I'm trying my darndest not to get too involved in this thread, even though
I started it, but I need to set the record straight: The URLs I sent
weren't from ebay, they were from Haggle Online. An online auction that is
totally free to buyers and sellers, unlike ebay, that charges a fee to
sellers. Not that it really matters, since online auctions seem to be the
new "great satan" on this list. I would like to point out though that if
you don't know the true value of an item, why not let the public decide?
What's wrong with making a little bit of money off a hobby? I know this
probably isn't over, but I'll try to stay out of it, regardless.
At 07:15 PM 6/10/98 -0700, Sam Ismail wrote:
>I and others have said in the past that there's no wrong reason for
>wanting to collect computers, but this craze I see going on at eBay is in
>the very least stupid.
-
- john higginbotham ____________________________
- webmaster www.pntprinting.com -
- limbo limbo.netpath.net -
<One of the smallest multitasking systems I've seen was the I/O processor
<on the PERQ 2's. It was a Z80 with 4K ROM and 16K RAM, but said ROM
<contained essentially a cooperatively multitasking kernel. Some tasks
<were in ROM, others were loaded into RAM. OK, so the user never realised
<what was going on, but that doesn't alter the fact that it was there :-)
The smallest I've seen run on 8080 and fits in some 100 or so bytes. It
was published in Kilobaud April 1978 page 102 and yes it was real.
To multitask on most anything all you need is an interrupt and save the
context of the current task and start some new task... the order, where
the tasks are and memory allocation can be somewhat tricky but, for
small tasks its pretty trivial. I've done it in 8048 MCUs where the
resources were 64byts of ram and 1k of rom and the tasks were keyscan,
display, serial IO and code conversion. The timer provided the
interrupt.
Allison
bit hard getting a mac into a pc case though, remember that macs have all
the connectors on board,
desie
-----Original Message-----
From: Sam Ismail <dastar(a)wco.com>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Monday, June 08, 1998 5:41
Subject: Re: Early Mac Clones
>On Sun, 7 Jun 1998, Tom Owad wrote:
>
>> What edition do you have? My 2nd edition book says a listing of clones
>> is given in edition 1, as oppose to just saying they exist. I'd love to
>> get a list of old Mac clones.
>
>I made a timely find today of the first edition of _Build Your Own
>Macintosh and Save a Bundle_. In Chapter 2 it has a price comparison
>between the clone "Cat" Mac and the real Mac. The computers it lists are:
>
>Cat Mac SE
>Cat Mac SE 30
>Cat Mac II
>Cat Mac IIfx
>Cat Mac IIcx
>Cat Mac IIci
>
>It will indeed be interesting if I ever find one of these homebrew clones
>(For the curious, the book basically tells you to buy Mac motherboards and
>parts from third-party suppliers and stick them in a PC case. That's it.)
>They would be hard to spot since I don't even give a first look to PC
>clone boxes. There's not really anything special about them anyway, other
>than the fact that it is novel.
>
>Sam Alternate e-mail:
dastar(a)siconic.com
>---------------------------------------------------------------------------
----
>Ever onward.
>
> September 26 & 27...Vintage Computer Festival 2
> See http://www.siconic.com/vcf for details!
> [Last web page update: 05/30/98]
>
>> The MC68010 is the heart of my favorite computer ever, the AT&T Unix PC
>> (built by Convergent Technologies). I've got three, two work fine, one
>> is for parts. _Still_ the prettiest machines in my collection.
Do you mean the NCR Tower series? Or was this some other offering by
AT&T? I seem to remember that the old Tower 400's had 68010's - I've
still got a few boards somewhere for one (system board was about 1 metre
long and half a metre high!). I've got a complete Tower 700 with a 68030
as main CPU, and performance still rates really highly even these
days...)
Jules
On Jun 10, 14:56, Max Eskin wrote:
> How do UNIX files work? Is there a header of some sort?
Not really. Certainly not consistently across all file types. Often
command scripts have a comment at the top, and some versions of unix (eg,
Irix) embed a "tag" number into executables so they can distinguish
individual programs/versions quickly, but other than that, filetype
determination is done by looking at various parts of a file and comparing
what's found ("magic numbers") to a database (the "magic" file).
So, for example, my system "knows" a certain file is a command script
because the first 256 characters are all ASCII (which means it's probably a
text file of some sort) and the file permissions are set such that it's
executable (not merely readable).
It also knows that a certain file is an ELF-format executable for a 32-bit
little-endian MIPS processor with a version 1 architecture (ie it will run
on *old* MIPS cpus as well as newer ones) because the bytes at offset 1 are
"ELF", at offset 4 there's a binary "1" (which in this context means 32-bit
not 64-bit), at offset 5 there's another "1" (little-endian), at offset 16
"2" means "executable", and at offset 18 "0" means "MIPS" (not Sparc,
80x86, 68000, etc).
Some magic numbers are much simpler to decode, of course: a file that
begins with "GIF89a" is a GIF file, surprise, surprise. And the more you
dig, the more detail you can work out.
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
<And another point. There are a lot of ways to make (say) an oscillator.
<If you're designing something you probably only need to know a couple of
<them. But if you're repairing it, you'd better understand the one that
<was used.
True! I have the advantage that I see designs and immediatly see the
core of the design with all the fluff removed. But it's years of
experience and a good basic grounding in circuit theory that allows me to
look st stuff I've never seen and synthsize the elements of the design in
my head and troubleshoot it, right down to seeing it's weak points of
likely failure.
Allison
<Related to this, there's a myth that design is difficult, but
design is easy, it's a process. The initial creative thought is hard.
<faultfinding/repair can be done by almost anybody. Well, having done
<both, I personally find them equally difficult. Perhaps that means I'm
<no good at it, but...
Troubleshooting is a very complex process that I've never been able to
teach to anyone but those that naturally could. For me troubleshooting
is something that I find natural and easy. I carry that to design as
just a different problem to solve (cheaper, faster, better; pick any two).
But working with field circus underscored that thinking is not something
you can mandate.
Allison
At 07:58 PM 6/10/98 -0500, Doug Yowza wrote:
>auctions. I'd suggest that the exact opposite is true. Whenever somebody
>asks this list "how much is this thing worth", the answer is invariably
>"whatever somebody is willing to pay". Basically, valuation of
>collectibles is a democratic process not an analytical one belonging to
>some exclusive domain of experts.
Exactly, hence the value of an auction environment. That is what "whatever
someone is willing to pay" means, isn't it?
-
- john higginbotham ____________________________
- webmaster www.pntprinting.com -
- limbo limbo.netpath.net -
Thanks for the advice -- it worked just fine!. Now...Windows (3.1) setup hangs when loading...when it's still in the DOS screens (before starting the Windows part.) Any ideas?
manney(a)lrbcg.com
"Un sot trouve toujours un plus sot qui l'admire."
>Most (all?) GRiDs allow the boot device to be selected by holding down a
>key at boot time:
>'F': floppy
>'H': hard disk
>'B': bubble disk
>'R': ROM disk
>etc.
I'm also hav
manney(a)lrbcg.com
"Un sot trouve toujours un plus sot qui l'admire."
