On Sep 29 2004, 0:10, Vintage Computer Festival wrote:
> On Wed, 29 Sep 2004, Pete Turnbull wrote:
>
> > [1] They're not paired as 1+2, 3+4, etc either. The first pair is
the
> > centre pins, the second pair is the two pins either side of centre,
and
> > so on, working outwards.
>
> The third and fourth pairs would not be "so on". They'd be the pairs
on
> either side of the center, since Orange+White/Orange and
Brown+White/Brown
> are not split.
Er, no, in a USOC-wired RJ45 pair 1 is pins 4+5, pair 2 is pins 3+6,
pair 3 is pins 2+7, pair 4 is pins 1+8. You're thinking of TIA 568,
where pair 1 is 4+5 (blue), pair 2 is 3+6 (green), pair 3 is 1+2
(orange) abnd pair 4 is 7+8 (brown), as I wrote above the bit you
quoted.
--
Pete Peter Turnbull
Network Manager
University of York
IIRC from Bob's speech at VCFe2.0, he indicated that simulation speed is
effectively unregulated, because why would you want to waste the benefits of
a speedy host machine. However, I could imagine that with certain hardware
simulations, cycle-by-cycle emulation might be required.
On my Altair32 emulator, I have it set to run at the prototypical 2MHz speed
(8080A). But, I can unthrottle it and let it run at full speed, which on my
Pentium 4/2.8GHz would result in an 8080 running at about 80MHz (+/-). This
is accomplished by managing the number of prototypical CPU cycles executed
per 10ms timeslice.
Rich
-----Original Message-----
From: cctalk-bounces(a)classiccmp.org
[mailto:cctalk-bounces@classiccmp.org]On Behalf Of Tom Jennings
Sent: Monday, September 27, 2004 3:24 PM
To: General Discussion: On-Topic Posts Only
Subject: simh simulation speed
I haven't had a chance to get back and debug, but is it true that simh
does NOT simulate the target machine's execution speed? I wrote a simple
'sum all words in track N' program for the LGP and it completed as soon
as I hit return! It should have taken many seconds... I did RTFM, so no
reference to it, but I haven't had time to go look at the source. Got
lazy and decided to post instead of research (typical, huh :-)
spc(a)conman.org (Sean 'Captain Napalm' Conner) wrote:
> Okay, figured out why my code didn't work, and it's not due to writing to
> the wrong location (although I suspect that still is a problem) but that
> under Unix the code pages are marked read-only so of course it core dumped.
You do know about -N option to ld, right? That would make an OMAGIC
executable whose code is not protected.
MS
Can anyone use an old Marconi Instruments test equipment catalog? I have
an old edition here (NA7) that needs to go away. Inside are the usual
picures and descriptions of the gear (much like the big HP catalogs). Of
interest to those on this list are the ATE equipments - there are some
nice shots and data for their PDP-11 (the original) based test sets.
William Donzelli
aw288(a)osfn.org
I just finished putting some stuff on E-bay that this group might be
interested in including some single height DEC FLIP CHIP wirewrap cards, a
HP-12C calculator, a box and manual for the HP-11C calculator and a bunch
of ROM and RAM cartridges for the Tektronix 83x Communications Analyzers.
Those of you that are making your own cartridges for the Tektronix 124x
Logic Analyzers will be interested to know that these cartridges will also
fit the 124x LA if you trim the locator keys. See
<http://www.classiccmp.org/hp/tek-roms/case-keys.jpg>. I will be adding
some core memory boards as soon as I have a chance (probably a couple of
days).
<http://search.ebay.com/_W0QQgotopageZ1QQsassZrigdonjQQsosortorderZ1QQsosort
propertyZ1>
Joe
(not sold by me & cross-posted from another list)
"The entire Freeman PC Museum is offered for sale. David Freeman, founder of
ACP Superstore, has been collecting computers since 1976. As a pioneer in
computer retailing Mr. Freeman started early collecting. This collection
represents almost 30 years of collecting. To date over 280 computers have
been place online at www.thepcmuseum.net. There are approximately 600
computers, calculators, printers, video game consoles in the collection. Not
all of the computers have been placed on the website as of yet, but all are
included in this sale. Everything is included. Many items in this collection
are irreplaceable and no longer available. This collection includes
countless software titles, manuals, books, magazines and other computer
memorabiia. You could truly display a PC Museum in your place of business
with this collection...."
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=5125710949
>From: "Ron Hudson" <ron.hudson(a)sbcglobal.net>
>
>I had, at one point, sat down and tried to devise a JK flipflop out of
>relays..
>
>I can do a latch... where (in) pulls in the relay and a NO contact
>connects
>v+ to keep the relay in.. but everything I tried just vibrated... :^\
>
>In a relay computer wouldn't one need flipflops for memory?
>
I thought I'd take on the challenge. Doing a JK with relays.
First, define the clocking and, for Sellam, the state of the contacts.
I will define relays as numbers and there contacts as O for normally
open and C for normally closed. As an example R1C will be one of the
normally closed contacts. If this name is used multiple times, it
may indicate more than one set of contacts, depending on the optimization
used. There will be 4 clocks. It will look as:
One cycle of clock.
P0 C O C C C C ( Hold clock for R1 )
P1 O C C O O O ( evaluate clock for R1 )
P2 C C C C O C ( Hold clock for R2 )
P3 O O O O C C ( evaluate clock for R2 )
O means open contact at that time and C means closed during that time.
The JK flop is composed of two relays, R1 and R2. R2 contacts correspond
to the Q and Q* outputs( R2O and R2C ). R1 or R2 by itself would be
the coil. I also show the complete path from rail to return, even
if it is duplicated at some points. JO and KO are normally open
contacts of some other relay that when activated is the logical
signal corresponding to J and K.
Wiring:
Rail to R1O to P0 to R1 to return
Rail to R2O to KC to JC to P1 to R1 to return
Rail to JC to KO to P1 to R1 to return
Rail to R2C to JO to KO to P1 to R1 to return
Rail to R2O to P2 to R2 to return
Rail to R1O to P3 to R2 to return
I would not use a JK flop for a memory array, even if I was using
normal relays for the memory. The are too wasteful of contacts
and coils. There is some optimization that could be done with
diodes as well.
One can generate the clocks with relays or some kind of distributor,
similar to what is used on a teletype and a variable speed motor.
If done with relays, one would need some way to control the speed.
It might make sense to invert the signal between the two relays
so that regardless of the state, only one relay, on averagel would
be on at a time.
Dwight
>From: "Tom Peters" <tpeters(a)mixcom.com>
>
>I use a lot of self-modifying code: Perl scripts that generate HTML code!
>
>Maybe that doesn't count...
>
Hi Tom
Only counts if it then calls the HTML is generates.
Dwight
>From: "Vintage Computer Festival" <vcf(a)siconic.com>
>
>On Mon, 27 Sep 2004, Dwight K. Elvey wrote:
>
>> In my logic, 'A' would indicated the normally opened contact
>> an 'a' would be the normally closed contact for relay A.
>> I'll use + to indicate OR and . to indicate AND.
>
>You already lost me. You may as well have used ! and $ instead of A and
>a.
>
>:)
>
>P.S. C programming convention (which most people would relate to
>immediately) says that next time you should use & for AND and | for OR.
>
>--
Hi
I'm sorry, people doing logic have been using + and . a
lot longer than C has been using & and |. I specifically stated
what I would use. Look at most any pre-C math book and
you'll most likely see the + and . used for OR and AND.
These are just symbols until one applies meaning to them. I
don't see the issue. One should be able to adapt to different
conventions because that is the way things will be represented
>from different sources. I adapt and I hope others learn to
do it as well.
I don't see the issue with using upper and lower case to
indicate normally close or normally open? What difference
does it make how one represents it?
Dwight