16 Sep
2010
16 Sep
'10
4:52 a.m.
When I was maintaining Alto Is, I put a warning sign on the machines that
stated "Avoid VD --- Venereal Disks! If your disk doesn't load, do NOT try
another machine"...
For the most part the drives were OK, but if they did fail, then the
contagion could be spread. I certainly had my share of disk crashes.
There's a reason the Alto file system had the scavanger and was designed to
be recovered...
16 Sep
16 Sep
12:26 p.m.
There's a reason the Alto file system had the
scavanger and was designed to
be recovered...
I wonder if it's a conincidence that the PERQ POS filesystem recovery
tool is also called 'scavenger' and that the PERQ filesystem also stores
all the pointers at least twice so it's posisble to recover from quite
bad disk corruption. Not that any PERQ had a dmountable hard disk.
-tony
3:24 p.m.
--- On Thu, 9/16/10, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
I wonder if it's a conincidence that the PERQ POS
filesystem recovery
tool is also called 'scavenger' and that the PERQ
filesystem also stores
all the pointers at least twice so it's posisble to recover
from quite
bad disk corruption. Not that any PERQ had a dmountable
hard disk.
The Perq was the result of a visit (sabbatical?) at Xerox PARC
by one of the principals of Three Rivers Computer, much like
the way Lilith originated from Wirth's experiences there.
I believe that the original code name of the Perq was the
"PascAlto", referring to its obvious heritage, but with the
intent to base the software on UCSD Pascal rather than BCPL.
Undoubtedly the Perq owes much to the Alto, as did every other
similar graphical workstation of that era.
--Bill
17 Sep
17 Sep
10:41 a.m.
On 9/16/2010 3:24 PM, William Maddox wrote:
--- On Thu, 9/16/10, Tony Duell<ard at
p850ug1.demon.co.uk> wrote:
My understanding is that Brian Rosen, one of the founders of 3RCC
(creators of the PERQ) worked at Xerox PARC for a time in the mid-late
70's, but he was frustrated with Xerox's inability/unwillingness to
commercialize the Alto in any significant way. The PERQ was the result
of this frustration. So yes, the PERQ was influenced by the Alto in
some rather major ways :).
(There's a nice writeup here:
http://www.chilton-computing.org.uk/acd/sus/perq_history/part_1/c5.htm
-- this is an interesting site to read about ICL/3RCC and the PERQ, just
FYI...)
- Josh
I wonder if it's a conincidence that the PERQ
POS
filesystem recovery
tool is also called 'scavenger' and that the PERQ
filesystem also stores
all the pointers at least twice so it's posisble to recover
from quite
bad disk corruption. Not that any PERQ had a dmountable
hard disk.
The Perq was the result of a visit (sabbatical?) at Xerox PARC
by one of the principals of Three Rivers Computer, much like
the way Lilith originated from Wirth's experiences there.
I believe that the original code name of the Perq was the
"PascAlto", referring to its obvious heritage, but with the
intent to base the software on UCSD Pascal rather than BCPL.
Undoubtedly the Perq owes much to the Alto, as did every other
similar graphical workstation of that era.
--Bill
11 a.m.
--- On Thu, 9/16/10, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
Sure. It was Brian Rosen, I believe.
I wonder if it's a conincidence that the PERQ
POS
filesystem recovery
tool is also called 'scavenger' and that the PERQ
filesystem also stores
all the pointers at least twice so it's posisble to recover
from quite
bad disk corruption. Not that any PERQ had a dmountable
hard disk.
The Perq was the result of a visit (sabbatical?) at Xerox PARC
by one of the principals of Three Rivers Computer, much like the way Lilith originated from Wirth's experiences
there.
I believe that the original code name of the Perq was the
"PascAlto", referring to its obvious heritage, but with the
Now that I hadn't heard.
intent to base the software on UCSD Pascal rather than
BCPL.
Undoubtedly the Perq owes much to the Alto, as did every other
similar graphical workstation of that era.
Absolutely. But I am curious as to how similar they are. Do
schematics/Technical docs for the Alto exist anywhere? It would be
interesting to compare them with those of the PERQ.
-tony
11:25 a.m.
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-
bounces at classiccmp.org] On Behalf Of Tony Duell
Sent: Friday, September 17, 2010 11:00 AM
To: cctalk at classiccmp.org
Subject: Re: Diablo 30 disks and failure
There's plenty of documentation on the Alto on BitSavers -- Ian
--- On Thu, 9/16/10, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
Sure. It was Brian Rosen, I believe.
I wonder if it's a conincidence that the PERQ
POS
filesystem recovery
tool is also called 'scavenger' and that the PERQ
filesystem also stores
all the pointers at least twice so it's posisble to recover
from quite
bad disk corruption. Not that any PERQ had a dmountable
hard disk.
The Perq was the result of a visit (sabbatical?) at Xerox PARC
by one of the principals of Three Rivers Computer, much like the way Lilith originated from Wirth's
experiences there.
I believe that the original code name of the Perq was the
"PascAlto", referring to its obvious heritage, but with the
Now that I hadn't heard.
intent to base the software on UCSD Pascal rather
than BCPL.
Undoubtedly the Perq owes much to the Alto, as did every other
similar graphical workstation of that era.
Absolutely. But I am curious as to how similar they are. Do
schematics/Technical docs for the Alto exist anywhere? It would be
interesting to compare them with those of the PERQ.
20 Sep
20 Sep
6:21 p.m.
From: Tony Duell
Sent: Thursday, September 16, 2010 12:27 PM
> There's a reason the Alto file system had the
scavanger and was designed to
> be recovered...
I wonder if it's a conincidence that the PERQ POS
filesystem recovery
tool is also called 'scavenger' and that the PERQ filesystem also stores
all the pointers at least twice so it's posisble to recover from quite
bad disk corruption. Not that any PERQ had a dmountable hard disk.
The ITS ("eye" "tee" "ess", never "it's")
operating system for the PDP-10
also has a filesystem component called the scavenger, and there's unlikely
to be much influence between that and the Alto/PERQ. It's kind of an
obvious name, isn't it?
Rich Alderson
Vintage Computing Sr. Server Engineer
Vulcan, Inc.
505 5th Avenue S, Suite 900
Seattle, WA 98104
mailto:RichA at vulcan.com
mailto:RichA at LivingComputerMuseum.org
http://www.PDPplanet.org/
http://www.LivingComputerMuseum.org/
6:30 p.m.
The ITS ("eye" "tee" "ess", never "it's")
operating system for the PDP-10
also has a filesystem component called the scavenger, and there's unlikely
to be much influence between that and the Alto/PERQ. It's kind of an
obvious name, isn't it?
Rich Alderson
Vintage Computing Sr. Server Engineer
Vulcan, Inc.
505 5th Avenue S, Suite 900
Seattle, WA 98104
mailto:RichA at vulcan.com
mailto:RichA at LivingComputerMuseum.org
http://www.PDPplanet.org/
http://www.LivingComputerMuseum.org/
Didn't the Perq scavenger have a vulture cursor? I vaguely remember that.
(I did our first data sheets on he Perq with Metaform, printed on a Xerox
2700? laser printer)
Peter Wallace
11:30 p.m.
On 9/20/2010 6:30 PM, Peter C. Wallace wrote:
Didn't the Perq scavenger have a vulture cursor? I vaguely remember that.
(I did our first data sheets on he Perq with Metaform, printed on a
Xerox 2700? laser printer)
Peter Wallace
Yup: http://yahozna.dyndns.org/projects/PERQemu/scavenger.jpg
The "garbage" on the screen is simply the memory of Scavenger as it
runs; the window size is reduced so that Scavenger has more memory to
run in on low-memory systems. (It also doubles as a progress indicator
of sorts...)
- Josh
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