Hello,
Finally got a tape for this thing and it is DOA -- doesn't seem to do
anything. The lower green LED on the tape drive flashes slow then fast.
Interesting thing though -- when I interrogated the SCSI buss, it came back
as a DEC RZ24L. thought you DEC fans might know what that is, and if it is
a proprietary model that I can't use on my Amiga.
Kind regards
--
Gary Hildebrand
ghldbrd(a)ccp.com
--- allisonp <allisonp(a)world.std.com> wrote:
> >[ Its the chip used in the Apple Lisa and Mac and LOTS of other devices. ]
>
> You sure of this?? It's not really friendly to the 68k buses.
>
> Allison
I'm sure. It's in the Mac from day one, in Sun workstations since at least
the Sun3 era (and still in one form or another in various sun4c boxes) and
in every 68K-based product Software Results made after the Unibus products
(the original boards used the COM5025 like the DEC DPV11? DUV11?)
I will admit that it is not friendly to the MC68K bus. We used one or two
dedicated PALs to handle the interfacing. Additionally, we had an 8Mhz CPU
(10Mhz for the VAXBI model), but back when the Z8530 was new, 4Mhz parts
were available and later some 6Mhz, but 8Mhz parts didn't come along until
way later, long after our designs were done. There's lots of notes in the
COMBOARD source code about not wacking on the Z8530 too fast. Eventually,
we developed a kind of serial driver to handle swabbing registers, but the
first products just used macros to always space out the time between telling
the Z8530 which internal register to select and reading/writing that register.
Personally, I think it's a cool chip, much cooler than the 8250/16450/16550
family. In addition to an async console for debugging, we pumped 3780, HASP
and SNA traffic over them up to 128Kbps (our fastest modem eliminator speed).
We only ever sold products for use at 56Kbps (64Kbps in Europe).
-ethan
=====
Even though my old e-mail address is no longer going to
vanish, please note my new public address: erd(a)iname.com
The original webpage address is still going away. The
permanent home is: http://penguincentral.com/
See http://ohio.voyager.net/ for details.
__________________________________________________
Do You Yahoo!?
Yahoo! Photos -- now, 100 FREE prints!
http://photos.yahoo.com
Need this for my emulator, and nobody can explain to me how it works, and
I can't find any documentation that's useful to me. Specifically, I need stuff
like "you shift left and then check the last bit" etc. etc. Basically, I have
a bunch of ones and zeroes and I have to know how to add/subtract/multiply/
divide with them.
-------
Daniel Seagraves wrote, in his classic style of leaving the body of the
message devoid of any any actual context as to what he's asking about and
requiring a reference to the Subject line:
>Subject: Can someome explain how arithmetic works?
>Need this for my emulator, and nobody can explain to me how it works, and
>I can't find any documentation that's useful to me. Specifically, I need stuff
>like "you shift left and then check the last bit" etc. etc. Basically, I have
>a bunch of ones and zeroes and I have to know how to add/subtract/multiply/
>divide with them.
A *very* popular book for introducing this subject to students these days is
_Computer Arithmetic: Algorithms and Hardware Designs_, by Behrooz
Parhami. It's a pedantic, general purpose introduction, with an emphasis
on conveying a true understanding of the subject through how the bits
are actually banged about.
An even more pedantic introduction is Donald Knuth's _The Art of Computer
Programming, Vol 1: Fundamental Algorithms_. It's probably not so good as a
introduction if you're really unfamiliar with the subject already,
but it's a true classic in the field, and anyone who has worked in the
field goes back to it every so often for some deep insight. For example,
I just browsed through it a couple days ago for some grokking of how negative
number base arithmetic works. Neat feature: no sign bit necessary!
Another good reference, if you've already got some experience with
computer architecture books and want to leverage this knowledge, is
the IEEE Tutorial titled simply _Computer Arithmetic_ and edited by
Earl E. Swartzlander. There's also Kai Hwang's _Computer
Arithmetic: Principles, Architecture, and Design_ and Israel
Koren's _Computer Arithmetic Algorithms_.
I suspect that you just want a cheat-sheet for a few specific applications,
in which case there's probably a Schaum's outline paperback that will get you
by but without conveying any real understanding about how it works or why
it works the way it does. I'm sure your local library has some similar
workbook-style textbooks.
Perhaps intermediate between the dumbed-down level of Schaum's Outlines
and the high-and-lofty ivory tower view of Knuth would be a good
numerical analysis text intended for scientists who have to learn
the basics of how computers do arithmetic, and how this differs from
traditional school-book arithmetic. _Numerical Recipes_ doesn't quite
fit the bill, but when I
was an undergrad I took several numerical analysis courses and all the
textbooks had good, but terse, introductions to computer arithmetic, both
fixed and floating-point. Again, I'm sure your local library has some
good books.
--
Tim Shoppa Email: shoppa(a)trailing-edge.com
Trailing Edge Technology WWW: http://www.trailing-edge.com/
7328 Bradley Blvd Voice: 301-767-5917
Bethesda, MD, USA 20817 Fax: 301-767-5927
----------
> From: Mike Cheponis <mac(a)Wireless.Com>
> To: classiccmp(a)classiccmp.org
> Subject: Re: Woz and his 6 chips...
> Date: Friday, June 02, 2000 12:14 AM
>
> Ladies & Gents, now I -gotta- know: What were those 6 chips, and is there
a
> schematic somewhere?
If you want to see a nice picture, see eBay auction 341188950 (ends June
3).
I took a photo of an ASCII art poster I have featuring the Golden Gate
bridge and an airplane flying over it:
http://www.siconic.com/crap/ascii_bridge.jpg
It's made of up roughly 7 x 8 squares of wide carriage printer paper and is
roughly 9 feet wide by 7 feet high.
It's yellowed with age because it had been hanging on the wall of the
person who originally printed it for I believe a couple decades or so.
Sellam International Man of Intrigue and Danger
-------------------------------------------------------------------------------
Looking for a six in a pile of nines...
Coming soon: VCF 4.0!
VCF East: Planning in Progress
See http://www.vintage.org for details!
On Jun 2, 15:23, John Foust wrote:
> I think this is on an RSX ASCII collection tape I got from
> someone or somewhere. In the "readme" FILENN.IDX, it's the
> largest file:
>
> FILE14.LST 12,405 * Golden Gate Bridge
>
> where 12,405 records translated to 1,659,857 bytes. I'd be
> glad to send a zipped version to anyone who wants it.
>
> By comparison, the popular Moon picture is 950,283 bytes, and
> the Einstein is 348,400 bytes.
I'd like copies of these, if you can make them available...
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
I'm looking for one of the original Cap'n Crunch cereal whistles that could
produce the 2600Hz tone. If you know the story of John Draper (a.k.a.
Cap'n Crunch) then you know what I'm talking about.
I'd also like to get a hold of the box the whistle came in. I'm also looking
for the October 1971 issue of Esquire magazine that featured the article
with John Draper talking about the "blue box".
If anyone has any idea where I might find these items, please e-mail me
directly at <sellam(a)vintage.org>.
Thanks!
Sellam International Man of Intrigue and Danger
-------------------------------------------------------------------------------
Looking for a six in a pile of nines...
Coming soon: VCF 4.0!
VCF East: Planning in Progress
See http://www.vintage.org for details!
Here's something I pondered the other day:
Why is AppleSoft BASIC called "AppleSoft" BASIC?
^^^^
Does this have something to do with the fact that Microsoft designed it?
I can't think offhand of any other Apple software product that fell
under the designation of "AppleSoft".
Something tells me Eric may know this.
Sellam International Man of Intrigue and Danger
-------------------------------------------------------------------------------
Looking for a six in a pile of nines...
Coming soon: VCF 4.0!
VCF East: Planning in Progress
See http://www.vintage.org for details!
Regarding recording data on analog 35mm film, below is a recent
excerpt from a microscopy mailing list, where people were
discussing the use of film to record detail, as opposed to
CCD imaging techniques:
> To begin to answer Jeremy's question directly, we need to know
> how much detail a Technical Pan negative can record. The figures
> depend on processing technique and the test object luminance and
> contrast, but the modulation transfer function figures published by
> Kodak indicate that a spatial frequency in excess of 200 cycles per
> mm is easily recordable. For a test object with contrast 100:1 they
> quote 320 line pairs per mm. The CCD pixel spacing required to
> achieve this feat would be 640 pixels per mm. That equates to a
> requirement for 15360 x 23040 pixels to match the resolving power
> of a 24x36mm Technical Pan exposure. That's 0.35 Giga pixels in
> round numbers.
- John
