I am risking the effects of that famous quote, "Better to be thought a
fool..."
I have a 15V DC powersupply that has no other rating on its sticker than
180 watts. Now, with my [extremely] limited knowledge, I did the simple
math and worked out that I could safely pull 12 amps out of this
PS...am I right? Does it really work this way?
Aaron
see below, plz
Dick
-----Original Message-----
From: jpero(a)cgocable.net <jpero(a)cgocable.net>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Thursday, July 01, 1999 5:34 PM
Subject: Re: State of the Hobby
>> Date: Thu, 1 Jul 1999 16:08:44 -0600
>> Reply-to: classiccmp(a)u.washington.edu
>> From: "Richard Erlacher" <edick(a)idcomm.com>
>> To: "Discussion re-collecting of classic computers"
<classiccmp(a)u.washington.edu>
>> Subject: Re: State of the Hobby
>> X-To: <classiccmp(a)u.washington.edu>
>
>> Well, just to put things in proportion, today, you can go to Best Buy and
>> get a 300+ MHz P-II computer with an 8gb HDD and 256K of RAM, etc, for
$600
>> including a nice 17" monitor.
>>
>> Dick
>
>Please snip off excess text while replying. BTW whoops 256K for a
>PII? U mean 256MB?
>
I do indeed! Sorry . . . rented fingers (lame excuse) . . .
>
>:-)
>
>Wizard
I just have to be contrary, here. I was given my first Mouse Systems
Optical Mouse back in '82. That was before either the Lisa or the Mac. I
don't exactly know what the giver thought/wished I would do with it, but
there it was. I was using CP/M at home and office though we did have an
MS-DOS machine.
If attention hadn't been called to the mouse by that time, I doubt someone
would have given me one.
Dick
-----Original Message-----
From: Tony Duell <ard(a)p850ug1.demon.co.uk>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Thursday, July 01, 1999 5:21 PM
Subject: Re: Article about collecting in Antique Trader.#
>> > I don't want to imply a direct technical link here. But it's clear that
the
>> > Macintosh was influenced by the Lisa. And that Windows was influenced
by
>> > the Macintosh.
>>
>> Objections!
>> IMHO Windows was _not_ influenced by the mac - at least not
>> at all before 3.x, and not heavyly before 9x. Let me explain:
>
>I wasn't implying a technical influence. Just that the Mac brought the
>mouse to the public's attention. And thus PCs had to get some kind of
>mouse/GUI. After all, the GUI on the Alto is very different from that on
>the Lisa, which is very different from that on the Mac (at least as I
>remember them).
>
>In any case, Windows 3.x was an important step. There were _very few_
>(that I remember) third party applications for Windows 1.x or 2.x. In
>fact those versions of Windows tended to come bundled with whatever
>applications needed them (I remember installing Excel on a PC in about
>1988 and it came with a run-time Windows 2.x IIRC).
>
>But Windows 3.0 appeared (to the user) as a different PC operating system
>(yes, _I_ know it was built on top of MS-DOS, but...). Now you could get
>point-n-drool programs for this OS on a PC.
>
>
>> The picture might look like:
>>
>> The Mouse ------------------------------;
>> | SideKick -'-> Windows 1.x/2.x -;-> MS Win
3.x -;-> MS Win 9x
>> | ,-> GEM -'
|
>> Alto -+-> D machines -> Apple Lisa -> Original Mac -'----------> MacOS
>7.0 -'-> ...
>> | | Close similarities
>> +-> PERQ
>
>
>OK, I can certainly accept that.
>
>All I was really commenting on was the fact that the Lisa attracts a
>price out of all proportion with it's significance. The PERQ and
>D-machines are important as well, but those don't tend to sell for $5000
>or whatever.
>
>> No, me'n either, but maybe the impact of the PC had been different -
>> these computers did pave the road to use other systems more willingly
>> not just by order of ones boss.
>
>I would be _very_ supprised if most of today's PC _users_ (as opposed to
>programmers, hackers, etc) started out building a ZX80 19 years ago..
>
>> P.S.: If you continue, I might be interested in getting a PERQ :)
>
>You should be. It's an interesting machine. Just be warned that
>microcoding is addictive...
>
>-tony
>
The phrase "prices...out of reach of people who can handle these machines"
sounds like you don't consider anyone with money to be technically
competent. I'm sure that's not what you meant... right?
Kai
-----Original Message-----
From: Max Eskin [mailto:max82@surfree.com]
Sent: Wednesday, June 30, 1999 3:10 PM
To: Discussion re-collecting of classic computers
Subject: Re: State of the Hobby
I agree that this is not a legitimate thing over which to become angry,
but there is an issue that this is driving the prices up, out of reach of
people who can handle these machines, and into the reach of people who
want to encase them in plastic and put them into their 500 sq.ft. living
room. This is causing some hostility.
--Max Eskin (max82(a)surfree.com)
http://scivault.hypermart.net: Ignorance is Impotence - Knowledge is Power
Hi,
Does anyone want a copy of the Operator's Guide for the XEROX 630 API/API
ECS Printer/Terminal? I also have a orignal Operator's Guide for the XEROX
D 25 Printer.
Joe
Can anyone point me at some sources of information on Data General, NeXT and/or
Philips (minis).
I'm looking to round off my collection by adding something from one or more of
these product lines but know little about them so I don't really know what to
look out for.
In particular I've heard mention of a DG MicroNOVA which sounds like it might
fit the bill in terms of size.
TIA.
TTFN - Pete.
--
Hardware & Software Engineer. Sound Engineer.
Collector of Arcade Machines, Games Consoles & Obsolete Computers (esp DEC)
peter.pachla(a)virgin.net |
peter.pachla(a)vectrex.freeserve.co.uk |
peter.pachla(a)wintermute.free-online.co.uk | www.wintermute.free-online.co.uk
--
In a message dated 6/29/99 6:14:14 PM Eastern Daylight Time, Tony Duell
writes:
> This means the history of computing is being distorted. Truely important
> machines are being forgotten. Other machines, much less significant, are
> being remembered. This is not a good thing.
>
> OK, let me ask a very simple question. I will give below the
> specification of 2 machines, both from around 1980. The questions are :
> Which do you think is the more historically important, and which one
> would fetch a higher price (Oh, and would anyone care to name the 2
> machines :-))
>
> OK. Machine A :
>
> Processor : Custom 16/20 bit CPU. Graphics processor. Z80-A for I/O
>
> RAM : 1Mbyte
>
> Storage : 8" floppy disk, 24Mbyte hard disk
>
> Keyboard : Full QWERTY keyboard, Keytronics
>
> Display : Bitmapped display, 768*1024 pixels (portrait monitor)
>
> Mouse : Sumagraphics Bit Pad 1
>
> Languages : Pascal, LISP, etc
>
> Comments : Version of the first commercially-sold graphics workstation
>
>
> Machine B :
>
> Processor : Z80A
>
> RAM : 1Kbyte
>
> Storage : Sockets to connect optional audio cassette recorder
>
> Keyboard : QWERTY membrane keyboaard
>
> Display : Text (22*23 or something like that), block graphics. Disappears
> when program running
>
> Mouse : You must be joking
>
> Languages : 4K ROM containing strange (integer only?) BASIC.
>
> Comments : Very inexpensive home computer
Machine B is very obviously a Sinclair ZX80 or ZX81. Pardon my confusion,
but are you saying that the ZX80/81 was "much less significant?" Perhaps I
misunderstand.
Millions of people worldwide were introduced to computers by these machines
(and their Timex cousins). Because of the low price, people bought them to
see if they "liked computing" -- if not, they could throw them away and only
be out $100 or so.
On the other hand, many, like myself, found they had a small talent for
working with computers -- in whatever capacity -- and thus found employment,
careers, and satisfaction because of their initial experience with
Timex/Sinclair computers.
> I think that if you own a classic computer you should learn how it works,
> how to use it, how to repair it, etc. Note, I am _NOT_ saying that you
> have to be qualified (after all, I'm not). I am not saying that you have
> to know everything before you start. I am saying, though, that you should
> want to learn.
The TS computers' simple but clever architecture encouraged learning all the
"how to's" you mention above.
But, perhaps I misunderstood what you were saying . . .
So: what are these two computers? Which is the most historically important,
and, in your opinion, which would fetch a higher price?
BTW, I use my Timex/Sinclair computers for some purpose at least five days
out of seven.
Regards,
Glen Goodwin
0/0
A well designed PSU will go into "thermal" shutdown, where the heat
produced by the pass transistors is detected and the PSU shuts down until
they cool off. A poorly designed PSU will go into "smoke" shutdown, where
the transistors release their blue smoke and then never work again. The
worst thing about the latter case is that when the transistors go into
thermal avalanche mode they cease operating according to specification and
the output of the supply could literally become nearly anything up to and
including the unregulated DC input from the rectifier (probably 23 volts in
this case)
--Chuck
At 02:03 PM 7/1/99 -0700, you wrote:
>Just out of curiosity, what
>could conceivably happen if I ran it at 12 amps and it couldn't handle the
>load? By the way, it is indeed an inexpensive, linear type...
Well, first of all, the linear type in that range aren't inexpensive . . .
Switchers are cheaper. That's why the use them so much. All that would
happen is that your voltage would drop out of regulation because the ripple
would cause the input voltage to be too low. I'd be not the least bit
afraid to try it. It probably won't break anything except maybe the fuse on
the supply.
-----Original Message-----
From: Aaron Christopher Finney <af-list(a)lafleur.wfi-inc.com>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Thursday, July 01, 1999 4:09 PM
Subject: Re: DC Power supply question...duh...
>Thanks, everyone who answered. I think I'm going to spring for another PS
>that I know is rated for the full 12 amps. Just out of curiosity, what
>could conceivably happen if I ran it at 12 amps and it couldn't handle the
>load? By the way, it is indeed an inexpensive, linear type...
>
>Thanks again,
>
>Aaron
>
>On Thu, 1 Jul 1999, Tony Duell wrote:
>
>> >
>> > I am risking the effects of that famous quote, "Better to be thought a
>> > fool..."
>> >
>> > I have a 15V DC powersupply that has no other rating on its sticker
than
>> > 180 watts. Now, with my [extremely] limited knowledge, I did the simple
>> > math and worked out that I could safely pull 12 amps out of this
>> > PS...am I right? Does it really work this way?
>>
>> In theory, yes.
>>
>> DC power = I.V. So 180W at 15V is, indeed, 12A.
>>
>> However, that is taking the '180W' to be the output power of the supply.
>> In many cases, the 180W is the maximum power it will consume from the
>> mains. And as power supplies are not 100% efficient, you don't get out
>> all the power you put in. In fact, the efficiency might only be 50%
>> (particularly if it's a linear PSU), so you could only draw 6A from it.
>>
>> I'd probably not take more than that from it, unless I _knew_ it was
>> designed to stand it.
>>
>> -tony
>>
>
