Cathode poisoning in nixies is caused by them being left on the same
digit for a long time, usually days or months. Consistently running them
on the same digit (first digit in a 12-hour clock, first digits on a
frequency counter that doesn't blank unused digits) will also cause
relative darkening of the adjacent cathodes, and occasionally some
sputter will actually cause an internal short circuit which may or may
not ultimately destroy the tube. Multiplexing should extend the life of
the tubes. Running nixies at less than their rated current will increase
their lifespan, and running them over-current for shorter periods will
often rejuvenate them.
Regards,
Micah Mabelitini
Your OS depends on the keyboard. HP 400s were the "hybrid" models made
after HP acquired Apollo, so from the factory they were set up to run
either HP-UX (9 or earlier) with a HP-HIL keyboard or mouse, or
DOMAIN/os (Aegis) with a Domain keyboard. Switching between the two
requires keyboard/mouse swap and setting one value in the NVRAM.
I've only used DOMAIN on my 425, since HP-UX of the early '90s has been
described as not spectacular. SR10.4 works well, and with the y1k997
patches it seems to tick along just fine in the 21st century. DOMAIN is
neat since it's so network-transparent and very unusual, but with the
BSD or SysV environments the learning curve is not nearly as big as
with the Aegis environment.
Of course, NetBSD can be run on them with a HP-HIL keyboard setup as
well, but I think it's pretty evident which camp I'm in. Bear has some
manuals on his site (www.typewritten.org)
Scott
thanks Richard!
> Takes anything after the first space on the line to be a
> description of the file. These haven't been added to the .txt
> file for some time, but if they're there, I'll pick them up.
If someone wants to add the descriptions, that would be great. I should
do it when I add the entries, but..
Has anyone considered teaming up with someone who makes neon signs to make
a nixie tube?
--
David Griffith
dgriffi at cs.csubak.edu
A: Because it fouls the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?
I don't know about cases but I do remember a TV program where an IBM guy
reached into a drawer and produced the first and original wire wrapped
8088 PC prototype board. Talk about 'mother of many'!!
Rod Smallwood
-----Original Message-----
From: cctech-bounces at classiccmp.org
[mailto:cctech-bounces at classiccmp.org] On Behalf Of Fred Cisin
Sent: 05 March 2007 20:44
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: place your bets
> > Did the earliest prototypes of the PC, and later AT, that Microsoft
> > got to work with have cases?
>
On Mon, 5 Mar 2007, Chris M wrote:
> Whether that question is rhetorical or not, I haven't the answer. Are
> there pictures of these things somewhere out there?
not rhetorical
(Don't you hate rhetorical questions?)
There don't seem to be pictures, and the people are getting scarcer.
I had a friend who worked at Microsoft in those days (and before, when
you could ask for somebody on the phone by first name), but he died a
few years ago.
>
>Subject: Re: Copying DEC VAX set up disks rx50, help
> From: "Dave Dunfield" <dave06a at dunfield.com>
> Date: Sun, 04 Mar 2007 07:00:53 -0500
> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
>
>> Image Disk reads it with out errors
>> 0/0: 300k DD 10 sectors of 512 bytes - G1:9 G2:17
>> 0/1: Single sided
>> 0/0: Single Step
>> 800 sectors (800 data, 0 compressed, 0 unaval)
>> Read complete
>>
>>
>> Trying to write and it has errors from the get go.
>> 0/0: 300k 10 sectors of 512 bytes
>> :format error <0> overun
>> :write error <2> no sector
>> and on .............................
>>
>> written on a PC with 1.2 HD drive
>> Tried on another 1.2 and on a 360k drive
>> all capable of SD .
>>
>> I tried both HD and DD disks . all bulk erased first.
>
>Don't use HD disks - as ImageDisk noted in it's initial
>report, all sectors in the image are double-density.
To affirm this, as exDEC RX50 is DD (250kbs).
>You didn't show all the information, but since it's
>single-sided, 10 sectors per track, and there are 800
>sectors, this tells me it's an 80 track disk.
>
>So - don't use a 360K drive (they are only 40 tracks).
>You shouldn't need to worry about SD capability - there
>are no SD sectors in the image.
Correct The RX50 drive is a dual spindle single head
positioner 80 track (96tpi) drive.
>The 300k data rate tells me that you recorded this on a
>1.2M HD drive - I'm assuming you did not specify a 300-250k
>data rate translation when you recorded it (?)
It's not 300 data rate it's 250!
>Assuming all that, it should write back to a 1.2M HD drive
>with ImageDisk. It should also write back to a 80 track DD
>drive such as TEAC-55F or SA-460 or TM-100-4. You would need
>to set a 250->300k data rate translation to write on a DD drive.
>
>I don't have any VAX disks to try, however I have read and
>written Rainbow disks, which are also RX50 and use 80 tracks
>by 10x512byte sectors, so I know ImageDisk works with this
>format.
VAX, Rainbow and otehr DEC RX50 media are all the same save for
the filesystems. The only other DEC 5.25 formats are RX180 (Robin
aka VT180 which is 40 track single sided DD 180k) and Vaxmate
(286 PC like) that used the RX33 drive for standard PC 1.2mb
format.
There is a VAX RX33 format that was found in microVAX2000 or
RQDX3 controller for QBUS systems [must be late firmware on
the MSCP sontroller]. That format was a flavor of 1.2mb PC
format and also did RX50 using FD55GFR (aka RX33 drive). Older
firmware RQDX-1/2/3 controller only did RX50 format.
>10x512byte sectors can be twitchy on some PC setups. It
>pushes the limits of the drive and formatting more than
>the standard PC formats do. Most systems which use 10x512
>have a more flexible FDC than the PC does.
>
>Some suggestions:
>
>- Clean the heads and make sure the drive is working OK.
> Format a floppy on your PC, then read it with ImageDisk
> and see if all sectors can be written.
>
>** Don't bother looking at any other suggestions until your
>** drive is verified to be operating 100%
>
>- Make sure you are using a recent copy of ImageDisk (you
> can get the latest from my site). Some of the older
> versions had trouble with gap calculations, especially
> on "tighter" disks.
>
>- Try another PC (not just a different drive).
Important as PC controler vary in implmentation at the subtle level.
>- Try making one of the Rainbow images from my site - this
> is the same format.
> NOTE: My images reflect the true data rate of the target
> system (250k), so you will need to set a 250->300k
> data rate translation to write them on an HD drive.
> If this works, then there may be a problem with the
> imaes you have created - send me one to look at.
>
>- Check your drive speed. If it's high, try slowing it to
> exactly 360 rpm - if it's "bang on", you might try slowing
> it by 5-10 rpm - this can help if your PC is marginal at
> the gaps required for 10x512.
This works and can help greatly.
Also make sure the PC is trying to run the 1.2mb drive at 300rpm
and NOT 360 or switching to 300kbs while using the nominal 360rpm
as NEITHER WILL WORK. RX50 is NOT 1.2mb mode its a 80track flavor
of DD (400k per disk single sided). This is a foreign format
and requires forcing the PC hardware in many cases. I cheat
I use a FD55E (96tpi, single sided 360rpm only) as then the PC
cannot force 300 rpm.
>- Look at the calculated gap sizes, and try reducing them
> slightly. You shouldn't need to, but it's worth a try - PCs
> are "highly variable".
;) you got that one nailed.
>I don't have VAX disks to try, but I've just successfully made
>one of my Rainbow images using ImageDisk 1.14 and a HD drive.
>The speed test shows my drive at 359 rpm.
Rainbow RX50 and VAX RX50 are same on disk low level format.
The filesystems are very different but if your reading sectors
(raw) then they are identical. I may add that XXDP(x11 diags)
on RX50 and RT-11 on RX50 also share that common media level
format.
In DEC parlance RX50 refers to 80tracks, 96tpi, single sided
with 10 sectors per track and 512bytes persector formatted
at a data rate of 250kbs @360 rpm. It also refers to the drive
known as RX50.
Hole this clears up some misconceptions.
Allison
> Will we be able to see the listing of those cards you just won from
> NASA? :-)
I'm assuming they are binaries for the IBM 704, since they are described
as 704 column binary.
the auction was
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=330095278250
> After a recent fight with some Cipher tape drives,
> trying to boot a system, I managed to badly mangle the
> leader of my boot tape.
> The BOT on a nine track is
> just a hunk of sensing foil
True, but on tapes 1600 bpi and higher there is a burst
recorded over the BOT marker on one of the tracks to identify
the density. You obviously can't move the mark very far into
the tape without running into the first data block either, even
if you force the read density, which you can't really do on auto
loading Ciphers.
I have spliced new leader onto damaged tape before, using
analog tape splicing techniques (diagonal cut with two overlapping
pieces, then tape on the back). From memory, Cipher drives don't
have flux gates (little door over the top of the head). Thin clear
packing tape works OK, but don't plan on reusing the tape after you
get the data off.
>
>Subject: Re: Copying DEC VAX set up disks rx50, help
> From: ard at p850ug1.demon.co.uk (Tony Duell)
> Date: Sun, 04 Mar 2007 03:00:37 +0000 (GMT)
> To: cctalk at classiccmp.org
>
>> I dunno, RX50 format is easy to copy. Make sure that your 1.2M drive
>> is declared as such in the BIOS setup--if it's confused with a 1.44MB
>> drive, it's not going to work, as 2D operation on a 1.2MB requires a
>> write clock (300KHz) that conforms to a 360 RPM drive. A 1.44MB
>> drive is 300 RPM--so any attempt to write a 2D format using a 250KHz
>> clock rate is guaranteed to fail--you'll run out track before you run
>> out of data.
>
>I once saw a PC multi-I/O card that couldn't do the 300kbps data rate, I
>think it just did it as 250kbps.... Needless to say that card went
>straight back to the suppliers...
>
>Anyway, with so few people (other than on this list :-)) using 5.25"
>drives now, I wonder if most modern PCs can still generate the 300kbps
>rate, If not, this could explain the problems the OP is having...
>
>-tony
Wrong. The RX50 format and RX33 formats are very differnt. The RX33
is PC compatable and was not used for VMS floppy sets. The RX50 drive
is a Single sided 80 track (96tpi) double density drive with the oddity
of two spindles and one head positioner. I have used FD55F as a single
drive repelacement as RX50s are not very reliable and noisy (acousticlly).
The RX33 drive (FD55GFR or similar) in the slow mode also works fine.
The problem is to fit 10sectors DEC used the WD1793 and fudged the format
some to truncate the Index mark gap and end of track gap.
The 765 will read this if: it is the 765A or 7265 and the drive is not
running fast (works better if running 1% slow!). The 765 has a built in
ship over index time and the later versions had this time shortend or
eliminated in the case of the 7265. The easy fix is slow the drive a
few percent till it starts reading. The hard way fix is to crank up the
clock driving the 765by 2% (replace the 8/16/24or 32mhz clock with
one 2% faster). It's harder as finding a clock that is just a tad faster
is not common. FYI: some PC floppy controller work better than others
due to implmentation differnces internal to the integrated flavors of the
765 (9266, 8243, 37C65m 37C665...).
Me I cheat, I use either the PDP11 or a real microVAX with RX50 or rx33
and avoid the pain.
Allison
