Actually, my favorites are the ones where the tractors are right
on the platen. No jams and no wasted paper. I once had an Epson
MX-150 that jammed something awful. I got rid of that. An example
of the former is the Okidata 120, which I used with my C-64. But
to tell you the truth, I can't stand wasted paper almost as much
as wasted hardware ;)
>Most older dot-matrix printers had tractors after the
platten/printhead.
>Some of them, like my Sanders units have 2 sets of tractors, before and
>after the platten.
>
>Yes, it does mean that you waste a sheet of paper when you finish
>printing something - you have to do an extra formfeed. On the other
hand,
>I'm quite sure it saves a lot of paper due to the reduction in the
number
>of paper jams. A lot of 'push' type tractors seem to be great at
mangling
>paper...
>
>-tony
>
>
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On Apr 14, 12:04, Tim Shoppa wrote:
> > ISTR an article on alt.folklore.computers a year or so back, giving the
name
> > of the lawyer who sent the first officially-recorded unsolicited email
spam.
>
> I think you're talking about Canter and Siegel, right? While this
> wasn't the "first" spam, Canter and Siegel's "GREEN CARD" postings
> are among the best well-known, and in many ways the most irritating.
> (Canter went on the talk-show circuit after the spam disaster to
> promote his book which claimed to show others how to succeed in
> internet marketing.)
Thanks, Tim, that's what I was thinking of. And thanks to whoever dug out the
posting (sorry no attribution, I hit "delete" a bit too quick). Seems my
memory was close but not wholly accurate. How unusual :-)
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
On Apr 14, 23:07, Tony Duell wrote:
> Ouch!!!. Even my standard test for floor loading wouldn't have found that
> (= Jump up and down hard. If the floor doesn't give way, put the machine
> on it and jump up and down again. If it's still OK, it'll probably stay
> that way).
Jim now has the flooring from our Department's old machine room -- and now I
know why those floor panels are so heavy :-)
> > BTW, the little DX11-alike in the 11/73 was accompanied by a "Camtech
> > Ethernet QBus Interface".
> The only thing that reminds me of is the Camtech JNT PADs and iso-ether
> PADs used in UK universities as part of the JANET network. I've not got
> any, alas (I'd quite like one...), but I seem to remember that at least
> the JNT pads were Z-80 based and had a synchronous serial port connection
> to the outside world talking some kind of X25...
We had several, but they all got cannibalised. They were indeed Z80-based, and
had lots of SIOs, DARTs, and a few PIOs in them too. Neat cases as well.
> I have no idea what it talked instead of TCP/IP, but it'll probably be
> something that was common in the UK at the time. Any ideas? I can look
> back through PERQ and Torch XXX manuals to see if anything leaps out..
I've no idea. I imagined that Camtech made other ethernet stuff, and if they
could make such a good-looking QBus ethernet i/f I thought there must be more
around. I've never found any, though, nor have I ever found anyone who could
tell me much about long-gone Camtech (apart from JNT PADs).
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
I looked at the pictures, and double checked my Olivetti M24, recently
obtained from Andrew Davie. They are the same machine.
This one also has a dead power suppy but none of the corrosion. The fan
works because it is mains powered, 240v in this case.
Hans Olminkhof
-----Original Message-----
From: David Williams <dlw(a)trailingedge.com>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Tuesday, 14 April 1998 15:40
Subject: AT&T 6300 PSU Question
I went to power up my AT&T 6300, which hasn't been up for about 4
years, and noticed that the PSU fan was coming on but the drives and
motherboard didn't seem to be getting power. I opened up the system
and was surprised to find the power supply was corroding. Now I'm
not a PSU expert by any means so this was unexpected. The upper
motherboard appears to be ok but I haven't checked the lower
motherboard yet. It appears I can pull the PSU out and replace it
but I'm curious as to why it began corroding in the first place. You
can see pictures of it on my web site on the AT&T 6300 page or at:
http://www.trailingedge.com/~dlw/comp/images/attpwr1.jpghttp://www.trailingedge.com/~dlw/comp/images/attpwr2.jpg
[SNIP]
>shortwave radio.
Speaking of shortwave, imagine if the FCC authorize commerce on
ham radio! Ugh...
I am completely unfamiliar with S-100 systems, so could you please
explain... were S-100 technologically superior to PCs (i.e. IBM
PC 5150), or just aesthetically? As far as I know, they used an
older processor...
Was it just an issue of being used to them?
As for laissez-faire, I never have believed in it. It makes society
too concerned about money. This is proven when complete crap hardware
is released now, and people don't care because it's good _financially_
>And just to bring it back on topic...when consumer PCs came out (IBM,
>PET, Atari, Apple, etc.) those of us who built and used "real" micros
>(S-100s of course) lamented that fact that the microcomputer market was
>being overrun by large corporations bent on destroying the
laissez-faire
>market of the mid 70s. Sound familiar?
> Jack "I use an IMSAI, not those toy computers" Peacock
>
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I have a minor problem with a dot matrix printer, and its feeder.
It is an Epson LQ-500. It has a removable set of tractors, which
mounts on top. However, they mount on the output end. This means that
there must be paper in the tractors that is beyond the print head,
which means that about a sheet of paper must be wasted. Could someone
explain to me what is the idea behind this system?
______________________________________________________
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> And to make matters even worse, it was a husband and wife lawyer team!
Birds of a feather, um, make that vultures, flock together...
Jack "birdbrain" Peacock
> From: Max Eskin [mailto:maxeskin@hotmail.com]
> there must be paper in the tractors that is beyond the print head,
> which means that about a sheet of paper must be wasted. Could someone
> explain to me what is the idea behind this system?
At one time nearly all tractor feed printers pulled instead of pushed.
Demand documents (i.e. tear off right above the print head) was not a
concern for most printers. Reports were printed in batches, then
separated by operators. Also, the paper was less likely to jam if you
pull it through the paper path, rather than try to push it through.
Ever see a paper jam on a 1200LPM chain printer? The operator could
spend a good 15-20 minutes clearing out bits of shredded paper.
Computer time was more expensive than the paper, no one cared if a few
pages got wasted for form feeds.
Jack peacock
On Apr 14, 11:06, Allison J Parent wrote:
> Try about 5-6 years and it was there before but you could get the offender
> tossed before that. Also When AOL opened to the net it seemed to add to
> the fray.
ISTR an article on alt.folklore.computers a year or so back, giving the name of
the lawyer who sent the first officially-recorded unsolicited email spam. IIRC
he lost his account. I can't remember the details, so it might be hard to find
(and I'm not sure of the details, but 5-6 years ago sounds about right).
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
On Apr 14, 0:40, David Williams wrote:
> Subject: AT&T 6300 PSU Question
> I went to power up my AT&T 6300, which hasn't been up for about 4
> years, and noticed that the PSU fan was coming on but the drives and
> motherboard didn't seem to be getting power. I opened up the system
> and was surprised to find the power supply was corroding.
> You can see pictures of it on my web site on the AT&T 6300 page
Jason's comment about liquid sounds about right. It looks more like something
was spilt onto it, than as if something self-destructed. Anyway, it's usually
electrolytic capacitors that self-destruct in that way, and that normally
happens when there's a voltage there.
> Any ideas? Also, anyone have a spare PSU? I don't really want to go
> buy another AT&T 6300 just for this but suspect the PSU won't be easy
> to obtain otherwise.
I'd attempt a repair, or at least some further investigation.
The case looks pretty yucky but from the pictures, the physical damage might
not be that great. I'd take it apart and attack the case with a wire brush or
steel wool, and a very light touch of oil or WD40. The terminals don't look
too bad at all, a little brushing (stiff toothbrush preferred, or a brass wire
brush or fine steel wool) and a little WD40 should work wonders. Make sure you
wipe off any excess WD40, though.
Depending on how bad it is inside, it might be worth washing, but do make sure
that (1) any capacitors are discharged before you get it wet, and (2)
everything is *completely* dry before you try applying power! Again, a
toothbrush is a useful tool.
In many similar PSUs, the fan is driven from the 12V line. If that's the case
here, it implies that at least part of the circuitry is working, which is very
encouraging. Perhaps only the 5V line is dead. It's hard to suggest much more
without more information, and without seeing the inside.
If you do try anything, apart from the obvious precautions, be aware that there
are some very high voltages inside switch mode PSUs, as high as 300V. Also,
many PSUs won't operate correctly without a load on at least the 5V line; at
best, they won't regulate properly, at worst, they can be damaged.
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
today at goodwill I found a Advance Micro Device AM2900 Evaluation &
Learning Kit in the it's box (very nice design on it) with one worksheet.
the unit was only $5.
Sorry about the extra public traffic (and this one too). I didn't look
at the "reply to" on Charles' message.
--------------------------------------------------------------------
Russ Blakeman
RB Custom Services / Rt. 1 Box 62E / Harned, KY USA 40144
Phone: (502) 756-1749 Data/Fax:(502) 756-6991
Email: rhblake(a)bbtel.com or rhblake(a)bigfoot.com
Website: http://members.tripod.com/~RHBLAKE/
ICQ # 1714857
* Parts/Service/Upgrades and more for MOST Computers*
--------------------------------------------------------------------
On 1998-04-12 classiccmp(a)u.washington.edu said to lisard(a)zetnet.co.uk
:I think we all would expect all the
:subscribers to this list (and the other lists as well) to conduct
:themselves in a civilized and honourable way [...]
rotflmao
On 1998-04-12 classiccmp(a)u.washington.edu said to lisard(a)zetnet.co.uk
:... I only hope that there is a "silent
:majority" who does not speak but disapproves them and this is the
:only reason that keeps me from leaving conmans and their helpers to
:their destiny by leaving this list.
please, since you clearly haven't found any, assume you are wrong and
bugger off.
--
Communa (together) we remember... we'll see you falling
you know soft spoken changes nothing to sing within her...
This is new. Just brought the uVAX up again. I sent ONE message to Usenet
mentioning the address.
I now made it to some luser's spam list!
This is the new thing...
The spam appears to be in Japanese?
I guess this will be the first spammer I mail that can UNDERSTAND what they're
being mailed! (A-CNH)
The question is, just out of curiosity, when did Usenet deteriorate to the
point that spamming started?
Was it around the time AOL let people on Internet? :)
(J/k!)
-------
My PS/2 Model 70 is a 386, released around 1990. It is the most
recent machine I have seen to have ROM BASIC, with IBM DOS 3.3's
BASIC.EXE jumping just fine.
>
>Here's one I've never run into, oddly enough. IBM PCs 5150 throrugh
5170
>had the BASIC ROM and BASIC.EXE and BASICA.EXE included with PC-DOS
through
>4.0 just jump to the code on the ROM.
>
>Later models (PS/2s) still have the Cassette BASIC, but don't seem to
be
>able to run the PC-DOS BASICs. Did IBM break the BASIC ROM after the
5170
>model?
>
>--
>David Wollmann |
>dwollmann(a)ibmhelp.com | Support for legacy IBM products.
>DST ibmhelp.com Technical Support | Data, document and file conversion
for IBM
>http://www.ibmhelp.com/ | legacy file and media formats.
>
>
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com
Here's one I've never run into, oddly enough. IBM PCs 5150 throrugh 5170
had the BASIC ROM and BASIC.EXE and BASICA.EXE included with PC-DOS through
4.0 just jump to the code on the ROM.
Later models (PS/2s) still have the Cassette BASIC, but don't seem to be
able to run the PC-DOS BASICs. Did IBM break the BASIC ROM after the 5170
model?
--
David Wollmann |
dwollmann(a)ibmhelp.com | Support for legacy IBM products.
DST ibmhelp.com Technical Support | Data, document and file conversion for IBM
http://www.ibmhelp.com/ | legacy file and media formats.
<years. It happened shortly after NSF lifted the ban on commercial traffi
<and the 'net became better known to the public. Sure enough, a bunch of
<marketeers with more greed than brains saw Usenet as a vast new territor
<instead of what it was intended to be.
Try about 5-6 years and it was there before but you could get the offender
tossed before that. Also When AOL opened to the net it seemed to add to
the fray.
<The spam started. It has been throttled back to a degree, thanks largel
<to the efforts of the anti-spam crowd (consisting mainly of sysadmins), b
I haven't seen it slow. I've just about stopped posting in newsgroups
and stay away from many web pages where they appear to do address capture.
I don't even write in maillists (alt.sys.PDP8 to name one) that echo to
newsgroups for the same reason. I'm tired of getting junkmail from
some_bimbo(a)earthlink.com that really isn't earthlink and is likely a man.
Even with reducing presence and using munged address in most places I
still get the crap.
I can live with commercial but the sex for sale is unacceptable.
Allison
I don't have graphical internet access, so I can't see the pictures,
but could it be that electrolyte spilled from one of the
capactiors?
Just an idea...
>
>On 14 Apr 98 at 1:57, jpero(a)cgo.wave.ca wrote:
>
>> Wow! Looks like something have exploded inside and left there,
>> eating away those metals...or a cat had sprayed it or mouse have
>> known to get inside via a open card slot and pee. And leave rice
>> sized BM's inside. This kind of corrsion looks like much liquid have
>> left in there, judging by the patterns of corrsion. Did something
>> have dripped on that computer? High humidry is out, you have good
>> metals anywhere else because I had some that was stored inside a
>> closet with high humidry and came out heavily corroded clone power
>> supply box.
>
>I thought about that but the system has been sealed fairly well since
>I put it in my climate controlled storage space. Still, it does look
>like something was spilt on it. No open slots or anything so I don't
>know what could have gotten inside.
>
>I have another AT&T PSU I've been using to power the hard drive on my
>Amiga 1000. I may find a new power supply for the hard drive and use
>that one as a replacement for the corroded one. Still, it would be
>nice to know if something was dumped inside or the PSU itself
>released something.
>
>> BTW, what kind of camera and type of lens used you have used to take
>> this pics? That's very close up work and very sharp.
>
>I used a Kodak DC210 digital camera I borrowed from work. It's an
>$800 camera so I'd hope it would take decent pictures. :-) I'm using
>it to redo most of the images on my web site. It's a great camera.
>And those images were taken at it's lower resolution.
>
>-----
>David Williams - Computer Packrat
>dlw(a)trailingedge.com
>http://www.trailingedge
>
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com
I recently received a BULL XPS 100 mini frame from out local college with
all the manuals and disks.. etc It is a unix box, and I was curious if
anyone has had any experience with these things? And if they can point
me in the right direction to get this thing to boot :>
Thanx
Kenny
At 08:32 AM 4/11/98 PDT, you wrote:
>Wait a second, ARE there private newsgroups on this topic? I thought
>it was just an idea everyone proposed but never did...
Not that I know of. If there are, they're not letting me in. (A good idea
anyway, I suppose.)
>>It has. It comes up every now and then on every mailing list. What
>>usually happens is that those who want a newsgroup go off a create a
>>newsgroup, and the ones who can't access or don't like newsgroups stick
I was speaking of mailing lists in general. As in the Land Rover list,
which after many such suggestions finally split into Series and Coil Sprung
lists, and now also has a newsgroup.
Sometimes it goes the other way; I suspect rec.equestrian was around long
before the dressage list.
--------------------------------------------------------------------- O-
Uncle Roger "There is pleasure pure in being mad
roger(a)sinasohn.com that none but madmen know."
Roger Louis Sinasohn & Associates
San Francisco, California http://www.sinasohn.com/
At 12:28 PM 4/12/98 +0000, you wrote:
>> I promise that we CAN. I didn't say anything about willing to. However,
>> should I come across one, you'll be the first to know.
>> Tim D. Hotze
>> >Is this a promise?
>> >
>> > I'm sure that we could find a TRS-80 model 1 CASE
>> >> somewhere for you.
But if you did, would you want to risk your own reputation by sending it to
him? Goodness knows, it might not have the right serial number or
something, and then you'd be branded a con man for life! 8^)
--------------------------------------------------------------------- O-
Uncle Roger "There is pleasure pure in being mad
roger(a)sinasohn.com that none but madmen know."
Roger Louis Sinasohn & Associates
San Francisco, California http://www.sinasohn.com/
J. Maynard Gelinas wrote:
> OK, This is mildly on topic. My monitor is an HP 1097C, making
> it at least 10 years old. However, I am using it with a modern PC, so
> that's where the 'on topic' issue gets a little iffy. I'm sure there
> are plenty of people here who can answer this question. A pointer to
> a FAQ would be most welcome.
Here's one interesting URL:
http://rugmd0.chem.rug.nl/~everdij/hitachi.html
I've seen others as well but that was the one I made a bookmark to. :-)
> These old monitors are Fixed frequency, unlike our modern
> monitors which multisync. The 1097C supports only a 78.125 khz
> Horizontal Scan Rate and a 72hz Vertical Refresh Rate. Now a couple
> of years ago I foolishly bought one of those cards by Mirage
> (www.mirage-mmc.com) which is supposed to be a 'fixed freq video
> card'. Actually, it's an OEM Diamond card, basically an S3/968 video
> processor with an IBM 52x RAMDAC - ala Diamond Stealth VRAM. The
> fixed Freq hacks are basically a resistor (and a jumper selection) to
> drive sync over green, and a homebrew PROM to skew the VESA
> frequencies for several video and text modes.
Hmmm, interesting. Photon also makes fixed-freq. boards, and I was tempted to
get one for an old SuperMac monitor I have. I also once attempted to fix a
batch of Moniterm monitors that had various problems, and the one board I
found to use with them in Windows was a Vermont Microsystems model that cost
way too much to begin with, and is now no longer made. There was also no
driver later than Windows 3.1, so my dad has it now since he still has a slow
486. Anyhow, I thought Photon's boards were probably better than Mirage's, I
forget why. They are at www.photonweb.com I think, but I can't seem to get
there at the moment.
> It works, but Mirage hasn't been too helpful with getting a
> variety of XFree86 modelines, even though they claim to support Linux
Darn, shame on them.
> and XFree86. They give out _one_ modeline for 1280 x 1024, which they
Well at least it works eh? Can you at least upgrade the VRAM to get more
colors, or did you want low-res for some other reason?
> swiped from the XFree86 distribution in 'Monitors.txt'. For Windows
> and Dos, they give out a video driver which seems to work just fine.
> It will even display 320x200 full screen (Quake works great in DOS!),
> and boots to a functional 80x24 col text mode. How the hell do they
> do this?
>
> Here is how I'm calculating my video modes based in the
> XFree86VideoModes HOWTO (found in every Redhat 5 distribution):
You understood what they said, that your horizontal line includes enough
"dots" to allow time for the gun to sweep back to the beginning of the next
line? So to get 1280 dots across, you might need to allow 1350-1400ish
dot-clock-periods per line (or maybe even more).
(dots/sec) / (dots/line) = lines/sec = lines/frame * frames/sec
For example:
if you want 1024 lines, allow around 1150 total lines (to allow time to sweep
back to top-left between frames); so
1150 lines/frame * 72 frames/sec = (x dots/sec) / (1350 dots/line)
now solve for x to get the dot clock, and to double check the formula, make
sure that all the units cancel out.
x dots/sec = 1150 lines/frame * 72 frames/sec * 1350 dots/line
yep, line / line * frame / frame * dots / sec = dots / sec
and you need a dot clock of 111,780,000 dots/sec
>
> Dot Clock Per Second
> Total Horizontal Pixels Per Line = --------------------------
> Horizontal Scanning Rate
This is right, dots / line * line / sec = dots/sec
>
> Since my refresh rate must be at 72hz to sync with the HP1097C:
>
> Dot Clock
> Refresh Rate = -------------------------------------------------
> Horizontal Frame Length * Vertical Frame Length
frames / sec = (dots / sec) / (dots / line * lines / frame)
= (dots / sec) / (dots / frame)
= frames / sec
yep
>
> So, it's really more constructive to think of this as how many
> pixels _total_ do I need to display in order to get a 72 hz vertical
> scan rate with any arbitrary dot clock? In this case I need
>
> Dot Clock
> Total Pixels Per Frame (HFLxVFL) = -------------
> Refresh Rate
You did algebra on above, correct
>
> Since I know my Horizontal Pixels Per Line, I can use this to
> determine the number of vertical lines which will support a 72 hz
> refresh rate.... hmmm, this is where things get sticky. We'll start
> with a DCL of 10Mhz...
Why? That is too slow a dot clock to be useful. You should work backwards -
figure out what resolution you want, find the corresponding dot clock, pick
the closest supported dot clock to the one you calculated, and then calculate
forward again to figure out what resolution you can actually get. You can
also play with the blanking intervals, because the monitor has a minimum time
that it takes for the gun to scan back to the beginning of the next line (or
next frame), but no maximum time. If your supported dot clock is a little too
slow, you can waste the time in the blanking interval to keep a standard
resolution, or else optimize the resolution to use up all the available
time/line. But with a fixed frequency monitor, you must also keep the
horizontal and vertical scan rates in "range" - however wide that happens to
be. So really, with those two constraints plus your quantized available dot
clocks, that's why "fixed frequency" also means "fixed resolution". If the
monitor was designed for 1280 x 1024, the card must output about that many
dots in each frame and at the correct frame rate. You could output half the
dots per line, and also halve the dot clock, and halve all the other values
(front porch, back porch, vertical blanking interval, etc.) but if you tried
to also cut the vertical resolution in half, you'd violate the line rate
constraint. So as you say below, line doubling makes a lot of sense; you
could simulate 640 x 480 on a 1280 x 960 screen by halving the dot clock and
line-doubling each line. Text mode can be simulated by custom programming on
the graphics chip, so that it actually produces dot data at 640 x 480.
Keep in mind the monitor will have "total bandwidth" limitations too - it
might not be able to accept too fast a dot clock even if you don't exceed the
horizontal scan rate or frame rate.
<second message>
> BTW: no one responded to this message, so I guess no one
I'm sorry, I must have missed it. Normally that subject would catch my eye.
:-)
> knew the answer. I received a responce to a USENET post about
> this and thought there might be some interest in the group.
> The VGA spec supports 'doublescan' mode for low resolution
> compatability with CGA apps. This essentially forces the card
Cool, makes sense, I didn't know that was a standard.
I used to have a DOS CGA simulator for the Hercules card, several years ago,
that
must have worked this way also; simulating 640 x 200 on a 720 x 400-something
display. The displayable area was smaller too, so evidently they only used
640 of the available 720 dots across. It was very useful for playing old CGA
games on my mono card anyhow.
> to draw each horizontal line twice, thus doubling the refresh
> rate (or your vertical resolution in half at the same refresh
> rate) at any arbitrary horizontal scan rate. Well, some
> chipsets (like the 968, Matrox Millenium, and most ATI
> chipsets), allow for tripplescanning which does exactly what
> one would expect... it scans each horizontal line three times
> before skipping down to the next line, thus allowing one to
> drop down to a third of the vertical resolution at the same
> refresh rate (same horizontal rate always, of course).
Hmmm, so 1024 / 3 = 341, 960 / 3 = 320, I don't see how that would be very
useful since there aren't many (any?) modes that have vertical res. in the
320-340ish range. Maybe it could be stretched a little to get 640 x 400.
Quad-scan would be useful for doing 320 x 200, or they could just be wasteful
with memory and do 4 pixels in VRAM for every pixel and get 640 x 400 out of
it.
800 x 600 would just be plain nasty. :-)
>
> OK. XFree86 and SVGAlib don't support tripplescan mode, but
> they do support doublescan mode because it's part of the VGA
> spec. Tripplescan is vendor specific, and so thus is enabled
> in different ways for each chipset. I'm attempting to hack
> svgalib to support tripplescan for the S3/968... waiting for
XFree you mean, or svgalib?
> the 968 docs to arrive so I can find the register and register
> values to set for my adapter. The rest seems fairly easy, just
> hack in parsing for 'tripplescan' on the modeline and such.
>
> Why does this matter to you? Well, if you have an Hitachi
> HM-4119, HP1097C, or somesuch fixed freq monitor, getting it to
> work under Linux is pretty easy once you know the trick. Why
> buy a $1500 monitor when you've got a perfectly fine one
> sitting on your VaxStation 3100? Well, for the purposes of
> this list, why not just use the 3100 as the xterm... but that
> defeats the purpose of this message. ;-)
Yep, I've been wanting to do this for years. I did it briefly with that
Vermont card (and kept the hercules card also, for text mode, because the
Vermont card made no attempt to support any standard modes at all; it was
really intended to be a secondary display for CAD) but couldn't do any newer
Windows or X with it. It also had an interesting high-level proprietary
command language for drawing the primitives; I got the impression from its
sketchy docs that you could actually send textual commands to its I/O port and
it would interpret them in real-time. That and being an ISA card made it
kindof slow. And it only had enough VRAM to do 16 colors, and Vermont wanted
an arm and a leg to upgrade to 256 colors.
My SuperMac monitor worked fine with my ATI All-in-Wonder, but only in Windows
95, for which there is a nice driver that lets you tweak every parameter.
Tweaking similarly might be possible, if harder, in X, but I haven't tried it
yet. Unfortunately the Win95 ATI driver won't tell me the numbers to plug
into X modelines; I wish it would, but there are just these arrow buttons on
the screen to adjust position, size, etc. My experience has been, if you are
in the ballpark and the monitor is behaving itself, you can tweak it a little
bit to adjust size and position; but then all of a sudden it will just go
bonkers, and to get back to where you were right before that, you have to
overshoot and then edge your way back (not moving the mouse, because
you can't see the on-screen button anymore!) So reproducing the same results
with xvidtune's tricky interface would be difficult.
Someday, maybe somebody will produce a video card with a video-scaling chip
built-in, so that you can multiply dots by something other than a whole
number. This is the sort of thing that's already being done for LCD video
projectors, video digitizers that can put the image into an arbitrarily-sized
window (like my All-in-Wonder), the digital HDTVs now being designed, and
maybe even some of the better laptop displays. I don't see why if they can do
it for TV input they can't do it on the output signal as well. As the dot
clock asks for each output dot, the chip would just have to take into account
the colors of the adjacent dots, and blend smoothly; so to avoid having to
read VRAM at, say, 9x dot clock, it would have to have some fast registers to
store the values of the adjacent dots temporarily, and it could then read VRAM
at a mere 3x dot clock. Or, it could store 3 lines in its fast memory and
read the line past the next one during each horizontal blanking interval.
Maybe the need for fast VRAM is the limiting factor; no, because actually
scanning at 1280 x 960 requires 4x the speed of scanning at 640 x 480, whereas
simulating 640 x 480 at a dot clock to achieve 1280 x 960 only requires
reading VRAM at 3x the rate. So I don't know why this hasn't been done.
Maybe Photon does this, I'm not sure.
I think I'm going to post this on a newsgroup or two and see if we get any
better answers.
--
_______ KB7PWD @ KC7Y.AZ.US.NOAM ecloud(a)bigfoot.com
(_ | |_) Shawn T. Rutledge http://www.goodnet.com/~ecloud
__) | | \_____________________________________________________________
<today at goodwill I found a Advance Micro Device AM2900 Evaluation &
<Learning Kit in the it's box (very nice design on it) with one worksheet
<the unit was only $5.
I must be looking in all the wrong places. That's only my list for SBCs,
next time.
Allison
