wanted: TI Silent 700 Model 763 & 765 Maintenance Manual

[Eric Smith]

Does anyone have that?

The manual for Model 743 & 745 is on Bitsavers, but I'm specifically
looking for model 763 & 765.

Re: Power cable identification

[dwight]

Might also try

http://www.alliedelec.com/alpha-wire-543-bk078/70125977/?utm_source=octopart_medium=part_sourcing_campaign=octopart

[http://www.alliedelec.com/images/products/Small/70125977.jpg]

Alpha Wire - 543 BK078 - Black C13 connector NEMA 5-15 
...
www.alliedelec.com
543 BK078 from Alpha Wire at Allied Electronics ... Application: For business 
machines, point-of-sale terminals, computers and peripheral equipment, OEM 
equipment





From: cctalk  on behalf of dwight 

Sent: Saturday, June 25, 2016 9:06:39 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Power cable identification

You might try these guys.

http://www.sphere.bc.ca/test/hp1.html


HP Used Electronic Test Equipment - 
Sphere
www.sphere.bc.ca
Great deals in HP Used Electronic Test Equipment and Parts: Welcome To Sphere 
Research's Canadian Test Equipment & Parts Site! This Section Updated Weekly





From: cctalk  on behalf of Mike Ross 

Sent: Saturday, June 25, 2016 9:01:30 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Power cable identification

On Jun 26, 2016 3:12 PM, "Glen Slick"  wrote:
>
> On Sat, Jun 25, 2016 at 8:09 PM, Josh Dersch  wrote:
> > So I know for certain that this topic has come up before, but I cannot
for
> > the life of me find the thread(s) it appeared in, so I'm asking again
> > (apologies in advance).
> >
> > What is the name of the rounded, 3-pin power connector often seen on
early
> > test equipment (I've seen it on older HP and Fluke stuff)?  I have an
S-100
> > chassis that inexplicably uses one, despite dating from 1982 or so.  I
need
> > to track one of these cables down but I have no idea what it is exactly
I'm
> > looking for...
>
> Round or oval?
>
> Maybe a 163 as shown on Brent's page here:
> http://www.cs.ubc.ca/~hilpert/e/powerConn/index.html#163

Ahh.

The place I always think of those is on IBM 3278 terminals.

Mike

Re: Power cable identification

[dwight]

You might try these guys.

http://www.sphere.bc.ca/test/hp1.html


HP Used Electronic Test Equipment - 
Sphere
www.sphere.bc.ca
Great deals in HP Used Electronic Test Equipment and Parts: Welcome To Sphere 
Research's Canadian Test Equipment & Parts Site! This Section Updated Weekly





From: cctalk  on behalf of Mike Ross 

Sent: Saturday, June 25, 2016 9:01:30 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Power cable identification

On Jun 26, 2016 3:12 PM, "Glen Slick"  wrote:
>
> On Sat, Jun 25, 2016 at 8:09 PM, Josh Dersch  wrote:
> > So I know for certain that this topic has come up before, but I cannot
for
> > the life of me find the thread(s) it appeared in, so I'm asking again
> > (apologies in advance).
> >
> > What is the name of the rounded, 3-pin power connector often seen on
early
> > test equipment (I've seen it on older HP and Fluke stuff)?  I have an
S-100
> > chassis that inexplicably uses one, despite dating from 1982 or so.  I
need
> > to track one of these cables down but I have no idea what it is exactly
I'm
> > looking for...
>
> Round or oval?
>
> Maybe a 163 as shown on Brent's page here:
> http://www.cs.ubc.ca/~hilpert/e/powerConn/index.html#163

Ahh.

The place I always think of those is on IBM 3278 terminals.

Mike

Re: Power cable identification

[Mark J. Blair]

> On Jun 25, 2016, at 20:12, William Donzelli  wrote:
> 
>> What is the name of the rounded, 3-pin power connector often seen on early
>> test equipment (I've seen it on older HP and Fluke stuff)?  I have an S-100
>> chassis that inexplicably uses one, despite dating from 1982 or so.  I need
>> to track one of these cables down but I have no idea what it is exactly I'm
>> looking for...
> 
> The trade name is 163.

I seem to recall encountering two different pinouts of that connector in 
equipment that has passed through my hands. My memory may be faulty, but I 
think that the ground lead was consistent but the hot/neutral were wired two 
different ways. Did I make this all up?

-- 
Mark J. Blair, NF6X 
http://www.nf6x.net/

Re: Power cable identification

[Josh Dersch]

On Sat, Jun 25, 2016 at 8:12 PM, Glen Slick  wrote:

> On Sat, Jun 25, 2016 at 8:09 PM, Josh Dersch  wrote:
> > So I know for certain that this topic has come up before, but I cannot
> for
> > the life of me find the thread(s) it appeared in, so I'm asking again
> > (apologies in advance).
> >
> > What is the name of the rounded, 3-pin power connector often seen on
> early
> > test equipment (I've seen it on older HP and Fluke stuff)?  I have an
> S-100
> > chassis that inexplicably uses one, despite dating from 1982 or so.  I
> need
> > to track one of these cables down but I have no idea what it is exactly
> I'm
> > looking for...
>
> Round or oval?
>
> Maybe a 163 as shown on Brent's page here:
> http://www.cs.ubc.ca/~hilpert/e/powerConn/index.html#163
>


Thanks (also thanks to William).  The 163's the one I'm looking for.  That
was quick! :)

- Josh

Re: Power cable identification

[Glen Slick]

On Sat, Jun 25, 2016 at 8:09 PM, Josh Dersch  wrote:
> So I know for certain that this topic has come up before, but I cannot for
> the life of me find the thread(s) it appeared in, so I'm asking again
> (apologies in advance).
>
> What is the name of the rounded, 3-pin power connector often seen on early
> test equipment (I've seen it on older HP and Fluke stuff)?  I have an S-100
> chassis that inexplicably uses one, despite dating from 1982 or so.  I need
> to track one of these cables down but I have no idea what it is exactly I'm
> looking for...

Round or oval?

Maybe a 163 as shown on Brent's page here:
http://www.cs.ubc.ca/~hilpert/e/powerConn/index.html#163

Power cable identification

[Josh Dersch]

So I know for certain that this topic has come up before, but I cannot 
for the life of me find the thread(s) it appeared in, so I'm asking 
again (apologies in advance).


What is the name of the rounded, 3-pin power connector often seen on 
early test equipment (I've seen it on older HP and Fluke stuff)?  I have 
an S-100 chassis that inexplicably uses one, despite dating from 1982 or 
so.  I need to track one of these cables down but I have no idea what it 
is exactly I'm looking for...


Thanks as always,
Josh

Re: Y Combinator is restoring one of Alan Kay's Xerox Alto machines

[Curious Marc]

There are only two entries right now:

http://www.righto.com/2016/06/y-combinators-xerox-alto-restoring.html

http://www.righto.com/2016/06/restoring-y-combinators-xerox-alto-day.html

Marc

 

On 24 June 2016 at 10:05,   wrote:

And here is Ken's new post in the series

http://www.righto.com/2016/06/restoring-y-combinators-xerox-alto-day.html

 

 

I can't see any dates on the post, but I am not seeing a new one there...

 

-- 

Liam Proven 

 

Re: Pictures from the GA warehouse, take 2...

[John H. Reinhardt]

 Glen Slick wrote:

On Sat, Jun 25, 2016 at 2:32 PM, Todd Killingsworth
 wrote:

Ok gang - here's the 100+ pics from the warehouse:

https://www.flickr.com/gp/16985@N04/b76872



For DEC gear some of what I see are at least one or multiple of:

AlphaServer 800
AlphaServer 1000A
DECstation 3100
DECstation 5000/200
DECstation 5000/240
VAXstation 4000/60
VAXstation 3100/M48
MicroVAX 3800
VT510
desktop Storage Expansion boxes

If I was local I might grab a VAXstation 4000/60, MicroVAX 3800, VT510.



I'm in Cincinnati so not that far away. I'd like a VAXstation 4000/60, a 
storage expansion box and a VT510, but I'm not sure how my wife feels about it. 
;)  The MicroVAX 3800 would be nice, too.  But all of these are wants, not 
needs, and I can't take pallets of the stuff anyway. Wife would definitely put 
the hex on THAT! :-o

John H. Reinhardt

Re: Pictures from the GA warehouse, take 2...

[Paul Anderson]

pic 4938...la210?
  7973 vr241 or vt220s?
  4991lk201s?
  4997...face down, upper left, vr241?

On Sat, Jun 25, 2016 at 5:51 PM, Rob Jarratt 
wrote:

>
>
> > -Original Message-
> > From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Paul
> > Anderson
> > Sent: 25 June 2016 23:08
> > To: General Discussion: On-Topic and Off-Topic Posts
> > 
> > Subject: Re: Pictures from the GA warehouse, take 2...
> >
> > I think i saw a VR241 in there.
> >
>
> I failed to spot that, and to think that this evening I have been working
> on my VR241!!
>
> Regards
>
> Rob
>
>

Re: Pictures from the GA warehouse, take 2...

[Todd Killingsworth]

HA! I missed that, and I took the picture!

Sent from my iPad

> On Jun 25, 2016, at 6:51 PM, Rob Jarratt  wrote:
> 
> 
> 
>> -Original Message-
>> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Paul
>> Anderson
>> Sent: 25 June 2016 23:08
>> To: General Discussion: On-Topic and Off-Topic Posts
>> 
>> Subject: Re: Pictures from the GA warehouse, take 2...
>> 
>> I think i saw a VR241 in there.
> 
> I failed to spot that, and to think that this evening I have been working on 
> my VR241!!
> 
> Regards
> 
> Rob
> 

RE: Pictures from the GA warehouse, take 2...

[Rob Jarratt]

> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Paul
> Anderson
> Sent: 25 June 2016 23:08
> To: General Discussion: On-Topic and Off-Topic Posts
> 
> Subject: Re: Pictures from the GA warehouse, take 2...
> 
> I think i saw a VR241 in there.
> 

I failed to spot that, and to think that this evening I have been working on my 
VR241!!

Regards

Rob

Re: Pictures from the GA warehouse, take 2...

[Nigel Williams]

On Sun, Jun 26, 2016 at 7:32 AM, Todd Killingsworth
 wrote:
> Terminals: DEC, IBM, Qume, AT, others

 A shout-out to the "others" category as there appears to be a
mountain of Unisys T0300 terminals there, quite a nice alternative to
the mainstream with several built-in emulations:

http://www.ebay.com/itm/Unisys-TO300-G-Terminal-/262072849895

Re: Pictures from the GA warehouse, take 2...

[Nigel Williams]

This is a chuckle:

https://www.flickr.com/photos/16985@N04/27810356761/in/album-72157670110346756/

A tub full of blue capacitors but also known as "caps", the tub is
labelled "VAULT MONEY", a reference to the game Fallout and the
monetised Bottle Caps?

Re: S/360 Model 30 (?) FS in NC

[William Donzelli]

Fall in line, Mike, fall in line...

--
Will
On Jun 25, 2016 6:00 PM, "Mike Ross"  wrote:

> What?! Where did you see this?
> On Jun 26, 2016 5:32 AM, "Noel Chiappa"  wrote:
>
> > Oooh, if I didn't have an _extremely_ strict rule about 'only PDP-11's'
> (to
> > prevent my house filling to the gills, and my wife divorcing me :-), I'd
> be
> > all over that. Someone definitely needs to grab this up!
> >
> > Noel
> >
>

Re: Pictures from the GA warehouse, take 2...

[Mike Ross]

On Sun, Jun 26, 2016 at 9:32 AM, Todd Killingsworth
 wrote:
> Ok gang - here's the 100+ pics from the warehouse:
>
> https://www.flickr.com/gp/16985@N04/b76872
>
> I included pics with model numbers where I could find them
>
> From what I could see:
>
> ** NO PDP or SGI anything (not even a coffee mug) **
>
> Commodore 64 with peripherals, pretty much new in box
> Sun E3000
> DEC VAX and Alpha desktop boxes
> DEC VAXServer 3800
> Three IBM mainframe peripherals of some sort

Those 'mainframe peripherals' are 3174 & 3274 terminal controllers.

Mike

http://www.corestore.org
'No greater love hath a man than he lay down his life for his brother.
Not for millions, not for glory, not for fame.
For one person, in the dark, where no one will ever know or see.'

Re: Pictures from the GA warehouse, take 2...

[Glen Slick]

On Sat, Jun 25, 2016 at 2:32 PM, Todd Killingsworth
 wrote:
> Ok gang - here's the 100+ pics from the warehouse:
>
> https://www.flickr.com/gp/16985@N04/b76872
>

For DEC gear some of what I see are at least one or multiple of:

AlphaServer 800
AlphaServer 1000A
DECstation 3100
DECstation 5000/200
DECstation 5000/240
VAXstation 4000/60
VAXstation 3100/M48
MicroVAX 3800
VT510
desktop Storage Expansion boxes

If I was local I might grab a VAXstation 4000/60, MicroVAX 3800, VT510.

Pictures from the GA warehouse, take 2...

[Todd Killingsworth]

Ok gang - here's the 100+ pics from the warehouse:

https://www.flickr.com/gp/16985@N04/b76872

I included pics with model numbers where I could find them

>From what I could see:

** NO PDP or SGI anything (not even a coffee mug) **

Commodore 64 with peripherals, pretty much new in box
Sun E3000
DEC VAX and Alpha desktop boxes
DEC VAXServer 3800
Three IBM mainframe peripherals of some sort
IBM robotic tape archiver
Terminals: DEC, IBM, Qume, AT, others
CRT displays
Printers: Okidata, etc

Keyboards:  lots of special IBM versions, listed below

8 pcs of the rare short Keyboard I described to you earlier.
Model F Keybds: I am not  sure how  many model F keyboards I have,
but I do have them.

~ 4 pcs of Original IBM PC and PC XT Keyboards (1981-1984)

IBM 5251 Keybds:  I have  approx 8 pcs of 5251  Keyboards.

Keyboards we have:
IBM 3151   104 ~20
IBM 3161   104 ~50
IBM 3162   104 ~25
IBM 3163   104 ~25
IBM 3164   104 ~50?
IBM 3178 ~100
IBM 3179 ~100
IBM 3180  122  ~150?
IBM 3191 ~100?
IBM 3192  122 & 104   ~100?
IBM 3193  Unkown Qty yet ?
IBM 3194  Unkown Qty yet ?
IBM 3196  122 & 104 ~75 pcs of 104
IBM 3197  122 & 104 ~75 pcs of 104
IBM 5155  Unkown Qty yet ?
IBM PC XT/AT   Unkown Qty yet ?
IBM 3471  122 & 104 ~75 pcs of 104   Sm qty of 122
IBM 3472  122 & 104 ~75 pcs of 104   Sm qty of 122
IBM 3476  122 & 104 ~75 pcs of 104   Sm qty of 122
IBM 3477  122 & 104 ~75 pcs of 104   Sm qty of 122
IBM 3481  122 & 104 ~75 pcs of 104   Sm qty of 122
IBM 3482  122 & 104 ~75 pcs of 104   Sm qty of 122
IBM 3483  122 & 104 ~75 pcs of 104   Sm qty of 122
IBM 3486  122 & 104 ~75 pcs of 104   Sm qty of 122
IBM 3487  122 & 104 ~75 pcs of 104   Sm qty of 122
IBM 3488   122 & 104~75 pcs of 104   Sm qty of 122
IBM 3489   122 & 104~75 pcs of 104   Sm qty of 122

Here are detailed part numbers:  (we probably have other models not
listed!!)

1368193
1386304
1386887
13901233191/3192
13902383191/3192
13905723196/3197
13905723196/3197
13907023191
13907023192
13908763196/3197
13908763196/3197
1391401Clicky Vintage
1392595
1394099
13941003471, 3472, 3481, 3482 3483  122-Key
13941673476, 3477, 3486, 3487  122-Key
1394193
13942043472  104-Key
1394204
1394802
1394806
1395162
13956603476, 3477, 3486, 3487  122-Key
13956653476, 3477, 3486, 3487  104-Key
1395666
6110668 3180?
6115543 3180?

Qty 1  IBM 5642852 for the IBM 5291-1 (the -1 is the rare one)
 Manufactured 1991-1993

Re: Y Combinator is restoring one of Alan Kay's Xerox Alto machines

[Curious Marc]

New video from yesterday’s work.

https://youtu.be/MDKxOmVDapQ

Ken will probably post a much more detailed article later.

Marc

 

From: cctalk  on behalf of "a...@bitsavers.org" 

Reply-To: "cctalk@classiccmp.org" 
Date: Monday, June 20, 2016 at 8:51 AM
To: "cctalk@classiccmp.org" 
Subject: Re: Y Combinator is restoring one of Alan Kay's Xerox Alto machines

 

I post just went up on Saturday. It's nice that both CHM and LCM folks

are helping with this.

 

 

On 6/20/16 8:41 AM, Liam Proven wrote:

http://www.righto.com/2016/06/y-combinators-xerox-alto-restoring.html

Found via:

http://www.osnews.com/story/29261/Xerox_Alto_restoring_the_legendary_1970s_GUI_computer

There are 2 videos up so far, with disassemblies that may interest CCmpers.

Some people from the list are involved, including Al Kossow, but I

haven't seen the link posted.

 

 

Re: S/360 Model 30 (?) FS in NC

[Mark J. Blair]

This reminds me: I wonder if anybody picked up that System/32 that was up for 
sale at a recycler near me several months ago? I hope it didn't take another 
spin around the aluminum cycle.



-- 
Mark J. Blair, NF6X 
http://www.nf6x.net/

Re: S/360 Model 30 (?) FS in NC

[COURYHOUSE]

I still have the aluminum bar that   says  360 30 that was  on the  top of 
the  system here in phx. I bought early on in my   computer business  life 
segment.
 
Aside  from being  part of a memento  for me   and  sort of interesting   
sitting in a glass case... it may need to   find its  way  back atop a  
360/30 someday.
 
Ed#   _www.smecc.org_ (http://www.smecc.org)  
 
 
In a message dated 6/25/2016 10:57:07 A.M. US Mountain Standard Time,  
a...@bitsavers.org writes:

Maybe a  2841 disk controller, but the 360/30 panel has been pulled. Hard 
to say what  is really there.
LCM may be interested in parts for their 360/30, and Will  Donzelli has 
been looking for a 2841


On 6/25/16 10:06 AM, Chuck  Guzis wrote:
>  
http://www.vcfed.org/forum/showthread.php?53014-IBM-360-with-additional-era-equipment
>  
> --Chuck
>  -
> 
>  "The first thing we do, let's kill all the spammers."
>  

Re: S/360 Model 30 (?) FS in NC

[Al Kossow]

Maybe a 2841 disk controller, but the 360/30 panel has been pulled. Hard to say 
what is really there.
LCM may be interested in parts for their 360/30, and Will Donzelli has been 
looking for a 2841


On 6/25/16 10:06 AM, Chuck Guzis wrote:
> http://www.vcfed.org/forum/showthread.php?53014-IBM-360-with-additional-era-equipment
> 
> --Chuck
> -
> 
> "The first thing we do, let's kill all the spammers."
> 

S/360 Model 30 (?) FS in NC

[Noel Chiappa]

Oooh, if I didn't have an _extremely_ strict rule about 'only PDP-11's' (to
prevent my house filling to the gills, and my wife divorcing me :-), I'd be
all over that. Someone definitely needs to grab this up!

Noel

S/360 Model 30 (?) FS in NC

[Chuck Guzis]

http://www.vcfed.org/forum/showthread.php?53014-IBM-360-with-additional-era-equipment

--Chuck
-

"The first thing we do, let's kill all the spammers."

Re: ACARD ARS-2000SUP versus SCSI2SD - round 1

[Swift Griggs]

On Sat, 25 Jun 2016, pete wrote:
> > I'd love to see results under IRIX, as I was thinking of trying one or both
> > of those myself!
> Seconded, though it looks like it'll be considerably slower than a real SCSI2
> hard drive.

I'm not sure about that. I've got another ACARD unit (the faster SCA 
model) that I use in my Tezro. I also have a second disk (the Tezro can 
hold a couple) that's a spinning rust 15k Barracuda. I don't have numbers 
right now (next time I fire up my Tezro I'll get some). However, 
anecdotally, the ACARD disk (also predicated on a Samsung 850 Pro SATA 
SSD) will absolutely stomp the Barracuda's guts out in every stat and 
especially on latency. 

The main time I can "feel" it is when I run Photoshop or a browser. The 
SSD-based ACARD makes the system feel a lot faster. Pages finish loading 
faster, 'rqsall' takes about half as long, packages install much more 
quickly, and the silly delays you get when 'inst' is reading package 
metadata takes a lot less time. I curse at it only about half as much (I 
love IRIX but 'inst' and I aren't pals - I haze it often).

I know that's all anecdotal, but I'm pretty sure I tested the disk when I 
first got it and it blew the rust-based drive away. I've just got my bench 
all covered with Quadra 700 parts and various jury-rigged SCSI cables so I 
can install from CDROM on a machine that doesn't have space for a CDROM 
etc.. When I finish refurbing this thing with a MacOS + A/UX 3 dual boot 
rig, I'll grab the SGIs. I'll try out the ACARD vs SCSI2SD on my R5k/180 
Indy.

-Swift

Re: Current source for RX50 media?

[Chuck Guzis]

On 06/24/2016 09:13 PM, Fred Cisin wrote:

> There are a couple of potential complications to using a 1.2M drive, 
> that can be gotten around in software. (96tpi track spacing, same
> write current, rotational speed and data transfer rate as for 360K)

IBM-style PCs with 1.2M drives use a 300Kbit/sec transfer rate for
double-density floppies.  A tool such as Dave Dunfield's IMD will work
just fine.   The last time I duped a bunch of RX50s, I used Verbatim
"DSDD" media.  Forget about searching for "96 tpi" or "100 tpi" branded
floppies--all that indicates is that verification was performed as part
of manufacturing QA at the indicated track density--it doesn't really
have a bearing on the results.  If a DSDD floppy is good at 360KB, the
chances are overwhelming that it'll be fine in DSQD mode.

As far as ring-less hub floppies go, those are difficult to find and
probably quite old, unless they're specifically labeled (complete with
little arrows) for RX50 use.  Hub rings differ between brands in
thickness; the "clear" type are generally thinner than the opaque (black
or white) ones.

As an aside, the reinforcing ring was originally introduced for early FH
5.25" drives that didn't have circuitry to sense when a disk was being
inserted and activate the spindle motor.  The result that a floppy could
be clamped off-center and mangle the hub area and the data on the floppy
itself.  I remember that Dysan and Verbatim started doing this when the
old un-modified Micropolis drives were in use.  Initially, it started
with a supplied jig and a bunch of self-stick hub rings.  In a short
time, the jig and rings were dropped and floppies simply came with the
rings applied.

As most 8" drives of the time have AC line motors that spin
continuously, this mis-registration was never a problem there.  When
half-height DC-spindle motor 8" drives came out, the problem was already
known in the industry, so 8" floppies don't have the rings.

1.2M (DSHD) floppy drives came much later, after the problem had been
diagnosed and remedied, so those don't *unually* have hub rings.

FWIW,
Chuck

RE: VR241 Stray Wire

[tony duell]

> Yes I have your schematic and I had looked to see if I could see the wire
> but I had failed to spot it. Thanks for pointing it out. My worry was simply
> that I had not noted where it connected, but it seems it wasn't connected in
> the first place.

To prevent it shorting, stick it onto the pin labelled 'S'. If the pins
aren't labelled, do a contiuity test between the socket end of the wire
and each of the pins, it should be a dead short to one of them and an
open circuit to the other. Stick it on the one it seems to be shorted to.

-tony

RE: VR241 Stray Wire

[Rob Jarratt]

> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of tony
duell
> Sent: 25 June 2016 16:49
> To: r...@jarratt.me.uk; General Discussion: On-Topic and Off-Topic Posts
> 
> Subject: RE: VR241 Stray Wire
> 
> > You can see the wire in question at the bottom of the picture below,
> > it is the green wire with a single-pin connector on it, and the size
> > link connector is the two-pronged connector just below it in the photo:
> >
> > https://1drv.ms/i/s!AlQc3lJwQx7bgbAJQx-HsvGY8Gcqsg
> >
> > Anyone know where this wire should go?
> 
> I believe you have 'my' schematic of the VR241. I think this wire is shown
on
> sheet 2 of the scan board diagram, (page
> 7 of the .pdf file) just above C718. It's on the daughterboard that
carries the
> horizontal output transistor, and is fitted onto one of 2 pins on that
board
> labelled 'S' and 'L'. In one position it does nothing (so leaving it free
would do
> no harm provided it doesn't short to anything), in the other is
short-circuits
> C718.
> 


Yes I have your schematic and I had looked to see if I could see the wire
but I had failed to spot it. Thanks for pointing it out. My worry was simply
that I had not noted where it connected, but it seems it wasn't connected in
the first place.

Regards

Rob

Re: Current source for RX50 media?

[Fred Cisin]

On Sat, 25 Jun 2016, Warner Losh wrote:

I was looking at the wrong row in my tables. The RX-50 uses the
300K transfer rate, while the 1.2MB IBM-AT floppy uses 500k. The
rotation rate is different, but I'm having trouble locating that. Sorry
for the possibly bad info. I added support for RX-50 to the FreeBSD
driver (preliminary, mostly works for reading, writing has issues and
formatting doesn't work) several years ago, so I needed to know...


Your info is good.

The RX-50 and the IBM "360K" when in their correct drives, spin at 300 
RPM, with a data transfer rate of 250K bits per second.   The "360K" is 
40track/48tpi; RX-50 is 80track/96tpi


The IBM "1.2M" diskettes (and 8"DD) spin at 360 RPM, with a data transfer 
rate of 500K bits per second.   80track/96tpi


It gets more squirrelly when you want to use a "360K" disk (or RX-50) in a 
"1.2M" drive!
You can either change the drive speed to 300RPM (on drives that support 
both speeds) and use a 250K data transfer rate, OR (on drives that don't 
change speed) leave the speed at 360 RPM, and change the data transfer 
rate to 300K bits per second to compensate for the different rotational 
speed.  (It can get confusing because "300" is both the rotational speed 
of the "360K" and RX-50, AND is the data transfer rate when compensating 
for 360RPM, AND is the Oersted (coercivity) of the disks for "360K" and 
RX-50.  "360" is both the rotational speed of "1.2M" and 8", AND is the 
polpular nake for IBM's DSDD 5150/5160 disks)



Since the RX-50 is DD with 80 track/96tpi  (what the marketing people 
called "QUAD density"), a "360K" drive won't work.
A "1.2M" drive is 80 track/96tpi, but is more commonly used at 360 RPM and 
density that the marketing people called "high" (which is what the 
marketing people were; you won't believe what the Superbrain/Intertec 
people called DSDD80track!)


The RIGHT drive for RX-50 would be a 5.25" "720K" drive, which weren't 
commonly used on PC.  Such as Tandon TM100-4, Shugart/Matsushita 465, or 
Teac 55F.
("1.2M drives are #475 or 55G.  55FG is a "1.2M" drive that is explicitly 
intended to also be able to do "720K".  Some "1.2M" drives can switch 
between 300RPM and 360RPM, some are stuck at 360RPM and need a data 
transfer rate change to compensate)



Because the "1.2M" drive needed to also be able to read "360K" diskettes, 
provision was made.   40 track V 80 track can be read just fine by using 
every other track, BUT because the track width is different a "1.2M" drive 
does not adequately cover/erase a wide ("360K" track that it tries to 
write over.

(1/3mm track width at 1/2mm spacing V 1/6mm track width at 1/4mm spacing)
Need an analogy?  Two bicyles can ride on the tracks made by a car, but 
the bicycle tire-prints won't obliterate the car tire-prints.


In addition, for "360K" in a "1.2M" drive, either the rotational speed or 
the data transfer rate needs to change.


SO, . . .
to to do RX-50 in a "1.2M" drive, we need the 80track/96tpi track spacing, 
but the "360K" RPM/data transfer rate.



Proper:  300RPM  with   250K data transfer rate,  96tpi.
"1.2M" kludge:   360RPM  with   300K data transfer rate,  96tpi


(Note: the Tandon TM100-4 is an excellent drive for this, but the TM100-4M 
is 100tpi instead of 96!)



RX-50 and "360K" diskettes both have a coercivity of 300 Oersted.  BUT, 
"360K" is tested at 48tpi.  If there are flaws between the tracks, they 
won't be spotted in testing, but will show up for RX-50!  So, ideally, 
you want disks tested for 96tpi (marketing "quad density"), or GOOD disks 
without flaws, even between the tracks.  In theory, any good "360K" 
diskette should do, but some folk have encountered errors on disks not 
tested for 96tpi.


"1.2M" diskettes have a coercivity of 600 Oersted.  When written by a 
drive expecting 300 Oersted, data longevity may be shortened.  (Roytype 
"HD" with TRS80 had an average data retention of less than an hour)  Do 
NOT use "HD" ("1.2M") diskettes for any RX-50 data that you would like to 
keep.



--
Grumpy Ol' Fred ci...@xenosoft.com

RE: VR241 Stray Wire

[tony duell]

> You can see the wire in question at the bottom of the picture below, it is
> the green wire with a single-pin connector on it, and the size link
> connector is the two-pronged connector just below it in the photo:
> 
> https://1drv.ms/i/s!AlQc3lJwQx7bgbAJQx-HsvGY8Gcqsg
> 
> Anyone know where this wire should go?

I believe you have 'my' schematic of the VR241. I think this
wire is shown on sheet 2 of the scan board diagram, (page
7 of the .pdf file) just above C718. It's on the daughterboard
that carries the horizontal output transistor, and is fitted onto
one of 2 pins on that board labelled 'S' and 'L'. In one position
it does nothing (so leaving it free would do no harm provided it
doesn't short to anything), in the other is short-circuits C718.

-tony

VR241 Stray Wire

[Rob Jarratt]

I took apart my VR241 recently to see if I could find the reason why the
screen doesn't go completely black. I took lots of pictures while doing so,
to make sure I could put it back together again correctly. However, now that
I am putting it back together, there is one wire which looks like it wasn't
connected. It is on the deflection board (on the right when looking from the
back of the CRT).

 

I am not sure now if I missed taking a photo of this when it was connected,
or if it really should be not connected. There is a pin marked Size Link
near to it, which might be where it has to go, and sounds like an optional
thing if that is the case.

 

You can see the wire in question at the bottom of the picture below, it is
the green wire with a single-pin connector on it, and the size link
connector is the two-pronged connector just below it in the photo:

 

https://1drv.ms/i/s!AlQc3lJwQx7bgbAJQx-HsvGY8Gcqsg

 

 

Anyone know where this wire should go?

 

Regards

 

Rob

Re: Wanted: Ann Arbor Ambassador terminal

[Noel Chiappa]

> From: Richard Loken

> I have an Ann Arbor Ambassador here with the original owner's manual.

If anyone else has _another_ AAA, I'd like one too! (I'm assuming Ian's going
to be getting this one! :-)

They were wonderful terminals, in their day - the largest screen of any
terminal easily available at the time. People in Tech Sq preferred them to
VT*, etc for that reason.

Noel

Re: options for replacing failed small ROMs in PDP-11

[Noel Chiappa]

> From: Glen Slick

> the part is listed as DM8598-AD, where a DM8598 is a 256-bit (32x8)
> tri-state bipolar mask ROM.
> Some substitute T.S. PROMs include the Signetics 82S123

On my M8101, it's an 82S123, which is a tri-state programmable PROM (the
82S23 is the open-collector version of that chip). Those should be relatively
easy to obtain.

BTW, quick question: if a fusible link PROM 'fails' because one of the
fusible links regrows, is it possible to 're-program' that particular chip,
back to the 'original contents'? Some programmers might barf (because they
want the chip to be 'empty' to start with'), but maybe one of those home-brew
pgrogrammers could 'refresh' the chip (thereby avoiding using up a new chip,
when it's not really needed)?


  > From: Curtis H. Wilbar Jr.

  > Is there a file containing the image ?

I'd really like to accumulate a database of the contents of all the PROM
components for all the PDP-11 CPU's. I've got a few of them (for the -11/05),
but there are zillions more.

Anytime anyone creates one, can you please send me a copy, and I'll try and
get them organized and uploaded (and if I _really_ get ambitious, I might try
and start filling in the gaps).

Noel

Re: CDC 6600 - Why so awesome?

[Lionel Johnson]

On 23/06/2016 10:54 PM, Toby Thain wrote:

On 2016-06-23 3:20 AM, Lionel Johnson wrote:

...
I joined CDC in Melbourne, Aust in 1972, worked mostly on 3200 machines
- Didn't like the Cybers, but admired the horsepower. I could fix a
3200, every time, that was the best training I ever had, alone with my
machine in Hobart, I loved it. When that ended, got into PDP 3rd party
maint. Thus was a career made.
Lionel.




Hi Lionel

I heard that the Royal Melbourne Institute of Technology had a 6600? 
Presumably you worked on it?


--Toby

No, Toby, I didn't go to RMIT, as I was on the 3200 mntnce team, worked 
out of Head Office, mostly on the road to sites around Melbourne. CSIRO 
( 3 sites ) Monash Uni, and the in-house machine. Lots of 200UT calls - 
usually clean and adjust throat gap on the card reader. It was better 
when I transferred to Hobart,

it was all on-site at the Bureau of Stats. Best job I ever had.

Lionel.

Re: ACARD ARS-2000SUP versus SCSI2SD - round 1

[pete]

On 25/06/2016 12:15, Ben Sinclair wrote:

On Fri, Jun 24, 2016 at 8:52 PM, Swift Griggs  wrote:


Once I'm done I'll hook both of these up to a FreeBSD box, dd off full
backups, then start over again and try with ZFS under FreeBSD via a PCI
SCSI controller. Then again under IRIX if I still have the energy.


I'd love to see results under IRIX, as I was thinking of trying one or both
of those myself!


Seconded, though it looks like it'll be considerably slower than a real 
SCSI2 hard drive.


--
Pete
Pete Turnbull

Re: ACARD ARS-2000SUP versus SCSI2SD - round 1

[Ben Sinclair]

On Fri, Jun 24, 2016 at 8:52 PM, Swift Griggs  wrote:

>
> Once I'm done I'll hook both of these up to a FreeBSD box, dd off full
> backups, then start over again and try with ZFS under FreeBSD via a PCI
> SCSI controller. Then again under IRIX if I still have the energy.
>

I'd love to see results under IRIX, as I was thinking of trying one or both
of those myself!

Ben Sinclair
b...@bensinclair.com

Re: Current source for RX50 media?

[Warner Losh]

On Fri, Jun 24, 2016 at 11:54 PM, Warner Losh  wrote:
> On Fri, Jun 24, 2016 at 10:20 PM, Ethan Dicks  wrote:
>> My usual 5.25" drive (I have several) is the Teac FD55GFR - strapped
>> for RX33 use with DEC controllers or strapped slightly differently for
>> PC use (I know the directions are floating around)
>
> The RX-50 is a 80-track version of the 360k IBM-PC 40 track floppies.
> It was formatted at 10 sectors per track with smaller inter-sector padding
> bytes than normal. It uses the same rotation rate and data transfer rate
> as the older drive, which is different than the AT formatted floppies
> use.
>
> So RX-50's use 250k transfer rate, 80 tracks, usually 1 side (though
> the controller supports 2 sides, the physical RX-50's don't). 512 byte
> sectors. 16 bytes between sectors (as opposed to either 35 or 42
> for IBM-PC floppies) with 46 bytes format gap (as opposed to 80
> for IBM-PC floppies). This is how you got 400k out of a single sided
> 80 tracked disk. IIRC, the rotation rate is 300 for RX-50 and old
> IBM-PC vs 350 for the IBM-AT drive. All these niggling differences
> cause problems...

I was looking at the wrong row in my tables. The RX-50 uses the
300K transfer rate, while the 1.2MB IBM-AT floppy uses 500k. The
rotation rate is different, but I'm having trouble locating that. Sorry
for the possibly bad info. I added support for RX-50 to the FreeBSD
driver (preliminary, mostly works for reading, writing has issues and
formatting doesn't work) several years ago, so I needed to know...

Warner

Re: Grey Wall (VMS) available

[Warner Losh]

On Fri, Jun 24, 2016 at 1:24 PM, Jay West  wrote:
>
> Mark wrote...
> -
> Please say southern California... ;)
> -
> No, but at least the general region
>
> The lady got back with me just now and provided the following additional
> info (including location). Please contact me off-list if interested/willing
> to get 'em!
>
> ===
> VMS Programming Vols 1-9
> VMS General User 1-6b
> Systems Management Vols 1-5b (8 total)
>
> Denver, CO

I live in Denver and will go fetch these if someone wants to pay for shipping.
These will qualify for book rate if you don't need them ASAP.

Warner