Re: Is it really that quiet out there?

[Sam O'nella via cctalk]

Yes, but the irony if us replying on-list isn't lost.
 Original message From: Robert via cctalk 
 Date: 10/24/17  11:40 AM  (GMT-06:00) To: "General 
Discussion: On-Topic and Off-Topic Posts"  Subject: Re: 
Is it really that quiet out there? 
 The last one that I received was October 20th.

Robert

RE: Cleaning and Restoring a Badly Corroded PSU

[Maciej W. Rozycki via cctalk]

On Tue, 24 Oct 2017, Rob Jarratt via cctalk wrote:

> Actually I didn't say they have leaked, but I do say that they could only
> have leaked from the bottom, but you can't tell. This does appear to be what
> happened to some of the capacitors I had on the other PSU I repaired
> recently, although again I can't be sure. However there *is* something on
> the board to which dirt and little shards from the heat sinks appears to be
> sticking at least a bit, but perhaps it is just dirt that has absorbed
> humidity. Certainly the board has been in some kind of humid environment,
> the case itself is quite rusty in places. So it is probably more like
> someone else suggested, and not capacitor leakage but a humid/damp storage
> environment.

 This Nichicon PL 4700µF/10V part as well as all the Chemi-Con SXF parts 
have certainly leaked in almost all the H7826 PSUs I have (which have been 
the worst in this respect), and consequently the PCB has become sticky in 
the output filter area.  Beware that in addition to the output filters 
there's another SXF part just next to the input filter capacitor; it's 
visible on one of your photos, next to the lightning bolt sticker.

 FWIW,

  Maciej

Re: Digression - Ah Yes!! The PDP-10

[Ed via cctalk]

oddly there  were times  you  could   dial into a  broken dec 10 connect 
and end up  connected to someone elses  session Ed#
 
 
 
In a message dated 10/25/2017 2:18:30 P.M. US Mountain Standard Time,  
cctalk@classiccmp.org writes:



> -Original Message-
> From: cctalk  [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Robert
> Adamson via  cctalk
> Sent: 25 October 2017 20:56
> To:  cct...@classiccmp.org
> Subject: Digression - Ah Yes!! The  PDP-10
> 
> Beginning of the 70's I was using a pdp-10 at TSL  (Time Sharing Limited,
UK)
> over a phone line writing logic  simulation software in Fortran. Remember
it
> fondly, especially the  number of times I needed to redial in and try to
> reconnect to my  session. Still smell the teletype. Cost about £10 for the
20
>  seconds cpu-time or so just to compile the program!!!
> 

I used  to use the DECSYSTEM-20 from a Teletype (until they got replaced by
VDUs).  That is why I really wanted a nice Model 33 ASR, which I now have.  
I
sometimes connect it up to SIMH running TOPS-20 to relive the happiest  part
of my school days.


> Roll on a few years and I was  actually at the console of a 10 at Smiths
doing IC
> layout graphics  interactively on their Lady Jane suite. What a great
single-user
>  machine!
> 
> (and I still remember my username and password from  TSL, typed it so 
often
it
> burned in).
>  

Cyclops page (Popular Electronics and Cromemco)

[William Sudbrink via cctalk]

Hi,

 

In case anyone is interested, I have finally cobbled together a web page
that documents the construction of the Popular Electronics Cyclops camera
that I exhibited at the 2016 VCF East.  It also documents my work to produce
a Cromemco S-100 Cyclops that I hope to exhibit at the 2018 VCF East. The
page is here:

 

http://wsudbrink.dyndns.org:8080/cyclops/index.html

 

The Cromemco S-100 Cyclops starts down the page a bit.

 

Bill S.

 



---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

RE: Digression - Ah Yes!! The PDP-10

[Rob Jarratt via cctalk]

> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of Robert
> Adamson via cctalk
> Sent: 25 October 2017 20:56
> To: cct...@classiccmp.org
> Subject: Digression - Ah Yes!! The PDP-10
> 
> Beginning of the 70's I was using a pdp-10 at TSL (Time Sharing Limited,
UK)
> over a phone line writing logic simulation software in Fortran. Remember
it
> fondly, especially the number of times I needed to redial in and try to
> reconnect to my session. Still smell the teletype. Cost about £10 for the
20
> seconds cpu-time or so just to compile the program!!!
> 

I used to use the DECSYSTEM-20 from a Teletype (until they got replaced by
VDUs). That is why I really wanted a nice Model 33 ASR, which I now have. I
sometimes connect it up to SIMH running TOPS-20 to relive the happiest part
of my school days.


> Roll on a few years and I was actually at the console of a 10 at Smiths
doing IC
> layout graphics interactively on their Lady Jane suite. What a great
single-user
> machine!
> 
> (and I still remember my username and password from TSL, typed it so often
it
> burned in).
> 

RE: Cleaning and Restoring a Badly Corroded PSU

[Rob Jarratt via cctalk]

Thanks for the suggestions. I will have to desolder the heatsinks from the 
board though, and then I can try a good clean up as suggested. I know about 
those RIFAs, the H7878 had one but it seemed still OK and this one looks to be 
in good condition, do they show signs of cracking before they go?

Regards

Rob

> -Original Message-
> From: cctalk [mailto:cctalk-boun...@classiccmp.org] On Behalf Of shad
> via cctalk
> Sent: 25 October 2017 21:06
> To: cctalk 
> Subject: RE: Cleaning and Restoring a Badly Corroded PSU
> 
> Hello,
> the vertical heat sinks for the TO220 with this design are fairly common, I 
> saw
> them many times on various boards.
> However, as they are simply aluminum parts, you can clean them for sure.
> After removing the screw, you could try simply with an hard brush.
> If badly corroded, remove the bubbles of oxide with a thin sanding paper, then
> you could restore the opaque aspect submerging for few seconds in caustic
> sodium solution. Be aware to protect eyes and skin!
> 
> Replace the RIFA X2 capacitor
> 
> Andrea

Re: Fujitsu M2235S

[Phil Blundell via cctalk]

On Mon, 2017-10-23 at 20:14 -0500, Jules Richardson via cctalk wrote:
> There appears to be a photo of the internals here, if that helps at
> all:
> 
> http://museum.ipsj.or.jp/computer/device/magnetic_disk/images/0011_03
> _l.jpg
> 
> ... it's a little small, so hard to tell what's going on for sure! I
> don't 
> see any obvious locking mechanism, though.
> 
> There's a Fujitsu M2333KS on ebay - item # 182218376023 - which
> appears to 
> be quite similar in layout. That one appears to have some form of 
> positioner / track 0 sensor accessible from outside the HDA if the
> logic 
> board is removed - is that true of the 2235 too?

Yes, the stepper motor and track 0 sensor is external and, as you say,
you can get at it with the logic board removed (or, to a lesser extent,
though the side of the chassis with the logic board still in situ).

I took the lid off the chamber in the end and confirmed that there was
no latch and the head assembly itself was free to move.  It seemed that
the stepper motor itself was the bit that was stuck.  So, emboldened
with the knowledge that I probably wasn't about to snap the positioner
arm off, I gave it a rather more enthusiastic shove from outside and it
now does move a bit.  I was able to recover the data from the first 26
cylinders but it won't seek beyond track 25 for some reason, possibly
just more mechanical resistance inside the stepper.  There doesn't seem
to be anywhere obvious to add lubrication so I suppose I will just have
to try a bit more force and hope that this frees it up!

Phil

Re: Which Dec Emulation is the MOST useful and Versatile?

[Josh Dersch via cctalk]

On Wed, Oct 25, 2017 at 5:20 AM, william degnan via cctalk <
cctalk@classiccmp.org> wrote:

> On Tue, Oct 24, 2017 at 11:26 PM, Evan Koblentz via cctalk <
> cctalk@classiccmp.org> wrote:
>
> > Related to DEC emulation: is there a visual Straight-8 simulator? I'd
> like
> > to practice working the front panel and such.
> >
>
> I don't think there is one.  The PDP 8i is the closest thing but there are
> I think 26 switches at the bottom the 8i, I think only 18 at the bottom of
> the straight 8.


Both the 8/i and the Straight-8 have the same number of switches (26).
Their function is identical.  The 8/i has a few additional lights, however.

- Josh



> They thus can't be the same exactly but it may be that the
> straight 8 is the same as the 8i, if you use only switches that appear on
> both systems (no step counter on the straight 8).  Dave G will know.
>
> b
>

RE: Cleaning and Restoring a Badly Corroded PSU

[shadoooo via cctalk]

Hello,
the vertical heat sinks for the TO220 with this design are fairly common, I
saw them many times on various boards.
However, as they are simply aluminum parts, you can clean them for sure.
After removing the screw, you could try simply with an hard brush.
If badly corroded, remove the bubbles of oxide with a thin sanding paper,
then you could restore the opaque aspect submerging for few seconds in
caustic sodium solution. Be aware to protect eyes and skin!

Replace the RIFA X2 capacitor

Andrea

Digression - Ah Yes!! The PDP-10

[Robert Adamson via cctalk]

Beginning of the 70's I was using a pdp-10 at TSL (Time Sharing Limited, UK)
over a phone line writing logic simulation software in Fortran. Remember it
fondly, especially the number of times I needed to redial in and try to
reconnect to my session. Still smell the teletype. Cost about £10 for the 20
seconds cpu-time or so just to compile the program!!!

Roll on a few years and I was actually at the console of a 10 at Smiths
doing IC layout graphics interactively on their Lady Jane suite. What a
great single-user machine!

(and I still remember my username and password from TSL, typed it so often
it burned in).

Bob

> -Original Message-
> Date: Tue, 24 Oct 2017 18:42:42 +0100
> From: "Rob Jarratt" 
> To: "'Dave Wade'" , "'General Discussion:
>   On-Topic and Off-Topic Posts'" ,  "'Kip
> Koon'"
>   
> Subject: Re: Which Dec Emulation is the MOST useful and Versatile?.
> Message-ID: <003101d34cef$7eca53c0$7c5efb40$@ntlworld.com>
> Content-Type: text/plain; charset="us-ascii"
> 
> 
> 
> Ah the PDP10! Although the very first computer I used was a PDP11, it
> was so briefly that I really consider the PDP10 (in DECSYSTEM-20 form)
> to be my first computer. It is easy to emulate in SIMH, although the
> SIMH emulation is of a less capable processor (KS10) and I think KLH10
> is the best emulator for that (but I have never used it).
> 
...
> 
> Rob

RE: Which Dec Emulation is the MOST useful and Versatile?

[Rich Alderson via cctalk]

From: Noel Chiappa
Sent: Tuesday, October 24, 2017 11:12 AM

>> From: Kip Koon

>> Back in the day when Bill Gates and company 1st started out ... a B/W photo
>> of a young Bill Gates bending over the operator at what looked like a very
>> small computer. Maybe it was just a terminal. I don't remember. I understand
>> they did software development on a DEC PDP of some sort.

> The very earliest version of their BASIC was done on PDP-10's running TOPS-10
> - first the one at Harvard, and then some commercial time-sharing system in
> the Boston area.

Noel, do have a reference for "some commercial time-sharing system in the
Boston area"?  From Paul Allen's autobiography, the Harvard system was followed
immediately by their move to Albuquerque, where they leased time on the local
school board's PDP-10, and that's what my friends who worked for Micro-soft
back then have told me, as well.

Rich


Rich Alderson
Vintage Computing Sr. Systems Engineer
Living Computers: Museum + Labs
2245 1st Avenue S
Seattle, WA 98134

mailto:ri...@livingcomputers.org

http://www.LivingComputers.org/

HP 2640S terminal for sale in closed Facebook group in Sweden.

[Mattis Lind via cctalk]

https://scontent-arn2-1.xx.fbcdn.net/v/t31.0-8/s720x720/22713265_10156127179398570_2013874287015352972_o.jpg?oh=bcb54c378ce5412749d1ad7ea87afb93=5A777F30

I am not the seller. It looks like it is working. The seller confirms that
there are some screen mold.

If there is anyone that is interested I can get you in contact with the
seller.

/Mattis

Re: Which Dec Emulation is the MOST useful and Versatile?

[william degnan via cctalk]

On Tue, Oct 24, 2017 at 11:26 PM, Evan Koblentz via cctalk <
cctalk@classiccmp.org> wrote:

> Related to DEC emulation: is there a visual Straight-8 simulator? I'd like
> to practice working the front panel and such.
>

I don't think there is one.  The PDP 8i is the closest thing but there are
I think 26 switches at the bottom the 8i, I think only 18 at the bottom of
the straight 8.  They thus can't be the same exactly but it may be that the
straight 8 is the same as the 8i, if you use only switches that appear on
both systems (no step counter on the straight 8).  Dave G will know.

b