test-drb June 2010

test-drb@ccmp.vtda.org

167 participants
232 discussions

Reading NorthStar Horizon hard sector disks on PC

by marvin＠west.net

> From: "Chuck Guzis" <cclist at sydex.com> > Not all Northstar diskettes are HS. One of the models (Advantage?) > isn't--and it's that format that the Microsolutions MatchPoint will > read, not the others. It's been too long since I've seen the darned > things... I think the machine you are thinking of might be the N* Dimension. The Advantage still uses 10-sector floppies. I've never seen the Dimension but vintagemicros on Ebay was selling one a while back and had a picture of it. Apparently it was MS-DOS compatible.

13 years, 10 months

PLATO@50 Conference

by legalize＠xmission.com

I've finally finished my article on the PLATO at 50 Conference: <http://legalizeadulthood.wordpress.com/2010/06/28/plato50-conference/> Please feel free to post comments/corrections on the blog. -- "The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download <http://legalizeadulthood.wordpress.com/the-direct3d-graphics-pipeline/> Legalize Adulthood! <http://legalizeadulthood.wordpress.com>

13 years, 10 months

yet another pdp-11 in fgpa

by w.f.j.mueller＠gsi.de

RodSmallwood" <rodsmallwood at btconnect.com> wrote: > How difficult would it be to extend one of these FGPA PDP-11's to be put > on a quad DEC board and be a plug in replacement for say an 11/93 or > 11/94 CPU. (M8981-AA OR 11/91-BA)? > > Rod Hi Rod, possible and feasible, but requires three tasks to be addressed: 1. an adapter board is needed to connect the FPGA development boards (holding the FPGA and memory) to the UNIBUS or QBUS. Main active part of this adapter board are the bus transceiver for UNIBUS or QBUS. 2. The UNIBUS or QBUS bus interface logic can be added to the FPGA. Given that the system clock period is small compared to typical times of these buses it is quite simple and straight forward to implement such a bus interface. 3. the current w11a implementation doesn't support bus masters on the I/O bus. DMA transfers from disk/tape devices are currently emulated. Next versions of the FPGA implementation however will add this functionality. But keep in mind: the current FPGA implementation isn't tremendously faster than a J11. Walter

13 years, 10 months

I'm thinking of buying a Falcon (time for an intervention)

by chrism3667＠yahoo.com

everyone gather round. No hard woods, only wiffle ball bats :) anyone own/used to own 1? In the rare event someone has one or more toasted units, and willing to part with them, I'm interested. There's more then one way to skin a cat (PERISH THE THOUGHT!).

13 years, 10 months

OT Konica Magicolor 2550 laser printer

by chrise＠pobox.com

I'm off topic but I know there are a lot of laser printer enthusiests here and hopefully someone that has been digilent about the firmware for this printer... not to mention people who like fixing things. Has anyone possibly kept older firmware versions for this printer around? I have a Magicolor 2550 that I have been running for several years. It always had a problem where it would fall off my network and I would have to power cycle it to recover. Didn't matter if DHCP or static IP was used... the ethernet would just go dead. A few months ago, I decided to "fix" this and went looking for a firmware upgrade. My firmware was orginal and there was a newer one, many revisions advanced. So, I reflashed the printer. This fixed the network problem however in trade, I got two new worse problems. Now, the image on the paper is slightly rotated... about 5 degrees so that it is no longer square to the paper. Additionally, the front panel keypad no longer functions and if you press any key, the printer enters into a loop, printing a menu page and you have to power cycle it to recover. Nice. I absolutely put in the correct firmware for this printer model so Konica apparently has some issues. I've gotten no response from Konica support and so I am looking for someone who may have archived older versions of firmware so that I can revert the thing to something less hostile. It was otherwise a really nice color laser printer and I _should_ have just lived with the network problem. Again, it's a Magicolor 2550EN. Not the "DN" model which does use a different firmware image. Thanks and I appreciate off-topic bandwidth. Chris -- Chris Elmquist

13 years, 10 months

yet another pdp-11 in fgpa

by tshoppa＠wmata.com

"Walter F.J. Mueller" <w.f.j.mueller at gsi.de> wrote: >> Johnny Billquist <bqt at softjar.se> wrote: >> > I wasn't aware that any prototypes ever were produced and came as >> > far as being functional. I thought it was just paper work that >> > had bee done. >> >> The 11/74 wasn't marketed, as pointed out in this thread, but a >> few systems were build by DEC. A picture of such 11/74 system >> was made available by Tim Shoppa, see >> >> http://www.trailing-edge.com/~shoppa/1174Xopen.jpg >> >> You'll nicely see the four CPUs. > Yes, I know of these systems. However, that is not an 11/74 on that > picture, but an 11/70mP. There is a difference... > As pointed out, the 11/70mP was marketed as an 11/74, but it's a > different CPU. > The easiest way to see that this is a picture of an 11/70mP is by > looking at the lower rotary switch, which only have four positions, and > not eight (which the 11/74 have). So no CIS on this machine. > The only 11/74 picture I've seen so far is the silk screen panel picture > posted a few days ago. Unfortunately I've already forgotten the name > (I'm lousy with names, sorry) of the person who posted it, and who also > worked on the 11/74 CIS microcode. > The machine on that picture is probably CASTOR:: by the way. The people who work with/maintain CASTOR:: call it a 11/74, FWIW. They never used the term "11/70mP" in front of me for sure. I would occasionally elicit comments about multiprocessing on 73's or 93's but it always came back to "our 11/74 does it THIS WAY" because that was the working example. I'm not saying that "11/70mP" is wrong, indeed it's used in some of the drawings and memos to describe what was commonly called the 11/74. CIS was real important to some DECcies circa late 70's for some Cobol requirement but coming from the real-time side none of us ever cared. We'd just run across machines that had this unneeded option. Tim.

13 years, 10 months

Ebay ISA NI AT-GPIB/TNT+. IEEE 488.2 (Analyzer), HPDrive compat?

by rdbrown＠pacific.net.au

Item number:300434169483 (9 boards @ USD10 + postage each) AT-GPIB/TNT+. IEEE 488.2 (ISA) Single-Board GPIB Interface and Analyzer I think the analyzer software that runs on Windows 95/98 and ME is bundled with the 1.70 version driver that may be available by request (from the 2nd URL) http://joule.ni.com/nidu/cds/view/p/id/532/lang/en http://www.ni.com/support/gpib/drivers/ I have run a similar card in a Compaq DeskPro 6500? P3 PCI machine with a legacy ISA slot (captured an HP150 boot sequence). As I read it the HPDrive software will run on Window 95/98, ME with this board. See the HPDrive site. http://www.hp9845.net/9845/projects/hpdrive/

13 years, 10 months

(OT) Laserjet III laser scanner module

by classiccmp＠philpem.me.uk

(... sending this from the correct FROM address would help...) Hi guys, I've got a Laserjet III laser scanner module kicking around in my junkbox, harvested from an utterly screwed LJ3. It has a fibre-optic light pipe on one side, which connects to a photosensor on the motherboard. Does anyone know what the frequency or period of the photocell signal is? That is to say, how long does it take for the scanner to make one complete pass from "horizontal blank" to the right margin -- in other words, the time from the leading edge of one photocell pulse to the next? I'm toying with the idea of repurposing the scanner module for another project (using a BluRay laser diode to print directly onto photographic paper then process using a 3-bath B&W process), and I'd like to figure out (in advance!) what the requirements will be placed on the paper drive system (among other things!) Thanks, -- Phil. classiccmp at philpem.me.uk http://www.philpem.me.uk/

13 years, 10 months

yet another pdp-11 in fgpa

by bqt＠softjar.se

"Walter F.J. Mueller" <w.f.j.mueller at gsi.de> wrote: > Johnny Billquist <bqt at softjar.se> wrote: > > I wasn't aware that any prototypes ever were produced and came as > > far as being functional. I thought it was just paper work that > > had bee done. > > The 11/74 wasn't marketed, as pointed out in this thread, but a > few systems were build by DEC. A picture of such 11/74 system > was made available by Tim Shoppa, see > > http://www.trailing-edge.com/~shoppa/1174Xopen.jpg > > You'll nicely see the four CPUs. Yes, I know of these systems. However, that is not an 11/74 on that picture, but an 11/70mP. There is a difference... As pointed out, the 11/70mP was marketed as an 11/74, but it's a different CPU. The easiest way to see that this is a picture of an 11/70mP is by looking at the lower rotary switch, which only have four positions, and not eight (which the 11/74 have). So no CIS on this machine. The only 11/74 picture I've seen so far is the silk screen panel picture posted a few days ago. Unfortunately I've already forgotten the name (I'm lousy with names, sorry) of the person who posted it, and who also worked on the 11/74 CIS microcode. The machine on that picture is probably CASTOR:: by the way. > arcarlini at iee.org wrote: > > I've read somewhere that it [PDP-11/74] was full of flat ribbon > > cables and would have been a beast to maintain. > > Well, you see on the picture that there was quite a bit of > flat ribbon cables :). Yes, when you run multiple CPU configurations, you do get many flat cables. However, if you were to run the 11/74 in a single CPU configuration, it would not have had more flat cables than an 11/70. So it seems strange if that would have been the reason for cancelling it. On the other hand, I think that CIS never was popular, or in any demand, for the PDP-11, so if that (and multiprocess capability) was the only things the 11/74 brought to the table to differ it from tne 11/70, then I can understand why they would cancel it if they had problems with the multiprocessor part. > The 'PDP 11/70 Multiprocessor Technical Manual (Preliminary Version)' > is on bitsavers, see > > http://www.bitsavers.org/pdf/dec/pdp11/1174/EK-70MP-TM_PRE_1170mp_Prelim_Te… > > and gives you a feeling of the modules and interconnects. Yes. And all evidence I ever see is that the only systems DEC actually did get working was the 11/70mP. That they actually got the 11/74 (CPU) beyond paperwork was what was news to me. > Johnny Billquist <bqt at softjar.se> wrote > > You do know that the J11 is already designed for mP usage, except that > > DECs testing of that was even more secret than the 11/74? > > Sure, the mP instructions WRTLCK and the TSTSET of the J11 are > documented, and allow cleaner way to implement spin locks than > the 'asrb hack' of the 11/74. In a future version of the w11a I'll > probably also implement the instructions supported by 11/34 and > J11 and make the 'processor profile' selectable at start time, much > like in the simh simulator. That would be nice. While RSX don't use it, you could use it for Unix, or other systems. The J11 also have the cache bypass bit in the PDR, btw. What instructions are you thinking about when you say 11/34 btw? > > But FPP is among the most important things in there as well, I'd say. > > Lots of software who won't be happy without it. > > That's true from a performance point of view. However > - you can run RSX and Fortran without FPP (did this 30 years ago > when the FPP broke on the 11/45 I was working with...). True. But you cannot run almost anything else. I don't think I've seen any other language that do not require the FPP. > - you can run 2.11BSD without FPP (I'm doing that each time I > boot 2.11BSD). Yes, that was fixed recently, right? > So a FPP is very good to have, but not my highest priority. Also, > it's quite a project to design, implement and verify it, with the > verification, as usual, being the most time consuming part. True. > > By the way. You don't have to worry about cache coherency. The > > PDP-11/74 do not do that. Cache coherency is managed by software > > on the PDP-11 (well, in RSX, since that's the only system that > > supports the hardware). In short, the real hardware do not implement > > any sort of cache coherency in hardware. > > I know, but I'll go for a cache with full cache coherency. That will > make it a lot easier to try a MP hack for 2.11BSD. And RSX, if I ever > get to it, will not mind. True. Definitely will not break anything. But it will make your life more complicated. :-) > Johnny Billquist <bqt at softjar.se> wrote: > > Good thinking. > > But I'm surprised by some numbers here. The J11 at 20 MHz is > > only slightly faster than an 11/70. In fact, if you can throw > > the 11/70 into running all from cache, it might even be slightly > > faster than an 11/9x. > > Or so I seem to remember from looking at the numbers back when > > I last was digging into this. > > > > Maybe I'm mixing some numbers up here... What I do remember for > > sure is that the 11/9x machines run at 20 MHz, and that they are > > not more than maybe 1.2 times the speed of an 11/70 in general. > > oops, you are right, I was mixing numbers here and forgot about > a factor of four. Here the revised arguments: > > See http://www.village.org/pdp11/faq.pages/prfmnc.html , there > is a table comparing 11/70 with various J11 systems: > > 11/23 11/53 11/73 11/83 11/93 > ----- ----- ----- ----- ----- > CPU F-11 J-11 J-11 J-11 J-11 > Microcycle(ns) 300 267 267 222 222 > Clock (MHz) ? 15 15 18 18 > Performance 0.2 0.5 0.7 1.2 1.4 > (11/70 = 1) > Cache no no yes yes no > Floating-Pt opt no no yes yes > Coprocessor > > My mistake was to forget that the J11 needs 4 clock cycles per > microcycle (MC), that's why 18 MHz clock leads to 222 ns MC period. > > In the end the J11 (222ns MC) is faster than the 11/70 (150 ns MC) > because it has a better micro architecture (three stage pipeline > vs. instruction prefetch only). The J11 is roughly a factor two > better compared to 11/70 in terms of MC efficiency. Hmm, I seem to remember checking numbers a while ago and came to the conclusion that if the 11/70 would have all memory as cache, it would outperform the J11. Atleast at 18MHz, maybe also 20MHz. (Btw, that table is slightly wrong, as the 11/9x eventually made it to 20MHz). I have a processor handbook which gives instruction speeds of 11/70 instructions with cache hits and without, which tells you how fast the machine would be if you were all cache. The 11/70 suffers because memory is so slow. Johnny

13 years, 10 months

yet another pdp-11 in fgpa

by w.f.j.mueller＠gsi.de

Johnny Billquist <bqt at softjar.se> wrote: >>.. >> "Walter F.J. Mueller" <w.f.j.mueller at gsi.de> wrote: >> At some later time maybe I'll try a really fast design, with separate >> instruction and data caches and significantly more parallelism than >> the J11 had. > Hmm. I wonder if that might cause headaches? There might be code out > there that require your i-cache and d-cache to be consistent with each > other. sure, there is self modifying code. The maindec zkdjb2 for example has a sequence like mov #000240,(pc) jmp (r1) and tests that the 'nop' was executed and not the 'jmp'. However, the cache, even separate i-d, is only one aspect, main point is to get all the different 'write-after-read' hazards in the pipeline under control. That's why I stayed with a simple 'prefetch-only' 11/70-like implementation in the first round. Even in that case one has to be careful and suppress for example the prefetch when the destination is pc. Otherwise a 'clr pc',often found at the end of primary bootstraps, will not do a 'jmp @#000000' but execute the opcode after the 'clr pc'. Walter

13 years, 10 months

← Newer
1
2
3
4
5
6
7
8
9
...
24
Older →

Jump to page:

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 June 2010