>> The basic concept would be to simply sample the MFM (or RLL) channel
>> code at somewhere around 50 MHz as it is being written, and store the
>> data on the ATA drive. The interface would keep one track buffered in
>> RAM. Whenever the host requests a head change or seek, the buffer would
>> be written to the ATA drive (if it is dirty), and reloaded with the data
>> for the new track.
>> This would require a much larger ATA drive than the original drive it is
>> emulating, 102K bytes per track. To emulate a Maxtor 2190, this requires a 2G
>> ATA drive. You could even emulate drives larger than that by emulating more
>> cylinders.
> This is an intriguing concept. But would it be any more difficult to
> decode the data being written by the MFM controller and written digitally
> on the IDE drive to improve efficiency? Would this make reading the data
> back difficult?
No, anything you need is just imense CPU power. Recalculate
the bytes from the MFM stream and store it on a different
drive (that must be local, not visible to the Host). And
backwards generate the MFM data from the ATA data. Timing
bit arsh if you want to do it in real time, but since a
local CPU is already usefull for disk (ATA) controll and
conferting (can also be done by hardware) there could
also be some 256 Meg of mem for building/editing the MFM
stream and transmit it later (when ready).
And since w hafe the room of a full or half height drive
available, it could be put in replacement for the original
drive.
Gruss
hans
--
Ich denke, also bin ich, also gut
HRK
>> I stumbled on this site a while back and a few on the list may be
>> interested. Postings of want to buy and sell of "classic" type systems.
>> I have not had any response from the post I put there several months back -
>> Looking for DEC equipment but others may have better luck.
>> http://www.xs4all.nl/~rimmer/guest.htm
> Were you aware of the fact that the listed site is in the Netherlands? Just
> curious as unless you specify US shipping only you may be greeted by replies
> from former Soviet block countries as I have on other Euro sales sites.
Same on eBay or anywhere else - the net doesn't end at the
borders of states (maybe but China and North Korea). If you
insit on special rules, like only cash, no sale to white men,
or only within a special county, you have to post it.
> Seems Czechs, Romanians, East Germans
East Germans ? Geee - did you miss some years ? They have
nowadays the newer PCs :)
> and all the like are just anxious as can be to
> get US technology, old or new and in many cases without regard for shipping
> costs.
This time is gone since years - when it comes to PC tech,
Taiwan ships as fast as they get payed - no matter who is
ordering.
> I'm not sure enough myself of customs laws of present day to go through
> all of that but I know at one time there were heavy restrictions on exports of
> hardware and software.
There are sill a lot of US enforced restrictions about
computer parts (And the US government still tryes to
pressure other countries to maintain similar rules),
but in fact they never have been a hurdle at all. They
just liftet the price (like any other law that tries
to forbid people to get what they want).
As a matter of fact, all this regulations just hit
the US economy more than any other.
As long as it is about the EU, there are no more import
taxes or special rules regarding computer parts. They
droped all EU taxes and most of the regional import
taxes on computers - So if something contains electronic
parts - just try to find some way to declare it as computer
parts.
Gruss
Hans
--
Ich denke, also bin ich, also gut
HRK
-----Original Message-----
From: David Williams <dlw(a)neosoft.com>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Thursday, 12 November 1998 16:36
Subject: Re: Unknown Apple // card images ref
Haven't tried that. I don't expect it to do much of anything but I'll give
it a shot
and let you know what happens. I still think it is a modem but I
can't imagine why it would have so many components.
Is there an AM7910 or 7911 chip on there?
That would peg it as a 300/1200-75 modem. (V21/V23)
That was one of the common chips used.
Geoff Roberts
Computer Systems Manager
Saint Marks College
Port Pirie South Australia.
My ICQ# is 1970476
Ph. 61-411-623-978 (Mobile)
61-8-8633-0619 (Home)
61-8-8633-8834 (Work-Direct)
61-8-8633-0104 (Fax)
Earlier there was a discussion of what PC stuff might be collectable and
valuable.
The other day I ran across an original Columbia PC. This one is a good
collectable. It was as it came from the factory with the original Floppy and
Hard drive. It also had the original keyboard with it. It was very clean and
had not been abused. It worked. In my 1983 Bytes they were asking $5000 for
it. I paid $6 at goodwill with the intention of putting it on ebay just to see
what it will bring. I am retireing from collecting but if I were going top sit
on a piece of equipment this would be a good example. My reasons in order of
priority: 1) first popular clone, 2) all the original -parts (including
screws), 3) Clean with no scratches, the type on the keyboard showed no wear,
4) Works (not essential - i bought it without testing it - $6 is not a great
gamble), 5) Rareity - Most of these go directly to scrap and have for years.
However it will be many more years before it is truly valuable, but I bet it
will be!
Paxton
I ran into a computer at a thrift store today called an AcerStation. It
was a thin machine, clearly designed to be a network client. I think
it's AT-class. The interesting thing is that when I booted it, the empty
floppy drive whirred as usual, then it said something along the lines of
its not being connected to a network and press any key to reboot. Is
this thing network bootable? I've never heard of a PC that could do
this.
Also: Could someone tell me the model number of the original NEC
Multisync? NEC's site has nothing about it, and I want to know if that's
it at the thrift store. Could someone also confirm that it can do VGA
modes?
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com
Yes it is totally off topic but I would be remiss
if I did not say THANK YOU to whoever it was who
posted.
Three weeks ago a post came across this list which
which stated that someone was wanting to sell thirteen
old arcade machines. The poster further stated that
he was posting this message only because he thought
these might be computer games.
Only because of his post to this list and
with only an email address to go on I was able to
make contact with the owner of these macines.
I learned that these were all priceless turn of the
century era penny arcade machines that had been
used at Disneyland in Anaheim and later at Disney World
in Orlando. I further learned that
they were going to be sold in an obscure auction in
Florida (I am in Florida) three days later.
To make a long story short, I was able to purchase
seven of the thirteen machines at a fraction of their
value.
The surfacing of these thirteen pieces is one of
the most significant finds of this type item in the
last ten years.
I have been collecting coin operated antiques for
twenty five years. This is the first time in all
those years that I have ever had an opportunity
to buy even one example of this type item. Because
someone posted the message to this list I now
am proudly in possesson of seven of them.
THANKYOU, whoever you were.
Bob Wood
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com
Hello To whom this may concern,
I was referred to your e-mail.
The reason I'm writing is because over the last year when different
people have found out that I had an old "Apple II C" computer that had all
original components such as, keyboard(model# A254101), Unidisk 3.5
drive(model# A2M2053) , monitor(model# G-090S) and even has an old Image
Writer II printer and all the components of the system were clean and in
excellent working order. They asked excitedly if I was interested in
selling it and even made unsolicited offers (some a helluva lot higher than
others). Offers that caused me enough surprise to exclaim " You gotta be
joking !".
I'm curious about the true value of this Apple II system now because I
have a new system . I would truly appreciate any and all information that
you could provide.
Thank you for your time and consideration and I'll be looking forward to
your response.
With Best Regards
Christopher J. Perron
>On Wed, 11 Nov 1998, Max Eskin wrote:
>
>> Also: Could someone tell me the model number of the original NEC
>> Multisync? NEC's site has nothing about it, and I want to know if that's
>> it at the thrift store. Could someone also confirm that it can do VGA
>> modes?
>
>Depends on what you mean by NEC Multisync. A number of models have been
>mentioned in response to your original request. I believe Dan Burrow's
>summary corresponds to the NEC Multisync II. Not the 2A or other members
>of the "2" series or 3's or higher. Note the Roman numeral. Says
>"Multisync II" right on the front.
I was quoting from the manual for the JC1401P3A for what it is worth. It
also has all the pin outs for both analog and digital along with other
related stuff. My scanner is down right now but I could FAX it if someone
wants.
Dan
>This is the one with the 9-pin D-sub and is the only one I am aware of
>that will sync 15.5KHz analog which is sub VGA video for Atari ST, Amiga
>and Apple IIgs.
>
>The model number is JC 1402 HMA. It will do 640x480 VGA interlaced or
>non-interlaced. It can step to 800x600 but someone mentioned it was
>pretty poor and I believe part of the reason is it is interlace only.
>
>It also, as Dan points out, has TTL capabilities. I haven't made use of
>that aspect. I have used it on built-in Macintosh video and some Nubus
>cards that are theoretically VGA friendly but produce sync on green
>(green screen?) and just otherwise don't work with normal VGA. If it is
>indeed a "II" model, I'd say jump at the opportunity. The dot pitch isn't
>great at .31 but it is sharp enough. The key though is the fact that it
>is the Rosetta stone of monitors and it is worth having in your toolbox.
>
>For monitor reference you might try the following:
>
>http://www.telalink.net/~griffin/mondata.html
>
>which is a straight 120K or so listing of every model.
>
>Or use:
>
>http://www.telalink.net/~griffin/monitor.html
>
>for a search engine.
>
>I believe the above addresses are currently correct. I think any
>reference to nashville.net is an older location. At the current moment, I
>believe nashville will correctly alias to telalink.
>
>The information is sparse. Changes are made from time to time, so I guess
>they are trying to maintain it with limited staff time. The database is
>always worth a look when dealing with an unknown monitor, but no promises.
>
>
>
> -- Stephen Dauphin
>
I've been thinking about designing an interface card to replace ST-506
>interface drives with ATA (IDE) drives. It's getting hard to find
>Maxtor 2190s at a decent price, and I'm not sure how many more years it
>will be possible to keep them running at all.
>
>The basic concept would be to simply sample the MFM (or RLL) channel
>code at somewhere around 50 MHz as it is being written, and store the
>data on the ATA drive. The interface would keep one track buffered in
>RAM. Whenever the host requests a head change or seek, the buffer would
>be written to the ATA drive (if it is dirty), and reloaded with the data
>for the new track.
>
>This would require a much larger ATA drive than the original drive it is
>emulating, 102K bytes per track. To emulate a Maxtor 2190, this requires a
2G
>ATA drive. You could even emulate drives larger than that by emulating
more
>cylinders.
>
>The tricky part is that it might be necessary for the simulated drive
>to mimic the effect that write precompensation in the host's controller
>is intended to circumvent.
>
>
>
Such a card already exists- I saw someone selling one on the Obsolete
Computer Helpline.
--
-Jason Willgruber
(roblwill(a)usaor.net)
ICQ#: 1730318
<http://members.tripod.com/general_1>
< I could've sworn you spoke rather higher of it about a year
< ago...anyway, I guess I can now understand why it is chosen as the best
< example of Bill Gates' work :) but why is it always discussed (on Trimph
< of the Nerds, for example) in terms of early personal software? Is it
< that this was the best program for the Altair?
The later versions were fairly stable and useful. Keep in mind at that
time software was scarce (prior to 1977) so I tended to live with some
things. It was landmark code in and one of its founders is a billionair
now so it's remarkable. Keep inmind Triumph of the nerds was
retrorevisonist history. Looking back is not the same as remembering the
frustration of having actually used it.
Allison