< >Reason:
< >
< >Components, IC's and especially those SMD's and quads are very hard
< >to clean to assure reliablity.
< >
< >Cigerette smoke film are sticky and conductive to some degree!
< >
While isopropanol is good wash a trip through the dish washer works every
time for me. Air dry or a cool oven to get out any trapped water.
Did that on a trs80 that was megga nasty once and it came out better than
factory. Keyboard and all.
Water and detergent is safe for most everything.
allison
At 10:06 PM 9/21/98 -0700, you wrote:
>is better than that stuff you get from the hardware store called "Goo-off"
>or what not. Also, enough rubbing alcohol will take just about anything
>off.
Be carefull using isopropyl or rubbing alcohol, I've found it discolors a
lot of paints and plastics. I've found that denatured alcohol is safer.
Joe
Zane asked:
>However, I just realized, I am trying to make this overly difficult. I'm
>wanting to use these drives on PDP-11's which means they need to be
>formated on one. So the question I should really be asking is how to get
>them formated on a RQDX3 that's in a PDP-11. The reason for trying to
>format them on the VS2000 was just to make sure they worked (and for some
>reason I was thinking it was a good idea, go figure).
The VS2000 low-level format will be compatible with the RQDX3. (The
VS2000 format isn't compatible with the RQDX1/2, though.)
Megan suggested:
>Then what you want is the XXDP+ kit, and the ZRQC formatter.
The ZRQC?? formatter will do the trick, too, but the VS2000 formatter
is far more convenient and robust. I keep a VS2000 around for no
other purpose than formatting MFM disks when I have to. Suggesting
that someone use ZRQC?? when they have a VS2000 available is like
suggesting that they learn how to fly an airplane rather than simply
using an airline ticket :-).
Zane asked about ZRQC??:
>So what does it want for input? Don't know if this is a stupid question,
>but am asking since I've never actually used XXDP+ and I didn't get any
>documentation at all with the Packs, despite the fact that the rest had
>related Docs.
I'd go the VS2000 route myself, but if you insist on XXDP+ I can
fax you a couple pages out of the MicroPDP technical manuals that
will get you started. If you thought the VS2000 prompts were
cryptic, you've never seen the ZRQC?? prompts :-).
Also, since nobody else has mentioned it, *none* of this stuff is any
great secret. A lot of this is very well explained in Terry Kennedy's
collection of DECUSERVE conferences, THIRD-PARTY-DISKS.TXT, available
by anonymous ftp from ftp.spc.edu.
--
Tim Shoppa Email: shoppa(a)trailing-edge.com
Trailing Edge Technology Voice: 301-767-5917
7328 Bradley Blvd Fax: 301-767-5927
Bethesda, MD, USA 20817
I got a bunch of Q-Bus and Unibus boards today, most of which are DEC, and
most of which I was able to identify. One really caught my eye that I
can't identify however.
It's a Quad-Height board with a 50-pin connector on it There is one chip
with a Model number on it "UTS25". The board looks to be manufactured by
either MTI or MT, not sure which. The one EPROM says "MTI-U/B A3.4". It
has a Z80B CPU from SGS, and a Zilog Z0853606PSC chip. However the chip
that really caught my eye was a WD33C93-PL. Could this be a fabled SCSI
controller? The WD chip is the same as an Amiga 3000's SCSI controller.
Zane
| Zane H. Healy | UNIX Systems Adminstrator |
| healyzh(a)ix.netcom.com (primary) | Linux Enthusiast |
| healyzh(a)holonet.net (alternate) | Classic Computer Collector |
+----------------------------------+----------------------------+
| Empire of the Petal Throne and Traveller Role Playing, |
| and Zane's Computer Museum. |
| http://www.dragonfire.net/~healyzh/ |
< ----- Transcript of session follows -----
< ... while talking to po.laidbak.com.:
< >>> MAIL From:<allisonp(a)world.std.com>
< <<< 550 Access denied
< 554 <nerdware(a)laidbak.com>... Service unavailable
It's near impossible to discuss anything of your mailer is misconfigured
or broken. Real address?
Allison
In a message dated 98-09-22 04:56:58 EDT, you write:
<< I'm appalled at what some collectors collect. >>
I suspect that the Shoe collectors would be appalled at what you collect. It
is this diversity of people that make the world interesting. I am attracted to
the idea of collecting mainframes, my signifigant other is appalled at that
attraction. I had a Litton 1251 in my living room when we met 19 years ago. I
mention this so we would be on topic for the list. 400K of drum memory, a
very interesting machine.
Paxton
There is a Shoe phone out there in the marketplace, I have seen one. The shoe
phone is over 10 years old so It is not too far off topic.
The population of collectors is growing by leaps and bounds. The internet
revolution is making it much easier to get together and form community. I too
am amazed at what collectors collect.
Paxton
THrowing in my $0.02 here...
At 09:07 PM 9/18/98 -0700, Sam wrote:
>
>Ok, so I have a 15W bulb in series with the P/S and it lit up. The fan
>didn't start blowing until the second time I powered up, but its blowing,
>albeit very slowly due to the limited power I assume.
When its powered down, give the fan a spin with your finger. It should
spin freely. If not, it should be replaced. The older bronze/oilite
bearings dried out and would start to stiffen up after a souple of years of
operation.
>I didn't go the full Tony route because doing so would've required
>desoldering the entire transformer which wasn't an attractive prospect.
True 'nuff... Unless you got a very early IMSAI with the point-to-point
wires PS.
>I measured the voltages across a power connector and got 9.4V, +17.56 and
>-17.86. A little high but I attribute that to a lack of a load.
That is actually pretty much normal. Keeping in mind that the mains on the
S-100 bus are unregulated and spec'd (such as it is) at +8 and +/-16VDC to
allow for drop under load without falling out of the 'comfort' range for
the regulators on the individual boards.
>At this point I feel pretty comfortable that the P/S is working pretty
>well, which surprised me. I expected a fight (but was hoping for the
>results I got). These old machines just refuse to die.
The big 'can' caps are a good deal harder to kill than the minis...
>I'm going to let it warm up for about an hour before I start plugging in
>boards.
Never can be too safe. In the case of my PDP-8/i which had not been fired
in a known 10+ years, once I had the supplied spun up I ran it in under
(auto) lamp loads for a little over 6 hours (frequently checking for ripple
with a 'scope) before I started reconnecting logic.
But thats just me... B^}
So... 'fess up. Is this the 'door prize' IMSAI?
-jim
---
jimw(a)agora.rdrop.com
The Computer Garage - http://www.rdrop.com/~jimw
Computer Garage Fax - (503) 646-0174
>Not a silly question in the least. Sort of falls in the "now why didn't I
>think of that" catagory! In all cases except 1 DS1 was jumpered, on the
>one exception, nothing is jumpered. Set it to DS2, no luck, set it to DS3
>and it works. Thanks!
This falls into the category of "my 11/73's line time clock quit
working" :-). *Extremely* common problem, extremely simple answer!
>Next question, does anyone happen to have the list of correct answers to
>give the formating program written down anywhere? Yes, I'm lazy enough not
>to want to have to figure that out.
Roger Ivie posted the following many, many years ago. It's for the RD51,
not the RD52, but it should get you started. One tiny note: Roger
didn't figure out the Media ID scheme, but if you look at the source
code to my DUSTAT utility (i.e. take a look at:
http://sunsite.unc.edu/pub/academic/computer-science/history/pdp-11/rt/dust…
) and look at my comments there about how the media type code is
represented.
--
Tim Shoppa Email: shoppa(a)trailing-edge.com
Trailing Edge Technology Voice: 301-767-5917
7328 Bradley Blvd Fax: 301-767-5927
Bethesda, MD, USA 20817
I've come across the notes I used to format an RD51 (that's a 10MB disk,
folks) on a VS2000. When I was done, I was able to mount the disk under
VMS. Here's what my notes say:
An XBN is a block containing geometry info for the drive.
DBNs are the blocks between the XBN and the end of the cylinder; essentially,
the first cylinder of the drive is reserved to contain geometry info, but
not all of the blocks in the cylinder may be used. DBNs fill out the
first cylinder after all the XBNs are filled in.
LBNs are blocks containing user data.
RBNs are replacement blocks.
RCTSIZ appears to be the size of the replacement block table in blocks, but
I have a ? after my note on that one.
RCTNBR appears to be the number of copies of the RCT on the disk, again I've
makred that with a ?.
Here were my answers to the questions for the RD51. The RD51 has 305 cylinders
and 4 heads. I'm pretty certain the VS2000 and RQDX3 use 17 sectors/track (the
RQDX2 used 18 sectors/track; reformatting a disk with an RQDX3 drops its
capacity slightly):
XBNSIZ: 54 I used 54 because all the info I've seen for other drives
used 54.
DBNSIZ: 14 A cylinder on the RD51 has 68 blocks. After the 54 XBN
blocks are allocated, 14 blocks are left in the cylinder.
LBNSIZ: 20000 I just winged this one. You should be able to twiddle this
up or down by playing with the replacement blocks.
RBNSIZ: 168 I think I picked this because that's what an RD52 uses, but
I don't remember.
SURPUN: 4 The RD51 has four heads.
CYLPUN: 305 The RD51 has 305 cylinders.
WRTPRC: 305 I don't remember where write precomp is supposed to be turned
on for the RD51, so I turned it off for the whole drive. This
should be the cylinder number where write precomp starts.
RCTSIZ: 4 Again, taken from the RD52
RCTNBR: 8 Again, taken from the RD52
SECITL: 1 Sectors should be number 1 through 17 instead of 0 through 16.
STSSKW: 2 Head-to-head skew in sectors. The RD52 also uses 2.
CTCSKW: 14 Cylinder-to-cylinder skew in sectors. I don't remember why I
picked 14; some experimentation should let you figure out what
to use here.
MEDIAI: 627327027 I'm pretty sure I looked in the source listings to see what
the driver was expecting for an RD51. Short of doing that,
I don't know what else to do here. I don't know if this
number is really critical for antyhing; the driver should use
the XBNs to get the geometry information instead of depending
on the media ID to look it up.
