Hi gang.
First off, let me say that this is my first post to this list. I have
followed some of the classic computing USENET lists but find the SPAM
content to be too high anymore. I was only recently introduced to the
classic computing website but I have really enjoyed lurking and reading
about the many machines you are all working on. It's really been a joy
to follow this list. My thanks to the gentleman I met at Dayton who
pointed me here. I don't remember your name, but you were in the upper
lot and had some DECpacks sitting near your pickup. They attracted me
like a moth to a flame!
Anyways, I've always enjoyed classic computers and I have a particular
interest in DEC PDP-11s. I cut my teeth on RSTS/E running on a
PDP-11/34a and while my laptop runs rings around my 11/34a, I find the
visceral pleasures of blinking lights and clacking drive heads totally
lacking in the new machines. I'm a ham operator who also appreciates
the warm glow of tube equipment, but that's another story...
The point of this post is that I have in my posession the following books:
The AmigaDOS Manual (Commodore-Amiga, Inc.)
Advanced Amiga BASIC (Tom R Halfhill and Charles Brannon)
Mastering AmigaDOS (Jeffrey Stanton and Dan Pinal)
and the best of the lot:
An Amiga binder with the owner's manuals:
Introduction to Amiga
Flow ... Idea Processor for the Amiga Computer
Amiga Basic
I'd like to send them to someone who would appreciate them. Any takers?
Barry
I picked up a pile of 8" floppy disks recent and I finally got around to
looking them today and found some distribution disks for something. Some of
the GenRad circuit board test stations used DEC computers as controllers
and these disk came from GenRad. The box says "GRnet Release 3.0.2 (for
RSX-11M 3.2)". I'm not sure if these are distribution disks for RSX-11M or
only for some kind of software that runs under RSX-11M. Anyone know
anything about this? There are five disks in the set and they're still new
and unused and sealed in plastic.
Joe
I sent my last reply to that other thread before reading Jay's request
to kill the thread. My bad.
James
--
www.blackcube.org The Texas State Home for Wayward and Orphaned Computers
> I almost hate to ask the obvious, but does something have specifications
> for the SASI protocol? That would go a long way to answering some of
> the questions.
Try http://www.bitsavers.org/pdf/shugart as there are controllers in there.
Also some information in the '1984 Storage Management Products
Handbook' Western Digital. Board WD1002-SMD.
Regards,
Garry
Tim Shoppa wrote:
> The most frustration comes when I decide to "look back" and see how
> nothing that I did made any difference in the end. Oh well, it was
> fun at the time.
Tim,
As someone who worked on DEC-10's, for DEC (on FORTRAN-10/20), then
using DEC-20's, your work on helping to save PDP-10 software alone
qualifies you for sainthood in my book (and I imagine many others' as
well)!
I have my own little corner of the 20th century I've tried to save
(www.gull-wing.net). Its it's own reward... Well, that at the e-mails
I get on occasion saying someone thinks the web site is awsome...
(In other words, I think your work is awsome!)
phil
The 2147 us a 4kx1 part with speeds ranging from 70ns (in 1982)
to as fast as 45ns. In later years they got down to 25ns.
In the time frame they appeared in S100 boards ram was either
slow (greater than 250ns) or fast (sud 70ns) with the costs
to go with it. To build a 200ns board you needed ram faster
than 200ns to allow for propagation delays in the interface
and decode logic. So the 2147 was a choice.
I may add they ate current like mad when selected around 160ma
@5v and in standby it dropped to 20ma so board layout was had
to be very good.
Allison
>
>Subject: RE: S100 RAM replacements - 2147's on Godbout boards
> From: "Richard A. Cini" <rcini at optonline.net>
> Date: Sat, 16 Jul 2005 20:26:28 -0400
> To: "'General Discussion: On-Topic and Off-Topic Posts'" <cctalk at classiccmp.org>
>
>JDR listed it as 55nS which I thought was incredibly fast for an S100
>system where 200nS was more common. It is indeed a 4kx1 chip according
>to the product listing.
>
>Rich
>
>-----Original Message-----
>From: cctalk-bounces at classiccmp.org
>[mailto:cctalk-bounces at classiccmp.org] On Behalf Of Barry Watzman
>Sent: Saturday, July 16, 2005 1:19 PM
>To: cctech at classiccmp.org
>Subject: S100 RAM replacements - 2147's on Godbout boards
>
>
>
>The 2147 was a mainframe cache static memory chip. It is extremely
>fast, I think in the 35 nSec range, and uses less power than most of the
>static memory chips more commonly used in S-100 systems, although being
>a static memory chip, it is not "low power" by any stretch of the
>imagination.
>
>My recollection is that it's a 4kx1 chip with the same pinout as the TI
>4044 and almost all of the other 4kx1 static memory chips, and that you
>can actually substitute or mix 4044's and 2147's (the 4044's are nothing
>like as fast, but in a 2 to 4 MHz S-100 system, you only need 150 to 250
>nSec). However, please check this out, as it's possible that the 2147
>was 1kx4 instead of 4kx1.
>
>I don't know why no one else used this chip, but it is a fantastic
>static memory chip.
>
>
The 2147 was a mainframe cache static memory chip. It is extremely fast, I
think in the 35 nSec range, and uses less power than most of the static
memory chips more commonly used in S-100 systems, although being a static
memory chip, it is not "low power" by any stretch of the imagination.
My recollection is that it's a 4kx1 chip with the same pinout as the TI 4044
and almost all of the other 4kx1 static memory chips, and that you can
actually substitute or mix 4044's and 2147's (the 4044's are nothing like as
fast, but in a 2 to 4 MHz S-100 system, you only need 150 to 250 nSec).
However, please check this out, as it's possible that the 2147 was 1kx4
instead of 4kx1.
I don't know why no one else used this chip, but it is a fantastic static
memory chip.
All:
I decided to run a memory test on some boards I have and I found a
bad chip. It's on a CompuPro RAM14 and the chip is a MM2147J. None of my
other 16k boards has this chip (VG boards; contain 2114s but the boards have
"BAD" labels on them so I've never plugged them in). The chip does not have
a speed marking that I can see and I don't have a copy of the RAM14 manual
although it might be similar to the Godbout EconoRam IV which uses the
40144/mm5257 chips.
Can anyone help me with a suitable cross for this chip...and a
source? My usual haunts don't show stock on this number.
Thanks.
Rich
Rich Cini
Collector of classic computers
Build Master for the Altair32 Emulation Project
Web site: http://highgate.comm.sfu.ca/~rcini/classiccmp/
/************************************************************/
When I was at J.D. Edwards (R.I.P.), Retrobox handled reselling the
company's old computers. They offered employees a "special price," but it
was hardly a deal.
>From what I know, Retrobox deals mainly with PC hardware from large
corporate accounts and resells it at a fairly high price.
Bob
<Original Message>
Date: Sat, 16 Jul 2005 01:23:39 -0500
From: Ethan Dicks <ethan.dicks at gmail.com>
Subject: Re: Newsbreak: NPR: -.retrobox.-
<snip>
1997?!? I'm really surprised to not have heard of them before now. I
checked on their website... I've been by their place dozens if not
hundreds of times in the past 7 years (not that I'd expect a large
sign saying "Turn Left for Old Computers".
I'd love to hear what people find, but, again, from their web pages,
it looked like they a) don't know much about non-PC equipment (look at
the Sun systems for sale), and b) think the stuff's made of solid
gold.
-ethan
<snip>
>
>Subject: FDC Gap Length?
> From: Dave Dunfield <dave04a at dunfield.com>
> Date: Sat, 16 Jul 2005 13:55:05 -0400
> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
>
>Hi Guys,
>
>I've been doing a bit more work on my replacement for TeleDisk, and I have
>it working quite nicely, however I do have one area that I could some help
>with...
>
>The 765 FDC requires two "Gap Length" values, one for formatting (total gap
>between sectors), and one for writing... I have been unable to find any
>information about calculating these values from arbitrary sectors/track,
>encoding and transfer rate. All of the documents I have found simply give a
>table of suggested values for common disk formats, but give no hint as to
>how to calculate them for uncommon or arbritary formats. (for example, the
>fairly common 9x512 format is not included in the table).
>
>Currently, I am using the values from the table, and some "guesses" for
>values for some other formats which I have tried, however I do not know
>how to derive the correct value for these items. A couple hours on Google
>turned up numerous articals, ALL of which either:
> a) use a single fixed value
> b) use the NEC table
> c) call then "magic" numbers
> or
> d) say they can't provide more information on how to select GPL due to
> lack of information.
>
>With the 765, I cannot determine the gap length used on the original
>disk, so the best I can do is to try and determine a suitable gap length
>when formatting based on the # sectors, sector size, encoding method,
>transfer rate and drive type....
>
>Can anyone provide any clues?
>
>Regards,
>Dave
The total number of bytes, gaps plus data, must not exceed the total
number of possible byts on the media at nominal rotation speed.
When formatting the last gap is longer than the track so that you write
gap until you see index to fill out the track.
For reading there is a minimum number of bytes for the gap and if
memory serves 16 (decimal) is it for DD and 10 for SD. These are not
optimum for writing however. For writing you need to insure there are
enough gap bytes in a gap to assure the minimum needed for PLL data
seperators to aquire and track after the splice point. The splice
point is the location on media when after reading sector-n and
finding that sector n is next then switching to write. The result
is always a discontinuity in the mid gap area from switching in the
erase head and beginning the first gap byte written.
Is there a calculation, NO. Unless your formatting your own, then
it's use biggest gaps that allow sector data and a resonable end gap
on off speed drives. Most of the time you have to know how
that disk was formatted originally to arrive at the correct values.
Fortunatly there is a fair amount of wiggle room if you do not run
too close (too close is below) to minimums. A good example of that
is the RX50 (10sectors 512bytes on 5,25 floppy) as the 765A can
read it but barely (not really) formats that correctly, to format
that with non WD you need upD7265.
hope that helps some.
Allison
