[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[Bill Gunshannon via cctalk]

On 9/8/2023 5:07 PM, Zane Healy wrote:



On Sep 8, 2023, at 6:20 AM, Bill Gunshannon via cctalk  
wrote:


On 9/7/2023 9:20 PM, Gavin Scott via cctalk wrote:

On Thu, Sep 7, 2023 at 4:49 PM ste...@malikoff.com steven--- via
cctalk  wrote:

Here in Oz, VAX has been a popular brand of vacuum cleaner for many decades. We 
had one until recently.
https://www.vax.com.au/

http://catb.org/jargon/html/V/VAX.html


"Nothing sucks like a VAX!!"   :-)


bill



I rather like the old Trade Show button from WordPerfect that is sitting on top 
of the Keyboard I’m using to type this (an old Apple ADB Extended II Keyboard 
via USB converter), it says “Loyal to VAX”.

I normally have a physical VAX running 24x7.  It was shutdown recently, but 
only due to high temps, and it’s back online now.



I've been thinking of bringing up a VAX again.  I think I can fix my VXT 
and I think


I now have some hardware that will let me put a PC class LCD monitor on it.

VAXStations just aren't much fun without the graphics.


bill

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[KenUnix via cctalk]

Zane is it accessible remotely? Just curious..

-Ken

On Fri, Sep 8, 2023 at 5:17 PM Zane Healy via cctalk 
wrote:

>
>
> > On Sep 8, 2023, at 6:20 AM, Bill Gunshannon via cctalk <
> cctalk@classiccmp.org> wrote:
> >
> >
> > On 9/7/2023 9:20 PM, Gavin Scott via cctalk wrote:
> >> On Thu, Sep 7, 2023 at 4:49 PM ste...@malikoff.com steven--- via
> >> cctalk  wrote:
> >>> Here in Oz, VAX has been a popular brand of vacuum cleaner for many
> decades. We had one until recently.
> >>> https://www.vax.com.au/
> >> http://catb.org/jargon/html/V/VAX.html
> >
> >
> > "Nothing sucks like a VAX!!"   :-)
> >
> >
> > bill
> >
> >
>
> I rather like the old Trade Show button from WordPerfect that is sitting
> on top of the Keyboard I’m using to type this (an old Apple ADB Extended II
> Keyboard via USB converter), it says “Loyal to VAX”.
>
> I normally have a physical VAX running 24x7.  It was shutdown recently,
> but only due to high temps, and it’s back online now.
>
> Zane
>
>
>

-- 
End of line
JOB TERMINATED

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[Zane Healy via cctalk]

> On Sep 8, 2023, at 6:20 AM, Bill Gunshannon via cctalk 
>  wrote:
> 
> 
> On 9/7/2023 9:20 PM, Gavin Scott via cctalk wrote:
>> On Thu, Sep 7, 2023 at 4:49 PM ste...@malikoff.com steven--- via
>> cctalk  wrote:
>>> Here in Oz, VAX has been a popular brand of vacuum cleaner for many 
>>> decades. We had one until recently.
>>> https://www.vax.com.au/
>> http://catb.org/jargon/html/V/VAX.html
> 
> 
> "Nothing sucks like a VAX!!"   :-)
> 
> 
> bill
> 
> 

I rather like the old Trade Show button from WordPerfect that is sitting on top 
of the Keyboard I’m using to type this (an old Apple ADB Extended II Keyboard 
via USB converter), it says “Loyal to VAX”.

I normally have a physical VAX running 24x7.  It was shutdown recently, but 
only due to high temps, and it’s back online now.

Zane

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[Bill Gunshannon via cctalk]

On 9/8/2023 9:29 AM, Raymond Wiker via cctalk wrote:



On 8 Sep 2023, at 15:20, Bill Gunshannon via cctalk  
wrote:


On 9/7/2023 9:20 PM, Gavin Scott via cctalk wrote:

On Thu, Sep 7, 2023 at 4:49 PM ste...@malikoff.com steven--- via
cctalk  wrote:

Here in Oz, VAX has been a popular brand of vacuum cleaner for many decades. We 
had one until recently.
https://www.vax.com.au/

http://catb.org/jargon/html/V/VAX.html


"Nothing sucks like a VAX!!"   :-)

I remember seeing that slogan in the 80s, when I was a student in Glasgow.



When it first showed up it was all the rage on comp.os.vms.

And then I got the announcement signs on the side of the Central 
Scranton Expressway


here in PA announcing "Coming soon - VMS".

Of course, that turned out to be The "Virtual Messaging System" which I 
am sure


people see on their highways every day any more.


bill

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[Raymond Wiker via cctalk]

> On 8 Sep 2023, at 15:20, Bill Gunshannon via cctalk  
> wrote:
> 
> 
> On 9/7/2023 9:20 PM, Gavin Scott via cctalk wrote:
>> On Thu, Sep 7, 2023 at 4:49 PM ste...@malikoff.com steven--- via
>> cctalk  wrote:
>>> Here in Oz, VAX has been a popular brand of vacuum cleaner for many 
>>> decades. We had one until recently.
>>> https://www.vax.com.au/
>> http://catb.org/jargon/html/V/VAX.html
> 
> 
> "Nothing sucks like a VAX!!"   :-)

I remember seeing that slogan in the 80s, when I was a student in Glasgow.

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[Bill Gunshannon via cctalk]

On 9/7/2023 9:20 PM, Gavin Scott via cctalk wrote:

On Thu, Sep 7, 2023 at 4:49 PM ste...@malikoff.com steven--- via
cctalk  wrote:

Here in Oz, VAX has been a popular brand of vacuum cleaner for many decades. We 
had one until recently.
https://www.vax.com.au/

http://catb.org/jargon/html/V/VAX.html



"Nothing sucks like a VAX!!"   :-)


bill

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[ben via cctalk]

On 2023-09-07 3:44 p.m., ste...@malikoff.com steven--- via cctalk wrote:



On 09/07/2023 2:36 AM AEST Mike Katz via cctalk  wrote:
Does VAX have nothing to do with vacuum cleaners?


Here in Oz, VAX has been a popular brand of vacuum cleaner for many decades. We 
had one until recently.
https://www.vax.com.au/

Steve


I say a good item to have, when the bit bucket overflows.
Ben.

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[Gavin Scott via cctalk]

On Thu, Sep 7, 2023 at 4:49 PM ste...@malikoff.com steven--- via
cctalk  wrote:
> Here in Oz, VAX has been a popular brand of vacuum cleaner for many decades. 
> We had one until recently.
> https://www.vax.com.au/

http://catb.org/jargon/html/V/VAX.html

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[Tarek Hoteit via cctalk]

TRUE! Only the vintage folks (us) would appreciate what or how we think

Earlier today Paul Koning sent a post under a seperate thread  “….,  (movb 
#1,r0) fetches the instruction and increments PC by 2, thfetches the word where 
the PC points and increments by 2, not 1 again.” And then sent a correction 
"R7)+, actually; @(R7)+ is absolute.  …”. I swear when I read it, I thought how 
my  20yr old  kids or even my lifelong wife would react if  I echoed back the 
same words to them……… 


- - - - - - - - - - - - -
Tarek Hoteit
ta...@infocom.ai
+1 360-838-3675

https://infocom.ai



> On Sep 7, 2023, at 5:25 PM, Mike Katz  wrote:
> 
> Whom ever said youth is wasted on the young was telling a very serious truth.
> 
> On 9/7/2023 7:12 PM, Tarek Hoteit wrote:
>> Safe recovery! Yes, the physical human OLD sucks (not the geeky-part <- 
>> guess that keeps us more functioning)  
>> 
>> - - - - - - - - - - - - -
>> Tarek Hoteit
>> ta...@infocom.ai 
>> +1 360-838-3675
>> 
>> https://infocom.ai 
>> 
>> 
>>> On Sep 7, 2023, at 5:07 PM, Mike Katz via cctalk  
>>>  wrote:
>>> 
>>> My sympathies to both of you and wishes for a good and complete recovery.
>>> 
>>> 2 years ago I had a heart attack in my dojo.   8 stents and a pacemaker 
>>> later I was back on the mat in 3 weeks.  It was 6 months before I was able 
>>> to go full speed.
>>> 
>>> Getting old sucks!!!
>>> 
>>> 
>>> 
>>> On 9/7/2023 6:58 PM, KenUnix via cctalk wrote:
 Jon,
 
 Yea. It affected my left side. Loss of muscle strength. I am left handed
 and lost my strength but luckily can still type albeit slower.
 
 Good thing the keyboard has a backspace key.
 
 Fortunately I still get ideas but it sometimes takes awhile to write them
 down.
 
 -Ken
 
 On Thu, Sep 7, 2023 at 7:32 PM Jon Elson via cctalk 
  
 wrote:
 
> On 9/7/23 17:18, KenUnix via cctalk wrote:
>> Hi guys.
>> 
>> Since I can't get out due to my stroke, be sure to post plenty of snaps
> of
>> the event...
>> 
> Sorry to hear about that.  I had a very mild stroke 2 years
> ago, but it has affected dexterity in my right hand.  My
> writing is now horrible (my penmanship was never really
> great) and typing is more error prone than before.
> 
> Jon
> 
> 
>>> 
>> 
> 

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[Mike Katz via cctalk]

Whom ever said youth is wasted on the young was telling a very serious 
truth.


On 9/7/2023 7:12 PM, Tarek Hoteit wrote:
Safe recovery! Yes, the physical human OLD sucks (not the geeky-part 
<- guess that keeps us more functioning)


- - - - - - - - - - - - -
Tarek Hoteit
ta...@infocom.ai
+1 360-838-3675

https://infocom.ai



On Sep 7, 2023, at 5:07 PM, Mike Katz via cctalk 
 wrote:


My sympathies to both of you and wishes for a good and complete recovery.

2 years ago I had a heart attack in my dojo.   8 stents and a 
pacemaker later I was back on the mat in 3 weeks. It was 6 months 
before I was able to go full speed.


Getting old sucks!!!



On 9/7/2023 6:58 PM, KenUnix via cctalk wrote:

Jon,

Yea. It affected my left side. Loss of muscle strength. I am left handed
and lost my strength but luckily can still type albeit slower.

Good thing the keyboard has a backspace key.

Fortunately I still get ideas but it sometimes takes awhile to write 
them

down.

-Ken

On Thu, Sep 7, 2023 at 7:32 PM Jon Elson via cctalk 


wrote:


On 9/7/23 17:18, KenUnix via cctalk wrote:

Hi guys.

Since I can't get out due to my stroke, be sure to post plenty of 
snaps

of

the event...


Sorry to hear about that.  I had a very mild stroke 2 years
ago, but it has affected dexterity in my right hand.  My
writing is now horrible (my penmanship was never really
great) and typing is more error prone than before.

Jon

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[Tarek Hoteit via cctalk]

Safe recovery! Yes, the physical human OLD sucks (not the geeky-part <- guess 
that keeps us more functioning)  

- - - - - - - - - - - - -
Tarek Hoteit
ta...@infocom.ai
+1 360-838-3675

https://infocom.ai



> On Sep 7, 2023, at 5:07 PM, Mike Katz via cctalk  
> wrote:
> 
> My sympathies to both of you and wishes for a good and complete recovery.
> 
> 2 years ago I had a heart attack in my dojo.   8 stents and a pacemaker later 
> I was back on the mat in 3 weeks.  It was 6 months before I was able to go 
> full speed.
> 
> Getting old sucks!!!
> 
> 
> 
> On 9/7/2023 6:58 PM, KenUnix via cctalk wrote:
>> Jon,
>> 
>> Yea. It affected my left side. Loss of muscle strength. I am left handed
>> and lost my strength but luckily can still type albeit slower.
>> 
>> Good thing the keyboard has a backspace key.
>> 
>> Fortunately I still get ideas but it sometimes takes awhile to write them
>> down.
>> 
>> -Ken
>> 
>> On Thu, Sep 7, 2023 at 7:32 PM Jon Elson via cctalk 
>> wrote:
>> 
>>> On 9/7/23 17:18, KenUnix via cctalk wrote:
 Hi guys.
 
 Since I can't get out due to my stroke, be sure to post plenty of snaps
>>> of
 the event...
 
>>> Sorry to hear about that.  I had a very mild stroke 2 years
>>> ago, but it has affected dexterity in my right hand.  My
>>> writing is now horrible (my penmanship was never really
>>> great) and typing is more error prone than before.
>>> 
>>> Jon
>>> 
>>> 
> 

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[Mike Katz via cctalk]

My sympathies to both of you and wishes for a good and complete recovery.

2 years ago I had a heart attack in my dojo.   8 stents and a pacemaker 
later I was back on the mat in 3 weeks.  It was 6 months before I was 
able to go full speed.


Getting old sucks!!!



On 9/7/2023 6:58 PM, KenUnix via cctalk wrote:

Jon,

Yea. It affected my left side. Loss of muscle strength. I am left handed
and lost my strength but luckily can still type albeit slower.

Good thing the keyboard has a backspace key.

Fortunately I still get ideas but it sometimes takes awhile to write them
down.

-Ken

On Thu, Sep 7, 2023 at 7:32 PM Jon Elson via cctalk 
wrote:


On 9/7/23 17:18, KenUnix via cctalk wrote:

Hi guys.

Since I can't get out due to my stroke, be sure to post plenty of snaps

of

the event...


Sorry to hear about that.  I had a very mild stroke 2 years
ago, but it has affected dexterity in my right hand.  My
writing is now horrible (my penmanship was never really
great) and typing is more error prone than before.

Jon

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[KenUnix via cctalk]

Jon,

Yea. It affected my left side. Loss of muscle strength. I am left handed
and lost my strength but luckily can still type albeit slower.

Good thing the keyboard has a backspace key.

Fortunately I still get ideas but it sometimes takes awhile to write them
down.

-Ken

On Thu, Sep 7, 2023 at 7:32 PM Jon Elson via cctalk 
wrote:

> On 9/7/23 17:18, KenUnix via cctalk wrote:
> > Hi guys.
> >
> > Since I can't get out due to my stroke, be sure to post plenty of snaps
> of
> > the event...
> >
> Sorry to hear about that.  I had a very mild stroke 2 years
> ago, but it has affected dexterity in my right hand.  My
> writing is now horrible (my penmanship was never really
> great) and typing is more error prone than before.
>
> Jon
>
>

-- 
End of line
JOB TERMINATED

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[Jon Elson via cctalk]

On 9/7/23 17:18, KenUnix via cctalk wrote:

Hi guys.

Since I can't get out due to my stroke, be sure to post plenty of snaps of
the event...

Sorry to hear about that.  I had a very mild stroke 2 years 
ago, but it has affected dexterity in my right hand.  My 
writing is now horrible (my penmanship was never really 
great) and typing is more error prone than before.


Jon

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[KenUnix via cctalk]

Hi guys.

Since I can't get out due to my stroke, be sure to post plenty of snaps of
the event...

Pizza hold the pepperoni.

-Ken


On Thu, Sep 7, 2023 at 6:06 PM Mike Katz via cctalk 
wrote:

> With Dorothy and the Tin Woodsman as their salespeople 🤣
>
> I think those would be micro-vaxen because they are only single user.
>
> On 9/7/2023 4:44 PM, ste...@malikoff.com steven--- via cctalk wrote:
> >> On 09/07/2023 2:36 AM AEST Mike Katz via cctalk 
> wrote:
> >> Does VAX have nothing to do with vacuum cleaners?
> > Here in Oz, VAX has been a popular brand of vacuum cleaner for many
> decades. We had one until recently.
> > https://www.vax.com.au/
> >
> > Steve
>
>

-- 
End of line
JOB TERMINATED

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[Mike Katz via cctalk]

With Dorothy and the Tin Woodsman as their salespeople 🤣

I think those would be micro-vaxen because they are only single user.

On 9/7/2023 4:44 PM, ste...@malikoff.com steven--- via cctalk wrote:

On 09/07/2023 2:36 AM AEST Mike Katz via cctalk  wrote:
Does VAX have nothing to do with vacuum cleaners?

Here in Oz, VAX has been a popular brand of vacuum cleaner for many decades. We 
had one until recently.
https://www.vax.com.au/

Steve

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[ste...@malikoff.com steven--- via cctalk]

> On 09/07/2023 2:36 AM AEST Mike Katz via cctalk  wrote:
> Does VAX have nothing to do with vacuum cleaners?

Here in Oz, VAX has been a popular brand of vacuum cleaner for many decades. We 
had one until recently.
https://www.vax.com.au/

Steve

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[Paul Koning via cctalk]

> On Sep 7, 2023, at 9:12 AM, Paul Koning via cctalk  
> wrote:
> 
> 
> 
>> On Sep 7, 2023, at 3:17 AM, Lars Brinkhoff  wrote:
>> 
>> Paul Koning wrote:
>>> Even then it increments by 2, by special exception.  So 112700, 1
>>> (movb #1,r0) fetches the instruction and increments PC by 2, then
>>> fetches the word where the PC points and increments by 2, not 1,
>>> again.
>> 
>> It's not really a special exception because immediate mode is @(R7)+.
> 
> (R7)+, actually; @(R7)+ is absolute.  I meant "special exception" because 
> auto inc/dec of R6 and R7 always increments by 1, while for R0-R5 it 
> increments by the datum size.

Oops, typo.  Of course, auto inc/dec of R6 and R7 (SP and PC) always increment 
by TWO, while auto inc/dec of other registers increments by the size of 
whatever is accessed.

paul

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[Paul Koning via cctalk]

> On Sep 7, 2023, at 3:17 AM, Lars Brinkhoff  wrote:
> 
> Paul Koning wrote:
>> Even then it increments by 2, by special exception.  So 112700, 1
>> (movb #1,r0) fetches the instruction and increments PC by 2, then
>> fetches the word where the PC points and increments by 2, not 1,
>> again.
> 
> It's not really a special exception because immediate mode is @(R7)+.

(R7)+, actually; @(R7)+ is absolute.  I meant "special exception" because auto 
inc/dec of R6 and R7 always increments by 1, while for R0-R5 it increments by 
the datum size.

paul

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[Lars Brinkhoff via cctalk]

Paul Koning wrote:
> Even then it increments by 2, by special exception.  So 112700, 1
> (movb #1,r0) fetches the instruction and increments PC by 2, then
> fetches the word where the PC points and increments by 2, not 1,
> again.

It's not really a special exception because immediate mode is @(R7)+.

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[Fritz Mueller via cctalk]

> On Sep 6, 2023, at 12:48 PM, Paul Koning via cctalk  
> wrote:
> 
> The weird case of the 11/05 is because the general registers are assigned 
> addresses 177700 through 177707 for R0 through PC, so R1 is at 177701 even 
> though it's a word wide.  On most models those addresses only work from the 
> operator console, but on the 11/05 they are also visible from the program.  
> And by special microcode hack ("just because they could", says ABC) if the PC 
> is in that range it increments by 1.


This was on the tip of my tongue because I was actually just debugging these 
very bits of microcode on a GT40 (which Scott Swazey will be demoing at VCFMW 
running “Lunar Lander” if it survives the journey there by car!)

The ALU B-leg input in the data paths on this CPU has a selection to generate 
constant +1.  In the usual cases, where the microcode needs +2 to be added to 
something, the additional +1 comes from a microcode field bit and is added in 
at the ALU least-significant-bit-slice carry input.  There is additional 
circuitry to inhibit this carry input in special cases like internal register 
address decodes, etc.

On our GT40, we had a microcode PROM failure which took out this very carry 
source bit.  Thus our GT40 PC was incrementing by just one _incorrectly_ in 
most cases where it should have been incrementing by two.  Quite a coincidence 
that your question came up soon after dealing with this :-)

—FritzM.

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[Paul Koning via cctalk]

> On Sep 6, 2023, at 3:32 PM, Jon Elson via cctalk  
> wrote:
> 
> On 9/6/23 14:00, Mike Katz via cctalk wrote:
>> Paul,
>> 
>> I'm not an 11 expert but don't most instruction fetches (or the last clock 
>> phase on an instruction) cause the pc to increment by one?
> PDP-11 instructions are 16-bit.  Since memory is byte-addressed, the 
> instruction counter should normally increment by 2, except where immediate  
> operands are used.

Even then it increments by 2, by special exception.  So 112700, 1 (movb #1,r0) 
fetches the instruction and increments PC by 2, then fetches the word where the 
PC points and increments by 2, not 1, again.

The weird case of the 11/05 is because the general registers are assigned 
addresses 177700 through 177707 for R0 through PC, so R1 is at 177701 even 
though it's a word wide.  On most models those addresses only work from the 
operator console, but on the 11/05 they are also visible from the program.  And 
by special microcode hack ("just because they could", says ABC) if the PC is in 
that range it increments by 1.

paul

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[Nigel Johnson Ham via cctalk]

And for a bonus point, which signal description had an asterisk beside 
it with a footnote, "add an extra 20 minutes on Saturday night" before 
marketing found out and scotched it?


cheers,

Nigel



Nigel Johnson, MSc., MIEEE, MCSE VE3ID/G4AJQ/VA3MCU
Amateur Radio, the origin of the open-source concept!
Skype: TILBURY2591


On 2023-09-06 15:00, Mike Katz via cctalk wrote:

Paul,

I'm not an 11 expert but don't most instruction fetches (or the last 
clock phase on an instruction) cause the pc to increment by one?


On 9/6/2023 12:08 PM, Paul Koning via cctalk wrote:
Reminds me of the "PDP-11 trivia contest" that was held at DECUS, I 
think on the occasion of the 20th anniversary of the PDP-11.  If so 
that would have been 2000.  I still have the poster that went with it 
somewhere.  And I remember the question I contributed: "On what model 
and under what circumstances will the PC increment by 1?"


paul

On Sep 6, 2023, at 12:36 PM, Mike Katz via cctalk 
 wrote:


Do you understand "Stop this RIM RAM or I will DEC you"?

Do you know what PDP is an acronym for?

Do you think in PDP-11 Assembler.

Do you know the difference between OS/8 and RTS/8.

Is EMACS your friend?

Can you discuss the advantages of Tops 10 over Tops 20.

Have you ever programmed a DEC 18 bit machine?

Does VAX have nothing to do with vacuum cleaners?

If you can answer yes to any of these I am hosting a "DECnut" pizza 
party, at my house, Saturday, September 9th at 7PM with pizza to be 
delivered sometime after that.


If you are interested please stop by my table (first 2 tables to the 
left of the door in the "big iron" room).  Look for the PDP-8/E with 
an RX02 attached.


Please feel free to pass this email on to any DEC fan.

Thanks,

  Mike



--
Nigel Johnson, MSc., MIEEE, MCSE VE3ID/G4AJQ/VA3MCU
Amateur Radio, the origin of the open-source concept!
Skype:  TILBURY2591

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[Paul Koning via cctalk]

> On Sep 6, 2023, at 3:00 PM, Mike Katz via cctalk  
> wrote:
> 
> Paul,
> 
> I'm not an 11 expert but don't most instruction fetches (or the last clock 
> phase on an instruction) cause the pc to increment by one?

No, by 2 because memory addresses are byte addresses but instructions are 
2-byte words and word aligned.

I just remembered two other PDP-11 trivia questions, not model dependent.

1. Describes a one-word program that executes backward in memory.
2. Describe a one-word program that clears the entire 16-bit address space, 
halting on completion.

paul

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[Jon Elson via cctalk]

On 9/6/23 14:00, Mike Katz via cctalk wrote:

Paul,

I'm not an 11 expert but don't most instruction fetches 
(or the last clock phase on an instruction) cause the pc 
to increment by one?
PDP-11 instructions are 16-bit.  Since memory is 
byte-addressed, the instruction counter should normally 
increment by 2, except where immediate  operands are used.


Jon

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[Jon Elson via cctalk]

On 9/6/23 12:08, Paul Koning via cctalk wrote:

Reminds me of the "PDP-11 trivia contest" that was held at DECUS, I think on the occasion 
of the 20th anniversary of the PDP-11.  If so that would have been 2000.  I still have the poster 
that went with it somewhere.  And I remember the question I contributed: "On what model and 
under what circumstances will the PC increment by 1?"

The PDP-11 was introduced in 1970, so the 20th anniversary 
would have been 1990, or 2000 would have been the 30th.


Jon

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[Mike Katz via cctalk]

Paul,

I'm not an 11 expert but don't most instruction fetches (or the last 
clock phase on an instruction) cause the pc to increment by one?


On 9/6/2023 12:08 PM, Paul Koning via cctalk wrote:

Reminds me of the "PDP-11 trivia contest" that was held at DECUS, I think on the occasion 
of the 20th anniversary of the PDP-11.  If so that would have been 2000.  I still have the poster 
that went with it somewhere.  And I remember the question I contributed: "On what model and 
under what circumstances will the PC increment by 1?"

paul


On Sep 6, 2023, at 12:36 PM, Mike Katz via cctalk  wrote:

Do you understand "Stop this RIM RAM or I will DEC you"?

Do you know what PDP is an acronym for?

Do you think in PDP-11 Assembler.

Do you know the difference between OS/8 and RTS/8.

Is EMACS your friend?

Can you discuss the advantages of Tops 10 over Tops 20.

Have you ever programmed a DEC 18 bit machine?

Does VAX have nothing to do with vacuum cleaners?

If you can answer yes to any of these I am hosting a "DECnut" pizza party, at 
my house, Saturday, September 9th at 7PM with pizza to be delivered sometime after that.

If you are interested please stop by my table (first 2 tables to the left of the door in 
the "big iron" room).  Look for the PDP-8/E with an RX02 attached.

Please feel free to pass this email on to any DEC fan.

Thanks,

  Mike

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[Paul Koning via cctalk]

> On Sep 6, 2023, at 1:14 PM, Fritz Mueller  wrote:
> 
> 
>> On Sep 6, 2023, at 10:08 AM, Paul Koning via cctalk  
>> wrote:
>> "On what model and under what circumstances will the PC increment by 1?"
> 
> At least true on a KD11-B when executing code out of the memory-mapped 
> register file :-)

Correct... PDP11/05 and /10.

paul

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[Fritz Mueller via cctalk]

> On Sep 6, 2023, at 10:08 AM, Paul Koning via cctalk  
> wrote:
> "On what model and under what circumstances will the PC increment by 1?"

At least true on a KD11-B when executing code out of the memory-mapped register 
file :-)

(I just happen to have been wading through one of these a couple weeks back…)

—FritzM.

[cctalk] Re: Vintage Computer Fest Midwest "DECnut" pizza party

[Paul Koning via cctalk]

Reminds me of the "PDP-11 trivia contest" that was held at DECUS, I think on 
the occasion of the 20th anniversary of the PDP-11.  If so that would have been 
2000.  I still have the poster that went with it somewhere.  And I remember the 
question I contributed: "On what model and under what circumstances will the PC 
increment by 1?"

paul

> On Sep 6, 2023, at 12:36 PM, Mike Katz via cctalk  
> wrote:
> 
> Do you understand "Stop this RIM RAM or I will DEC you"?
> 
> Do you know what PDP is an acronym for?
> 
> Do you think in PDP-11 Assembler.
> 
> Do you know the difference between OS/8 and RTS/8.
> 
> Is EMACS your friend?
> 
> Can you discuss the advantages of Tops 10 over Tops 20.
> 
> Have you ever programmed a DEC 18 bit machine?
> 
> Does VAX have nothing to do with vacuum cleaners?
> 
> If you can answer yes to any of these I am hosting a "DECnut" pizza party, at 
> my house, Saturday, September 9th at 7PM with pizza to be delivered sometime 
> after that.
> 
> If you are interested please stop by my table (first 2 tables to the left of 
> the door in the "big iron" room).  Look for the PDP-8/E with an RX02 attached.
> 
> Please feel free to pass this email on to any DEC fan.
> 
> Thanks,
> 
>  Mike