"Douglas H. Quebbeman" <dquebbeman(a)acm.org> wrote:
> The emulator community is vigorously using a tape image container
> format known as TAP for precisely this purpose.
>
> Each record from tape is written to file prefixed *and* suffixed
> by a four-byte record length in little-endian format. A zero-
> length record is represented by a 4-byte value of zero; although
> intuition might call for 8-bytes (a prefix & suffix with nothing
> in between), this is not the case. The convention appears to come
> directly from FORTRAN 77's handling of unformatted sequential files.
>
> And EOF is represented by two consecutive zero-length records.
Thanks, I've been curious about this spec for a while and had little
luck turning up a concise description of the format.
One question, if I want to write multiple consecutive EOFs (I'm
thinking of classic HP3000 MPE :STORE format tapes here) do I write
two zero-length records for each, or do I "compress out" the
zero-length records in the middle? Say I want to write two EOFs,
do I write {0,0,0,0}, {0,0,0,0}, {0,0,0,0}, {0,0,0,0} or
{0,0,0,0}, {0,0,0,0}, {0,0,0,0}? I'm hoping it's the former.
-Frank McConnell
> From: Chris
>
> >I have tried to hit command-pretzel-o-f at bootup
>
> Control-Command-O-F (the pretzel/cloverleaf/open apple is the command
> key).
>
> -chris
>
Actually, that's probably a tongue-in-cheek reference to the shape
of your hands, when you try to hit those key combinations when starting up
the Mac...
--
--- David A Woyciesjes
--- C & IS Support Specialist
--- Yale University Press
--- mailto:david.woyciesjes@yale.edu
--- (203) 432-0953
--- ICQ # - 905818
Mac OS X 10.1 - Darwin Kernel Version 5
Running since 01/22/2002 without a crash
>Now, first, let me ask: Might the control panel not function properly
>if it's not in the "control panels" folder? I've just got it setting
>around on the drive, but it _seems_ to work. Not that I can actually
>see the "open firmware" stuff to make sure it's actually doing anything.
If the control panel loads anything at startup (which I would guess it
might), then no, it will NOT work under OS 8 unless it is in the control
panels folder (and you have rebooted). But not all control panels load
anything, many just change settings read from someplace. Those kinds need
not be anywhere in particular. (but since you are having problems... toss
it in the CP folder anyway)
I assume you researched it already, so I won't get into asking if you are
sure the 7200 will go into open-firmware. I thought it predated OF. I
didn't think they started that until PPC's... but I'm not really sure
(and seeing as the 7200 is PCI, it is a good candiate to be an early unit
with OF).
>I have tried to hit command-pretzel-o-f at bootup
Control-Command-O-F (the pretzel/cloverleaf/open apple is the command
key).
-chris
<http://www.mythtech.net>
> From: Christopher Smith
> --..
> I've been trying really hard to get the thing to give me an
> "open firmware" prompt, but have had no success.
>
> Right now I have a "converted" vga monitor plugged in, a Mac ADB
> keyboard/mouse, and an IBM terminal connected to the "modem" port,
> set to 38400bps, 8 data, 1 stop bit, no parity. The cable has
> been used recently on a SPARC, so I'm pretty sure it's good.
>
- Have you tried setting the terminal at 9600/8/n/1? That seems to
work for about everything, assuming someone hasn't changed the default
settings...
> .....
>
> Now, first, let me ask: Might the control panel not function properly
> if it's not in the "control panels" folder? I've just got it setting
> around on the drive, but it _seems_ to work. Not that I can actually
> see the "open firmware" stuff to make sure it's actually doing anything.
>
- I believe it has to be in the Control Panel folder to work properly,
and reliably...
- Which makes me think, and yes my question here it OT, so reply
directly... My OS X G4 has a modem port, but no other external serial
ports... (those bastards at Apple! :) Is there a way to hook up my VT420 to
it, so I can log into Darwin? Maybe using an external modem hanging off of
the VT420?
--
--- David A Woyciesjes
--- C & IS Support Specialist
--- Yale University Press
--- mailto:david.woyciesjes@yale.edu
--- (203) 432-0953
--- ICQ # - 905818
Mac OS X 10.1 - Darwin Kernel Version 5
Running since 01/22/2002 without a crash
Ok guys,
I'm pretty sure this isn't quite on topic yet -- but it is
somewhat old for a PowerPC model.
I have a 7200/75 which was given to me because it had a
problem with its video. I cleaned the mainboard with isopropyl,
and got all of the dust bunnies out, and it's worked fine since
then. :)
I've been trying really hard to get the thing to give me an
"open firmware" prompt, but have had no success.
Right now I have a "converted" vga monitor plugged in, a Mac ADB
keyboard/mouse, and an IBM terminal connected to the "modem" port,
set to 38400bps, 8 data, 1 stop bit, no parity. The cable has
been used recently on a SPARC, so I'm pretty sure it's good.
I have tried a Wyse-50 terminal, too, which I know is good.
(However, I'm not completely certain that the IBM terminal works
as I imagine -- I have it in ADM5 emulation mode right now. I
may try to put the Wyse back on it.)
I installed OS 8.1 on the disk yesterday. I got it to fit in
a 50M partition (barely -- what ever happened to being able to
fit MacOS on a floppy?), and I got a copy of the "boot variables"
control panel.
I have tried to hit command-pretzel-o-f at bootup. It works, but
the screen just stays black, and I can't get anything from the
terminal. I have tried with and without a null-modem adaptor,
since I'm not sure which way the serial port goes.
I also tried setting the input device and output device with the
"boot variables" control panel. I've tried:
Input: ttya
Output: ttya
Input: kbd
Output: screen
Input: kbd
Output: /chaos/control
Now, first, let me ask: Might the control panel not function properly
if it's not in the "control panels" folder? I've just got it setting
around on the drive, but it _seems_ to work. Not that I can actually
see the "open firmware" stuff to make sure it's actually doing anything.
Next:
Any ideas what I'm doing wrong? Has anyone else ever gotten this to
work?
Eventually I want to install Darwin on this system, and use the terminal
on the "modem port" for all console operations.
Chris
Christopher Smith, Perl Developer
Amdocs - Champaign, IL
/usr/bin/perl -e '
print((~"\x95\xc4\xe3"^"Just Another Perl Hacker.")."\x08!\n");
'
> -----Original Message-----
> From: Cameron Kaiser [mailto:spectre@stockholm.ptloma.edu]
> However, security through obscurity should never be
> considered optimal. :-/
Yep, I hope they're well configured, since the chance of a
security-problem-causing bug being cross platform among unix
systems is certainly there.
> Unfortunately, as Microsoft products make an inroad in the
> Macintosh market,
> this will eventually change. I see Mac owners running Outlook
> *without* a
> virus checker, and I just cringe and hug Elm tightly.
Anybody who runs outlook deserves what they get. Yes, that sounds
strange coming from me -- and it includes me. I fully expect that
this system -- poorly configured as it is with ridiculously
terrible software -- will some day catch a "cold." I will just
laugh and call in the corporate windows weenies when it happens.
"No my job. man."
That said, I am quite a bit more careful than the average person,
and maybe that helps.
Chris
Christopher Smith, Perl Developer
Amdocs - Champaign, IL
/usr/bin/perl -e '
print((~"\x95\xc4\xe3"^"Just Another Perl Hacker.")."\x08!\n");
'
> -----Original Message-----
> From: Chris [mailto:mythtech@mac.com]
> If BMW doesn't suit your fancy as an example, replace it with
> any small
> market share high priced vehicle. Like maybe the Lotus, or
> Lambrogini, or
> Ferrari.... or for more mainstream, the Jaguar. People aren't buying
> these cars because they need them, they are buying them
> because they WANT
> them.
I think BMW is a good metaphor for a Mac -- it leaves nicer cars
for the nicer workstations ;) Though, SGI isn't exactly what it
used to be -- maybe they just had some "bad years," the Octane2
shows some promise.
> bought out of desire, NOT out of neccessity. Once you have an
> audience
> that buys from desire, you can safely raise your prices to
> the highest
> point that audience will bear.
They'll like it better, of course, if you don't.
In the computer sense, people who know what they're doing will just
go buy an old Cobra, or that Lamborghini that's setting out in the
dumpster for some reason ;)
Chris
Christopher Smith, Perl Developer
Amdocs - Champaign, IL
/usr/bin/perl -e '
print((~"\x95\xc4\xe3"^"Just Another Perl Hacker.")."\x08!\n");
'
>The futurebus was short lived... as
>people say "it was in the future"... I never
>saw any REAL options for it...
DECnis used FB+, the DEC 4000-600/700 series
used the FB+ (although apparently a sufficiently
different version that interworking was
not possible) and that was about it,
at least as far as DEC was concerned.
Antonio
> And for the most part... this is perfectly fine with Jobs... he isn't
> interested in ruling the PC world, he is interested in making stuff
> people desire. He WANTS to be the BMW or Jaguar of the computer world.
> MS, Dell, Gateway, et al can be the Ford or Chevy, let them deal with
> having the bulk of the sales churning out the same old tired but reliable
> designs at cut throat prices.
Althought I'm no Jobs fan (hate Apple, love Mac), I must agree.
Well said, Chris.
In a message dated 5/2/02 9:33:25 AM Eastern Daylight Time,
erd_6502(a)yahoo.com writes:
> You misunderstand the direction I'm going. I have magtape with data
> already on it. I want to extract that data into a file or set of
> files on the disk that I can then burn to CD-R. I can use dd to move
> raw records, but I would like to also know what the block size was
> for a particular file so I could reconsitute the tape later if
> necessary. I'm not so worried about the VMS BACKUP tapes I need to
> spin off - I want one saveset per file. If I want to dup any install
> tapes (non-VAX), the blocking becomes more critical.
>
> Essentially, a physical backup that is primarily for data recovery,
> but secondarily for later restoration.
>
> I do not intend to use magtape as a primary backup media for Linux
> or Solaris. Writing tape is not a concern here, only reading. I
> do know how to operate dump/restore, tar, etc. They are of _no_ use
>
Wouldn't dd make an image preserving the original block sizes?
-Linc.
In The Beginning there was nothing, which exploded - Yeah right...
Calculating in binary code is as easy as 01,10,11.
