As mentioned in other post you need the correct programmer to read the PAL
fuse pattern. You must specify the exact manufacture and part number to
configure the programmer or you can ruin the PAL.
Around 1985 I did an experiment on decoding the logic of PALs with the
security fuse programmed. This used just TTL levels to apply test patterns
to the inputs and read the outputs. For registered devices you would also
apply the clock. You would develop large truth tables that could be
reduced to provide equivalent logic equations. I used the test vector
feature on a Data I/O Logic Pack but you could build a simple test fixture
to apply inputs and read the output levels.
This process should work with simple PALs, 22V10s and 16V8s.Combinatorial
devices like the 16L8 are easy to decode. Apply all possible inputs and read
the outputs. You will need to treat I/O pins as inputs and determine if the
pin is tri-state.
Registered devices such as the 16R8 require a bit of work. Apply an input
and clock it through all possible states, Eight registers would require up
to 256 clocks. Some devices power up in a known or repeatable state, early
devices power up in a random state. Suppose a device powers up to all zeros,
>from that state you need to find all possible next states by applying
various inputs. Reset the part, go to a known state and try input pattern 1
and record the output. Repeat with input pattern 2 and so on. The idea is to
build a state table with all inputs and transitions.
A logic reduction program such as Espresso will simplify these large tables
to minimized equations. I used Data I/O's ABEL program to do this.
This method will only work on devices where the feedback is from the pin so
there are no hidden registers. These PALs have the output enable controlled
by a pin so you can always read the register state. Some devices allowed the
registers to be preloaded to a known state to speed testing. These make it
simple to get to each state to find the transitions to the next state. You
must have the correct programming algorithm to use the feature or you could
ruin the device.
I did this experiment 20 years ago and don't have any more information on
it.
Michael Holley
www.swtpc.com/mholley
>
>Subject: Re: removing parts from PCBs
> From: Paul Koning <pkoning at equallogic.com>
> Date: Wed, 16 Nov 2005 09:24:01 -0500
> To: cctalk at classiccmp.org
>
>>>>>> "woodelf" == woodelf <bfranchuk at jetnet.ab.ca> writes:
>
> >>> Is that the stuff in Cray's? Now we know why they are so much!
> >>>
> >> A relative, but not the same stuff. Cray used Fluorinert F-77,
> >> which boils at about 203F.
>
> woodelf> So what is wrong with cheap water? I guess - inert - says
> woodelf> it all.
>
>Water is not inert, especially not when hot.
>
> paul
The real problem with water is not it's conductivity. High power
tube transmitters have used distilled water in the past as it's a
really poor conductor if kept clean.
DEC experimented with water cooling too. The Aquarius project was
a water cooled VAX. Too many headaches with leakage, heat transfer
to the environment and installation issues. Systems like that use
a chiller and heat exchanger to cool the closed loop water system.
Those are costly and difficult to install. Murder if it should leak
in a computer room. Then there is an efficientcy problem as you end
up using power to move heat which adds heat..
With all that, the circuits they were trying to cool were getting more
power efficient. So by time they worked out wet cooling air cooling
was again attractive or at least far easier.
It's still packaging. ;)
Allison
>
>Subject: Re: Minix
> From: woodelf <bfranchuk at jetnet.ab.ca>
> Date: Thu, 17 Nov 2005 15:19:04 -0700
> To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org>
>
>Allison wrote:
>
>><sarcasm warning>
>>And you want it delivered configured for free.
>>
>>
>>
>yes ! Free is good.
>I even want it shipped.
ah, reading impaired?
>
>But say other than ebay ( something I can't use because stupid scammers
>useing
>my email address ) how much is a PDP - 11 cpu, dual serial card, 64kb
>of memory
>and working mass storage that can be reasionable shipped?
>
>>
>>Allison
>>
>>
>PS and even a power supply and bootstrap rom . Front panel is not needed.
Ok it's very obvious you know nothing of PDP-11s. First, 64kb of memory.
PDP11s have memory mapped IO so the TOP 8kb of memory is IO space. Typically
a loaded PDP11 without MMU is 24-28kW of ram (words as its a 16bitter).
Now with all that been said about models, boards and busses. You expressed
no wish other "I want one.". Well lets all drop a 11/70 mid sized system on
you. Figure about 500 pounds and 3 6ft racks plus a few washing machine
sized disks. Got a spare room with air conditioning. Don't forget you
need a 220V 30A drop for that.
Oh, too big. Ok how about an microPDP11 on about 30" deep, 27" tall and
8" wide. Runs on 120V maybe 4-5a max. Oh weighs in around 60pounds with
a single hard disk of 30mb. Should easily cost more to ship than buy.
Shipping will cost a bomb due to both size and weight. The disk should
be removed and packed seperately. Not a lot of those around but a great find.
Next down is a BA-11VA box about 4x11x13" and only four bual width slots.
Shipable and likely cheap. The trick is using a 11/23 cpu, MXV11 and MRV11
to get over 256k of ram, two serial ports and boot roms in three boards.
Of course theres still no mass storage and RX02 is abou 50 pound rack
mount or at least table top sized. The RQDX3 is an other one board
solution but the BA11VA doesnt support a distribution board or power
for the drives so it's not easily used. RL02 is a quad width, not
usable in that box. Maybe too small a box.
So thats cheap and common usually the BAll-S. Recognizable by the three
toggle switches on the front. had plenty of bus and power for most Qbus
boards. No disk bays and generally meant for rack mounting. So usually
you want one of these in a rack of the 48" or taller. Then disks like
RX02 and RL02 are easily mounted. Not shippable except by freight. The
good news is of all PDP11s they are most common and often free. Try
your local university.
Can't give cost for a reason, soon as you ask the price is what traffic
will support. Suppliers exist for used DEC boards and systems. Prices
are what they are.
Local to me, (less than 10 miles from DEC home central) aka,
The Greater Maynard Area PDP11 systems are common, and usually
free if you haul.
Allison
>>Chris M wrote:
>>
>>
>>
>>>IINM, the first edition was yeller, and had no media.
>>>I don't have it in front of me, but I'm pretty sure it
>>>was numero uno. The source code of course is printed
>>>in the book. And I thought 3 editions were already
>>>released?
>>>
>>>
I have my copy of the book of the first edition in front of me and the
cover is yellow/pale tan. It is copyrighted 1987 and my copy is from
the second printing. It was printed for the US market. It came with no
media; a page inside the book describes the four media distributions
(three different floppy options and a 9-track tape option) with their
ISBN numbers so you could order them from Prentice-Hall.
I remember seeing a red cover version of the book. I think it was when
I was working in Germany in 91-92, but that was too long ago for me to
remember the details.
alan
>
>Subject: Re: Minix
> From: woodelf <bfranchuk at jetnet.ab.ca>
> Date: Thu, 17 Nov 2005 09:08:58 -0700
> To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org>
>
>gordonjcp at gjcp.net wrote:
>
>>I just paid about ?30 for some PDP11/03 boards, CPU, MXV11 and some kind
>>of serial card (can't remember the exact type). I had a BA23 lying around
>>empty, and an RQDX3. Now I need some media...
>>
>>
>>
>Well what about a whole set ? A lot of people like myself can't be
>mix-ing and matching
>part. I just want to pen the box and plug it in if I were to buy one.
Why not? generally building Qbus PDP11s is like the proverbial chinese
menu. One from column A one from B and One from C.
You need a Qbus box there are three common ones.
A cpu there are 4 common cheap ones.
Memory Various and second sources.
Serial IO one will do (or more) gobs of choices.
Common choices are DLV11F (single line) or DLV11J
four line. OR MXV11 (two serial and ram on one card)
The crunch item is storage as it's often big or
if reasonably current like anything SCSI not
common hence expensive.
>PS A small HD would be nice too. I got a terminal already
<sarcasm warning>
And you want it delivered configured for free.
Allison
>
>Subject: Re: Minix
> From: Gordon JC Pearce <gordonjcp at gjcp.net>
> Date: Thu, 17 Nov 2005 20:15:33 +0000
> To: General Discussion: On-Topic and Off-Topic Posts <cctalk at classiccmp.org>
>
>Got an RX50, not got any (known-good) RX50 media. I seem to recall that
>normal 5.25" DD floppies are a no-no, but I can't remember why.
The regular brown media works fine, the problem is 10 512byte sectors per
track and 80 tracks. Not a normal PC format, though it can do it. John Wilsons
putr does it if memory is working today. If you format them on an -11 you
need XXDP as RT-11 doesnt.
If the uVAX2000 has RX50 or RX33 it can format floppies as well as
RQDX3 Compatable hard disks. All from the console test software
So a minimal uVAX2000 (without any OS) can be a useful applience.
I keep one around with longer cables for that reason.
>> The hard disk is st412(10mb), ST225(20mb), st250(40mb), Quantum D540 (30mb).
>> However they must be formatted with either xxdp or deom a system that can
>> such as uVAX2000 (for RQDX3 only).
>
>Yes, I've been reading up on this. Apparently you can modify XXDP to
>handle different formats, too. I *think* I might have an ST225.
St225 is RD31, a standard format.
Allison
