam Ismail [mailto:foo@siconic.com] > Ah ha. Ok, so then my next question is, if I had some > version of RSTS/E, > could I read files on disks from other versions? Are they basically > interchangeable? I think it uses FILES-11/ODS-1, which means that you can share disks among RSTS/E systems and RSX-11 systems. VMS will also read and write them if I'm not mistaken. At least it should read them. VMS uses ODS-2 natively, though. I also have the FILES-11/ODS-1 spec in electronic form. Regards, Chris Christopher Smith, Perl Developer Amdocs - Champaign, IL /usr/bin/perl -e ' print((~"\x95\xc4\xe3"^"Just Another Perl Hacker.")."\x08!\n"); '

22 years, 9 months

add-on CPU load meters

by LFessen106＠aol.com

In a message dated 12/27/01 11:35:11 AM Eastern Standard Time, erd_6502(a)yahoo.com writes: > I found that. More than once. That's for an LED bargraph. I'm > looking for a circuit that operates an old-fashioned galvanometer- > style panel meter with a needle that swings from side-to-side. > > I can invent my own - a simple ladder D-to-A to produce a variable > voltage out of the parallel port. I was hoping to save the math > and use resistor values that someone else has calculated, but after > two days of searching, I guess I _will_ have to go do it myself. > > Somewhere in my junk boxes, I have some .5" tall by 1.5" wide signal > meters that I think I pulled from a dead CB radio, c. 1978 (pre-40- > channel). The plane of the needle swing is parallel to the floor, > and the needle has a 90-degree bend at the end, so you see a .2" > tall vertical line slide from left to right as the signal improves. > If I can find it, it'll mount perfectly in a 3.5" blank faceplace. > > Now to excavate the old parts! > > -ethan > > Well, please let us know if and how you get this working. I would love to have something like this as well! -Linc. In The Beginning there was nothing, which exploded - Yeah right... Calculating in binary code is as easy as 01,10,11.

22 years, 9 months

PDP8/A memory problems, what to do?

by pete＠dunnington.u-net.com

On Dec 26, 18:18, Ethan Dicks wrote: > > --- Pete Turnbull <pete(a)dunnington.u-net.com> wrote: > > On Dec 26, 14:20, Gunther Schadow wrote: > > > > > My first PDP-8 program is a memory test... > > > > Good idea. I meant to mention in my followup to Ethan, that the > > diagnostics are also available, at > > > > http://pdp-8.org/papertape/ > > Nice. Fortunately for me, I have several boxes of DEC diagnostic tapes > (nothing unusual, but I'll check my list against what you have) I don't deserve any credit for the tapes and docs online -- they're the fruits of serveral other people's labours :-) pdp8.org is Aaron Nabil's site, and David Gesswien provides the docs at www.pdp8.net > At the moment, I think I have an M865 that works and an M8650 that may > or may not work. If I'm forced to use 20mA, I guess I'll have to dig > up a genuine IBM 8-bit serial card and mod it to switch it to current > loop. You probably know you can use an M8650 in RS232 mode. If you don't have a BC01V cable wired for RS232, Doug Jones' site has an excellent diagram, and a useful document explaining how to set up the baud rate etc (BTW, the note about changing the capacitor value for baud rates other than 110 only applies to current-loop operation). How different is an M865? Is it only current-loop? http://www.cs.uiowa.edu/~jones/pdp8/hard8e/ -- Pete Peter Turnbull Network Manager University of York

22 years, 9 months

UnCursing the Darkness.

by pete＠dunnington.u-net.com

On Dec 26, 21:39, John Allain wrote: > I recently bought 2 each of all the white LED's that Jameco > sells. While *white*s are OT, they are nonetheless impressive. > The light density, efficiency, color, and longevity they have is > pretty amazing, to me anyway. Jameco rated them at 4 foot > candles at 20ma, which seemed a little 'opto'mistic. > I tried them out, and they reach near peak light at more like > 180ma, getting just noticeaby warm. At 250ma they are > 'uncomfortably' warm, hence question: > Did they really mean 20ma? at that proportion they're > putting out <10% peak, but 180ma is WAY above spec, > Jameco's spec anyway. So I guess Jameco's wrong? > Could I be loosing lifespan at this current? Maybe the > not-too-warm test is good enough? I had a look in my Farnell catalogue. Most of the white LEDs they stock are rated between 400 and 5600 mcd (millicandelas) at between 20mA. 20mA seems to be a standard current to quote the light output at, for most LEDs, not just white. However, Farnell also give lots of other data, including the maximum rated forward current, and the highest for any of the white LEDs is 30mA (made by Infineon and Multicomp). I don't think you should let them get warm :-) -- Pete Peter Turnbull Network Manager University of York

22 years, 9 months

Will someone delete me from this email list please as the commands do not work!!

by jamie＠rbattison.freeserve.co.uk

I want to remove myself from this list as i no longer have an interest in this subject. The commands on the website do not work so can the list owner please remove or can someone give me some idea of how to do it. cheers _______________________________________________________________________ Never pay another Internet phone bill! Freeserve AnyTime, for all the Internet access you want, day and night, only ?12.99 per month. Sign-up at http://www.freeserve.com/time/anytime

22 years, 9 months

RSTS/E on a PDP 11/34?

by mcguire＠neurotica.com

On December 26, Vintage Computer Festival wrote: > This may be a dumb question but... > > Will RSTS/E (specifically) RSTS/E-V7.0/07 run on a PDP 11/34? Dunno if this will be useful, but I ran RSTS/E v9.4 on a PDP11/34a for a long time.. -Dave -- Dave McGuire St. Petersburg, FL "Less talk. More synthohol." --Lt. Worf

22 years, 9 months

PAL introduction (was MITS 2SIO serial chip)

by pcw＠mesanet.com

The PAL was introduced in 1978, Other types of programmable logic devices were available earlier, (FPLA's for example) Here is a quote from one of the PAL's inventors (Andy Chan -- now at QuickLogic) "MMI's PAL was designed to overcome the problems associated with FPLA that made it difficult for end users. A proprietary programmer was necessary and a cumbersome inputting process (creating the design in Boolean equations, translating them into a bitmap and typing that into a machine that generated a paper tape for the programmer to read) meant that if the design didn't work, it was impossible to know at what step something went awry. Our PAL was faster and used less power, but the main improvement was in its ease of use, Chan said, noting that the first PAL chip was introduced in 1978." PCW

22 years, 9 months

PDP8/A memory problems, what to do?

by pete＠dunnington.u-net.com

On Dec 26, 12:08, Ethan Dicks wrote: > --- Gunther Schadow <gunther(a)aurora.regenstrief.org> wrote: > Good idea. I have a couple of quick routines I use as a basic > check-out, once I know I can read and write from/to field 0 > reliably - one is an inchworm for blinkenlights (or a counter > for the -8/a) I do that too. I also have a couple of very short toggle-in programs for the console serial line, one of which echos what you type. The last item I have that might be useful is a uploader that sends files, either plain or papertape images, to the RIM or BIN loaders -- it's on Kevin McQuiggin's page at http://highgate.comm.sfu.ca/pdp8/software/new-send.c > > The third 16k board > > plays the high fields 4 to 7, but it has a systematic > > error masking out bits 6 and 7. > Well... I doubt the core planes are bad, but I suppose it's possible. > I would suspect the bus buffers first, then, depending on the exact nature > of the problem there are failure modes of the inhibit drivers that could > whack your bits as they pass through a memory read cycle, but that's > not horribly likely. > > The trick is to sit there with the schematics and generate write cycles > and read cycles through the front panel as your trace the flow of bits > through the memory. I'd agree with that. It's more likely a logic problem than a core mat problem. > It's not cool like core, but did anyone ever come up with a modern > battery-backed-up SRAM board? I'm thinking of discussions of a few > years ago and talk about a quad-width OMNIBUS board w/2x62256 SRAMs. > Cheap to make (not counting a 1 sq. ft PCB), but compared to what we > used to pay for RAM...) and made with modern components. It may have > all been discussion without even a schematic generated, but I had to > ask. Yes, I've got one. It even has a connector to link to an interface in a PC, so you can squirt (or suck) data in (or out) directly. -- Pete Peter Turnbull Network Manager University of York

22 years, 9 months

PDP8/A memory problems, what to do?

by pete＠dunnington.u-net.com

On Dec 26, 14:20, Gunther Schadow wrote: > My first PDP-8 program is a memory test, and I was glad I > did it because I found a problem. My test goes through all > memory fields and writes into each cell its address in the > field. Then it reads that address out of each field again > and so finds problems. Good idea. I meant to mention in my followup to Ethan, that the diagnostics are also available, at http://pdp-8.org/papertape/ and the corresponding documentation is available at http://www.pdp8.net/query_docs/query_all.html The papertape images have headers, and the way the BIN loader works, you need to strip the ASCII header but leave at least part of the top-bit-set leader part at beginning and end. The "send" program I mentioned will take care of that. -- Pete Peter Turnbull Network Manager University of York

22 years, 9 months

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test-drb December 2001