Hi,
I think its been over a week now as far as I can see. Just wondering if this
is just me not being able to get to this site. Has it gone away ??
http://www.vintagecomputermarketplace.com/
--
Kindest Regards,
Francesca Smith
"No Problems Only Solutions"
Lady Linux Internet Services
Baltimore, Maryland 21217
Hi All
One of the good things, or bad things, about being the "antique computer
guy" at our local auctions is that I'm a frequent recipient of all
things old, obsolete, or just unwanted. Someone mistakingly bought a lot
item he did not want so rather than trashing it, he gave to me. I felt
it was unique enough that maybe some of the brethren on ccomp might want it.
It's a Control Data CMD 9448-96 "phoenix" modular (removable/fixed) disk
drive in unknown condition. It reminds me of a RL01/02 disk. It looks to
have everything there but until I find a manual, I know little about it.
It is supposed to have a capacity around 80MB, has a 14" platter and is
real heavy; 120+ lbs, so shipping is probably out of the question.
If anyone wants it. It's yours for the taking as long as you come get
it. I'm in SE Arizona outside of Tucson (near tombstone) and I do make
trips to Phoenix or El Paso from time to time!
I'll keep it around in my storage shed for a while at least!
Cheers
Tom Ponsford
Item number: 270198584951
<http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=270198584951>
A Google returns this 1993 article in which the product is mentioned:
Just before Christmas, BT launched its VC7000 conference unit
(made by
Tandberg in Norway). This is a low-cost digital videophone, with a
25-centimetre colour cathode-ray tube screen which is switchable
between 64 and 128 kbit/s working. It costs ?7500. BT puts the
cost of
an hour's video call at 128 kbit/s to the US at ?168, but Mercury
promises to undercut this by nearly ?40. Call cost can be halved by
switching the phone to work at 64 kbit/s, but most serious users
prefer to pay more to get the better pictures and clearer sound
available from 128 kbit/s working. The British telecommunications
giant GPT is also selling 64-128 kbit/s systems, with screens
measuring up to 70 centimetres, for around ?40 000.
> The next question is, do the older drives have a filter on
> them such that they would not output the index along with
> the sector pulse?
The normal way to separate index form secotr pulses was to have a
non-retriggerable monostable that was triggered from the index sensor and
which had a period a little less than the time between sector holes. It
was triggered at the end of each hole. Normally it timed out after each
sector hole, but was still set when the index hole came after the last
sectore hole. The output of said monostabel sent the output of the index
hole sesnor to either the 'sector' line or the 'index' line.
What do you mean by 'older drives'? AFAIK no half-height 5.25" drive has
such a feature.
> The drive I'm planning on using is an old Qume drive with
> a IBM lable on the front. It is a QUMETRAK 142. It is
IIRC that's the drive used in the PortablePC and PCjr. In which case I'll
have the schematics for it. Hang on...
The index sensor on that drive goes into a schmitt trigger circuit using
U16 f and U16c ('LS14). The output of that goes to U10c ('38) and thence
tiooe the interface connector. TP7 is the index testpoint.
There's no monostable, or filtering, or anytthing like that on this drive.
Some drives, particularly 3.5" ones, have an adjustable monostable in the
index circuit which lets you delay the index pulse. It's adjusted when
the drive is aloighed to give the correct timing between the index pulse
and the data ffrom the ehad -- twiddlign the pot is easier than moving
the index sensor. Such a circuit could msess up what you're trying to do,
but this IBM drive doesn't have anything like that.
> good to work on because it is all descrete parts and
> TTL ( some analog IC's as well ). Still, if they have a
> filter on the index, I should be able to modify it.
> I only see one pot in that area of the board and I suspect
> that it is for the pulse witdh of the index.
I can find 2 pots on the schrmatic. R56 (connected ot U1, an LM2917),
sets the spidnle motor speed. R63, connectrd to U2 (MC3740) is the common
read-data balance adjustment.
-tony
Date: Mon, 24 Dec 2007 01:20:15 -0000
From: "Ensor" <classiccmp at memory-alpha.org.uk>
Subject: Re: Yet another VT-100 emulator
<snip>
>But like everyone else, you've missed the point. The OP was originally
>asking about standard IBM cards, not about VESA "standard" cards which are a
>different kettly of fish....
>TTFN - Pete.
------------
Actually, I think *you*'re missing the point of this whole thread, which is the
feasibility of 132 column mode in Dave's VT-100 emulator; FYI I'll quote the OP:
...
"Does anyone know if any of the more modern (ie: VGA) cards support enhanced
132 column text modes? - And is the video addressing basically the same except
for 132 words of memory per line instead of 80? And where to find more information?
If it could be reliably determined that support was there, and it is compatible with
my text windowing code, it would not be difficult to add support for it."
...
m
One last try, this stuff is going to start getting junked at the end of this
week unless someone pipes up:
--Monitors--
SGI 19" Colour Monitor (white in colour, unknown model #)
Philips MDA/Hercules Monitor
--Terminals--
Televideo 950 (*2, spares or repair)
Wyse 30
Zenith Z89 (spares or repair)
--Computers--
Power Macintosh (Dunno model # offhand)
BBC Micro (*2)
CBM PET (at least 3, plus floppy drive units)
Tandon PAC-286 (c/w kbd, monitor, printer)
--Printers--
HP LaserJet+
IBM ProPrinter XL24 (unknown condition)
--Other--
Philips CDD-462 External CD-ROM drive
Odd stand alone NCR tape drive unit
Telexbox III (possibly *2)
BT Modem rack (contains some 10 14k modem cards)
Philips BSB Satellite Receiver (*3)
Tatung BSB Satellite Receiver
Panasonic Analogue Satellite Receiver
"Micro Decision" magazines from 1989/90
There's a reasonable amount of other stuff which I haven't been able to get
at to catalogue yet which will also be on offer.
Please contact me directly at "ensor" at the domain name this message came
>from for more details or if you're interested in any of this stuff as I'll
be quitting the list over the next couple of days.
TTFN - Pete.
>> But like everyone else, you've missed the point....
> That must be why didn't add VESA 132-column mode to his VT100
>emuatlor....
Which is something which came along sometime AFTER the original question was
posed, moron....
---------Original Message:
Date: Wed, 19 Dec 2007 01:37:08 -0000
From: "Ensor" <classiccmp at memory-alpha.org.uk>
Subject: Re: Yet another VT-100 emulator
Hi,
>>> Not likely - as far as I know there are no standard PC text
>>>video modes that give 132 columns.
>>
>> Long ago I had a 132char driver for the Hercules/TTL mono video
>>card. I was based on the 720x348 mono graphics mode.
>
> As far as I know there are no **STANDARD** PC text video modes
>that give 132 columns.
Precisely, just what is so difficult about that statement for people on this
list to understand!!??
The bottom line is that the **ONLY** ***STANDARD*** text modes supported by
EGA and VGA adapters are 40 and 80 column. END OF ARGUMENT. PERIOD.
Whilst it is perfectly true that most/all "SuperVGA" cards support one or
more 132 column text modes, these modes - along with their mode numbers -
are unique to each manufacturer and indeed often differ between chipsets
>from the same manufacturer!
Great if you want to tie your software to working with only a single brand
of chipset/graphics card (which I doubt is what the OP wants), but otherwise
utterly useless....
<snip>
The OP needs modes which work on ALL adapters, not non-standard modes which
work on a small number of Mickey Mouse cards which noone uses....
TTFN - Pete.
---------Reply:
VESA will be disappointed to hear that their VBE standard which does define four
132-column modes (109 - 10C) is not a "standard" at all (insofar as anything in this
field can be considered "standard.")
http://en.wikipedia.org/wiki/VESA_BIOS_Extensions
I'd say a Mickey Mouse card is one that does *not* implement the VESA extensions,
and I think there's more than just one brand that *does*...
But if you think we should all be restricted to EGA and VGA modes (who actually has
an EGA or VGA card and/or monitor?) then who am I to argue; I personally find 132
columns useful at times.
mike
From: ard at p850ug1.demon.co.uk
> The normal way to separate index form secotr pulses was to have a
> non-retriggerable monostable that was triggered from the index sensor and
> which had a period a little less than the time between sector holes. It
> was triggered at the end of each hole. Normally it timed out after each
> sector hole, but was still set when the index hole came after the last
> sectore hole. The output of said monostabel sent the output of the index
> hole sesnor to either the 'sector' line or the 'index' line.
The period of the monostable is pretty flexible--anything longer than
half the time between sectors and less than the time between sectors
will work. If you're "back of the envelope-ing" it, you might shoot
for 75% of the time between sectors. This would allow a pot-less
design, as the component tolerances would be well within the "slop"
allowed in timing.
> Some drives, particularly 3.5" ones, have an adjustable monostable in the
> index circuit which lets you delay the index pulse. It's adjusted when the
> drive is aloighed to give the correct timing between the index pulse and
> the data ffrom the ehad -- twiddlign the pot is easier than moving the
> index sensor. Such a circuit could msess up what you're trying to do, but
> this IBM drive doesn't have anything like that.
Most newer 3.5" drives subsume the "ready" circuit into a monolithic
hunk of silicon with the rest of the drive control. Index output
pulses are blocked until the period between indexes satisfies some
internal "ready" standard. Also, 3.5" drives can have *very* wide
index pulses when compared to 5.25" and 8" drives.
Of course, any 5.25" drive with this logic (and it's very common)
will view a hard-sector disk as not being anywhere near the correct
speed, so will not only not come ready, but will block *all* index
pulses going out.
This feature has a curious implication if you decide to replace an
older drive without the "block index until ready" logic with a newer
drive with that logic. Many controllers (such as the WD1770) or
software will count up a few sectors after select or motor on before
commencing an operation. The result is that everything still works,
but the latency after selecting a drive increases significantly.
Note that once the drive been selected and come ready, this is not an
issue.
For what it's worth,
Chuck