I bought 6 of these chips about 8 or 9 years ago, IIRC. However I have
exhausted all of my resources to identify them at the moment.
I would like to know what they are. The numbers are:
IDT 7M624
S45C (Delta symbol)
8738G1
Pretty chip, 8 gold caps mounted on a large purple ceramic substrate. 40 pin
wide DIP. 7/8 inch by 2 7/16 inch in size, large like a 68000 but not as
long.
Pictures at:
http://members.aol.com/innfogra/idt624a1.jpghttp://members.aol.com/innfogra/idt624a2.jpg
Paxton
Astoria, OR
Hi!
Now that my pdp11/44 is talking to me (switched from current loop to rs232),
i'd like to use it, of course. But i'm missing a unibus-terminator. Does
someone have a spare one ? i do have some cards (unibus and qbus) to trade...
btw. i live in Belgium / Europe.
Or is there a way to make a unibus-terminator, AFAIK they only contain
resistors.
Did someone do this before, or maybe someone has scematics of a terminator ?
regards,
lothar.
--
GMX - Die Kommunikationsplattform im Internet.
http://www.gmx.net
> From: Raymond Moyers <rmoyers(a)nop.org>
> To: classiccmp(a)classiccmp.org
> Subject: Re: Tape dumping programs for Unix/Linux...
> Date: Thu, 2 May 2002 21:56:13 -0500
> In-Reply-To: <000501c1f245$6a304ca0$1aefffcc@Shadow>
>
> You really have me going about the 9 track behavior tho
> null portion of tape as record delimiters "crap in the gap"
> problems of the past, and other such things.
>
> So far what ive learned about those things is nothing as
> many years around this stuff conditioned me to expect.
>
> If i spool the whole raw tape using a driver that knows
> nothing of any null gaps and simply spool all bytes that
> are bytes to a file .... could not i then pull the desired content
> out of the spool if i knew the format of the data ?
>
> If random access is what they are doing, how did they deal
> with a rewritten record, pad the unused portion of the record
> to overwrite trailing garbage ? or was the bytecount in a rewritten
> headder so that the controller knew the valid byte count ?
By its physical nature, a magtape is a sequential-access device.
One can of course keep track of position on the tape and use it
as a "random-access" input device. Standard magtapes as block-replaceable
devices were not at all common, and were really sort of a stunt,
"see what I can do" phenomenon.
> a tape with blank as delimiter/filler and records with no or
> painfully terse descriptors seems to me very .... um something.
That's the way it is when hardware is not very clever. Back in
the olden days. However, the record mark delimiter was more sophisticated
than just blank tape. It was actually a pair of characters surrounded
by blank tape, a two-character record, that could be detected by
analog circuitry.
carl
> From: Raymond Moyers <rmoyers(a)nop.org>
> To: classiccmp(a)classiccmp.org
> Subject: Re: Tape dumping programs for Unix/Linux...
> Date: Thu, 2 May 2002 16:37:30 -0500
> In-Reply-To: <200205021718.g42HI9X7086853(a)daemonweed.reanimators.org>
>
> On Thursday 02 May 2002 12:18, you wrote:
>
> > > Whats wrong with cat ?
> >
> > What's wrong with cat (and dd, and arguably the whole Un*x concept of
> > files-as-bytestreams for that matter) is that it loses information. A
> > magnetic tape is not an ordered stream of bytes, it is an ordered
> > stream of files of records, and each record has a length.
>
> Here you are talking about a data tape with fields that make up records
> where the records are all the same size and the fields being varaible
> length inside the record but repeating in all the other records.
>
> But a tape like this, from the days when tapes was used as random
> access devices is not the format of a system archive tape is it ?
>
> > So you are forced to result to multiple disk files to maintain the file
> > structure.
> > (which adds to your hassle because now you need to manage collections
> > of files instead of a single tape),
>
> Like with a tarball ?
>
> > and as you are copying the files to bytestreams you lose the record
> > length information.
>
> Unless you are going to resurrect some old general ledger program
> why is this important ?
For the same reason it is important to resurrect old computer hardware.
I thought that would be obvious to people who read this mailing list.
carl
--
carl lowenstein marine physical lab u.c. san diego
clowenstein(a)ucsd.edu
cat /dev/floppy > /test1
cat: /dev/floppy: Input/output error
-rw-r--r-- 1 root root 18432 May 3 02:09 test1
Bad floppy right ?
So time for dd, noerror tells it not to quit
sync tells it not to aggregate a short read with the good
ones, but to fill the remainder of the short read with zeros
so ...
dd conv=sync,noerror if=/dev/floppy of=/test2 ( bs=defaults to 512)
-rw-r--r-- 1 root root 1474560 May 3 02:18 test2
and we have the whole image of the proper size
but including bad sectors filled in with zeros
Raymond
> From: Raymond Moyers <rmoyers(a)nop.org>
> To: classiccmp(a)classiccmp.org
> Subject: Re: Tape dumping programs for Unix/Linux...
> Date: Thu, 2 May 2002 14:08:41 -0500
> In-Reply-To: <20020502200530.E35218(a)MissSophie.unixag-kl.fh-kl.de>
>
> On Thursday 02 May 2002 13:05, you wrote:
> > On 2002.05.02 18:25 Raymond Moyers wrote:
> > > Whats wrong with cat ?
> > [...]
> > > I see most are using dd when cat is all they need
> > cat(1) and dd(1) do not read / recognize the _physical_ block size of
> > the tape.
>
> At the portion of the work where you just want to get the stuff
> spooled to a file, you dont care about "block size" yet, you
> just need to get it pulled off.
>
> Unix will treat any device as a stream of bytes
>
> On my old sony, mkboot is broken, you cant use the OS to
> create a bootable volume of itself
>
> so ... you hang the old scsi disk off your linux box and
> cat /dev/sdb > /files/sonyhdimage.img
>
> hang the new scsi disk off your linux box
>
> cat files/sonyhdimage.img > /dev/sdb
>
> Put new disk in sony, look mom it boots !!
>
> Now you redo the disklabel and shove everything
> except root up to a new volume above the footprint of the old disk
> redo the middle volumes to suit ... move the stuff back down
> mount the new space as /usr/local whatever
>
> Now you have a 1g bootable disk in a machine that cannot create
> one for itself...
>
> Do you see what im getting at here ? hello ?
>
> and guess what ... i never even bother to involve myself with
> any "block sizes" even as the multiple volumes on
> that image uses a mix of logical block sizes.
Guess what. You aren't dealing with structured magtapes. And it's
a very rare disk drive that has a mixture of block sizes.
carl
--
carl lowenstein marine physical lab u.c. san diego
clowenstein(a)ucsd.edu
> From: Raymond Moyers <rmoyers(a)nop.org>
> To: classiccmp(a)classiccmp.org
> Subject: Re: Tape dumping programs for Unix/Linux...
> Date: Thu, 2 May 2002 11:25:19 -0500
> In-Reply-To: <5.0.0.25.0.20020502090947.02f88e30@pc>
>
>
> > At 02:01 AM 5/2/2002 -0700, Ethan Dicks wrote:
> >I can use dd to slurp
> >stuff off of tape, but it's tedious. What tools are people using for
> >tape archiving under Linux or Solaris? AIX seems to come with "tcopy"
> >that essentially pulls everything off the tape until logical or physical
> >EOT. I'm looking for something similar - point it at the drive and
> >siphon it on down.
>
> Whats wrong with cat ?
>
> use the /dev/nst0 device, its the one that dont rewind
> ( use mt commands for that kind of stuff )
>
> cat /dev/nst0 > file1.tap
> cat /dev/nst0 > file2.tap
>
> and so on
You have just thrown away all of the data structure on the tape.
No more clues about block lengths, file marks, etc.
Some original software is going to need that information to work
properly with whatever else is on the tape.
carl
--
carl lowenstein marine physical lab u.c. san diego
clowenstein(a)ucsd.edu
> Date: Thu, 2 May 2002 06:25:24 -0700 (PDT)
> From: Ethan Dicks <erd_6502(a)yahoo.com>
> Subject: Re: Tape dumping programs for Unix/Linux...
> To: classiccmp(a)classiccmp.org
> In-Reply-To: <Pine.LNX.4.44.0205021957030.15892-100000(a)floodland.tved.net.au>
> Sender: owner-classiccmp(a)classiccmp.org
> Reply-To: classiccmp(a)classiccmp.org
>
>
> --- cvisors(a)carnagevisors.net wrote:
> > there is also dump & restore, if the Sparc is running solaris there is
> > ufsdump and ufsrestore, and finally if all else fails tar
> > these programs should allready be (dump and restore) on the redhat box.
>
> 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.
Yes, that is what "copytape" was written for. Works quite well,
especially now that disks are (again) much larger than tapes.
The balance keeps shifting back and forth over the decades.
carl
--
carl lowenstein marine physical lab u.c. san diego
clowenstein(a)ucsd.edu
> Date: Thu, 2 May 2002 05:34:09 -0500 (CDT)
> From: Doc <doc(a)mdrconsult.com>
> To: classiccmp(a)classiccmp.org
> Subject: Re: Tape dumping programs for Unix/Linux...
> In-Reply-To: <Pine.LNX.4.44.0205021957030.15892-100000(a)floodland.tved.net.au>
>
> On Thu, 2 May 2002 cvisors(a)carnagevisors.net wrote:
>
> > there is also dump & restore, if the Sparc is running solaris there is
> > ufsdump and ufsrestore, and finally if all else fails tar
> > these programs should allready be (dump and restore) on the redhat box.
>
> I'd be very interested to know if RedHat dump/restore will fly on
> those magtapes. Linux' version only works on ext2 filesystems on the
> dump side, but since the tape archive (_IF_ it was generated by unix
> dump) isn't exactly a filesystem.... My bet would be a big no go, but
> now I'm curious.
> BTW, Jochen turned me on to the maketape utility from PUPS a while
> back. It works very well.
By their nature, dump and restore (or ufsdump and ufsrestore) are
operating-system specific. Dump in particular works on the raw disk
image and must have intimate knowledge of the way the operating system
constructs a file system.
On the other hand, I was once successful at restoring a dump tape made
on a MicroVax Ultrix system using "restore.old" on a NeXT. I was rather
astonished that it worked.
carl
--
carl lowenstein marine physical lab u.c. san diego
clowenstein(a)ucsd.edu
> From: Richard Erlacher <edick(a)idcomm.com>
> What's always annoyed me with "brand-name" PC's is that the packaging
ALWAYS
> deviates from the "norm" established by the DIY market. Consquently,
your
> DELL, Gateway, or Compaq was never upgradable, because the CPU or hard
disk
> wasn't supported by the BIOS, or some peripheral wouldn't fit in the
system
> because of address conflicts. Simple things like the on-board video
caused
> problems when they failed because one couldn't disable them, or, if one
did,
> the now-broken native video interfered with the replacement. Even
printer
> ports posed such problems. Many times the packaging itself was the
problem.
> Have you ever tried to replace or upgrade the CDROM drive in an HP PC?
Actually I've found that CD-ROM drives are among the easiest components to
replace in HPs. Often the floppy disk drives and power supplies have a
weird form factor, and when it comes to motherboards, forget it.
I have found HP and Compaq units where, in order to replace the CD-ROM
drive (or *any* drive) I had to pull the motherboard, which seems pretty
bizarre in itself.
Glen
0/0
> Date: Wed, 1 May 2002 19:52:05 -0500 (CDT)
> From: Doc <doc(a)mdrconsult.com>
> To: classiccmp(a)classiccmp.org
> Subject: Re: Googling and "egg-sucking" (was Re: "Toy" computers...)
> In-Reply-To: <3CD004D7.3282.A8CC01B@localhost>
>
> On Wed, 1 May 2002, Stan Sieler wrote:
> > and, re:
> > > Hey, guys. Simplify. A Google search on the phrase "suck eggs" leads
> > > to a clear explanation of the historical use of the phrase, dating
> > > back to the 16th century in English, and older in other languages.
> > >
> > > < http://www.quinion.com/words/qa/qa-tea1.htm >
> >
> > Nice try, but it doesn't address what I think most people are interested
> > in learning about (for that phrase, anyway :) ... sucking eggs.
> > It address, instead, the concept of teaching people something they
> > already know.
>
> Well, I dunno what most people are interested in learning about, but I
> know that referral to "teaching people something they already know" was
> the point of my original use of the phrase.
I thought people on this list were interested in historical stuff.
An investigation into the antiquity of the expression seemed appropriate.
On the same Web page one finds a much more antique version of the same
idea in Latin, which can be translated as "Don't teach a fish to swim".
carl
--
carl lowenstein marine physical lab u.c. san diego
clowenstein(a)ucsd.edu
> > The emulator community is vigorously using a tape image container
> > format known as TAP for precisely this purpose.
...
> Darn...sounds like a subset of what I use. I'd be interested
> in knowing more about TAP (with an eye towards adopting use of it),
> and would suggest some possibly missing features might be:
>
> - ability to flag if the current tape record had a recovered read
> error (obviously, not all hardware/OS's support getting that information)
No. And I see no useful purpose in including that in the format.
If the read was recovered, you have the data; surely you would
*not* want to recreate a tape and make a previously marginal
block, marginal again on a clone?
> - ability to flag if a particular tape record had a hard error
> while reading it
No (I can say this even though I'm about to ask): do you mean an
unrecoverable error, or one that was corrected by the hardware
(as opposed to being corrected by software)? Either way, if the
error was corrected, see my response above.
> - ability to flag if an End-of-tape marker/indicator was seen
> while reading the the current record (again, not all
> hardware/OS's support getting that information)
No, and again, I can't see how this data would be used to recreate
the tape or would be needed by an emulator. It's kind of like asking
if a particular hardware emulator also emulates memory parity errors
so that you can see memory parity errors in the logs. Why??
> - overall header at start of file, recording information about the tape
No, although I did consider suggesting some extensions like this.
One problem I have encountered with some old CDC tape formats
dealt with how blocking got handled. But my current feeling on
this is that if its blocked on taped, then the records will come
off the taoe with their proper lengths (I encountered this not
trying to read a tape, but trying to create an image of a tape
that no longer exists by a desctiption of its contents).
Anyway, I encode that kins of descriptive information (what kind
of computer, encoding, #tracks, etc) in the filename, or in the
name of the directory containing the file, or in a README.
> I have a program called "tapedisk", which reads an arbitrary tape
> and "copies" it to a single disk file (or set of files, if the size of the
> output file exceeds the maximum disk file size). The purpose of
> tapedisk is to allow a future exact copy of the tape to be recreated
> on another tape (of equal or larger size). (That future copy would be
> made with the companion program, disktape.) Additionally, most of
> my other tape-reading utilities know how to read a tapedisk format
> disk file as though it were a tape.
This sounds familiar... is it on the web somewhere?
> This is what I store on a per-tape-record basis:
...
So you really do want to recreate bad tapes as bad tapes...
Why?
> This is some what I store as a "header" at the start of the
> overall output:
...
Yeah, this info is README fodder... why on earth program that?
> As you can see...a lot of info, but all necessary to faithfully
> reproduce the tape later and/or to understand *why* the file might
> (or can't) be used to completely reproduce the tape.
Uh, again, can't understand why you'd need to recreate bad tapes.
As to the understanding, README.DOC... etc...
> This is part of a product we sell on MPE/iX systems, but I'd be happy
> to document the structures and/or work with other people on standards
> in this area.
>
> There's room for potential improvement. For example, is it worthwhile
> to have a table at the front of the output file that specifies where
> the first N EOFs are?
You just used that nasty, bad word "standard"... TAP is a convention,
not a standard.
;)
However, I'm not King of this Kingdom, we're a collective
(right out of Monty Python's Search for the Holy Grail).
You might try hooking up with the emulator community and
ask your questions there.
Regards,
-doug q
> From: Lawrence LeMay <lemay(a)cs.umn.edu>
> I could use some 2114's and C2109-4's. These are used in Teraks for Video
> memory and System memory. Just in case anyone knows of a source ;)
Jameco sells the 2114N for $1.49.
Glen
0/0
> From: Freek Heite <f.heite(a)hccnet.nl>
> On what kind of hardware is this MPM (86?) running? Newbies that want to
> experiment with MPM, would most likely want an implementation of MPM
for
> the IBM PC hardware - but is that available somewhere? The downloads that
> were mentioned a week ago (mpm8621i.zip etc.) are for some compupro
hardware.
Actually, I'd like to get MP/M for my Zenith Z-100s. Anybody know if this
is available??
Glen
0/0
> At 04:10 PM 5/2/2002 -0400, Douglas H. Quebbeman wrote:
> >No. And I see no useful purpose in including that in the format.
> >If the read was recovered, you have the data; surely you would
> >*not* want to recreate a tape and make a previously marginal
> >block, marginal again on a clone?
>
> Choosing between the loss of all the data, and a partial
> copy, I'll take the partial copy.
>
> I have many 8-inch disks with bad blocks. I'd like to preserve
> the data if at all possible. A simplistic 'dd'-style read
> won't preserve everything; it'll bail out when it has a problem.
???
I just did a 'dd' of a bad QIC-80 tape; it read the entire tape
as a single file, and didn't bail out.
I've not done that with magtape, but ISTR someone else here
saying that 'dd' does raw reads, bad blocks and all...
My bad if not true.
-dq
> However, if I notice recovered-reads (or hard errors) on old 9-track
> tapes, I often see fewer recovered reads (or hard errors) if I try
> the tape one more time. I assume that going over the heads once
> may have knocked off a bit of dust/dirt/something that affected
> the tape the first time. Note that I don't discard the
> results of the first run until the second run finishes...
hey! Me too!
> I've had one tape break during a second run :)
Ouch! Acetate backing?
> > > Go buy a 9-track drive and hang it on your *nix box.
> > > Let me send you a 9-track tape. You read it any way
> > > you want. You send me the tape back.
> >
> > > Then you go get a second tape, and put the data back on
> > > any way you want. Then send it to me, and I'll tell you
> > > if your technique works or not.
>
> BTW, the only way you can be *SURE* you got all the data on
> the tape is if *EVERY* read-request returned fewer characters
> than you asked for. E.g., if you did:
> bytesread = read(fromfd, buffer, BUFSIZE);
> and you get BUFSIZE bytes in, then there's a chance that that
> tape record had BUFSIZE + 100 bytes ... and you've just lost
> those last 100 bytes.
I *just* recently discovered this, and will incorporate that
into a utility I'll be hosting on the Prime.
-dq
SSP... Why, do you need a copy or something? I have it on 8" floppies... SSP
stands for System Support Program, FYI.
Will J
_________________________________________________________________
Join the world’s largest e-mail service with MSN Hotmail.
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This week has been a little slow and have to watch the cashflow.
1. 30 plus cartridges for the Intellivision (free)
2. hp 82901M Flexible Disc Drive excellent shape ($1.99)
3. IBM 3.5 FD external type 4865 ($1.99)
4. PowerBook 150 with adapter and case (Targus) ($20)
5. NCD ExploraPro x-terminal ($1)
6. Sun SPARCStation IPC ($1)
7. Two AppleCD 600e ($1ea)
8. Four AppleCD 300 ($1ea)
9. MicroScribe model 450/2013 ($1)
10.WYSE model WY-150-03-01 ($6)
11. TOMY robot ($1)
12. digital VT420-C2 (free)
13. AMT FormsWriter-242 (free)
14. AMIGA 500 (free)
15. digital VT240 model VS240-B ($8)
That's it for this week the balance is too new to post.
> Fair enough, but remember my post was about cat vs dd, and
> was not dealing with all these other issues being tossed
> up, it was to point out that what he was doing would be easier
> with a simpler tool
>
> It certainly didnt apply to preserving the information
> needed to rewrite a new 9 track tape.
>
> I think your being a bit rough on me here, your givin me
> a GI bath for things that was outside of the scope of my
> focus.
Ok, and fair enough... several of us detected that you might not
quite grasp the scope of the issue, yet your dogged assertiveness
was sending a different message.
I apologize for any part of my remarks that came off
like an attack.
Regards,
-doug q
Engineers are great- they're like laser beams.
They are intense and highly focusable.
.. and they bounce around the room until you don't
know which direction they're comming from.
Lee.
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> Keep in mind one thing: engineers who spend their lives working on tape
> hardware thought it was important enough to be able to signal recovered
> errors ... for a reason.
Engineers are great- they're like laser beams.
They are intense and highly focusable.
But they don't illuminate a wide area when focused.
OTOH, take the lowly, dim incandescent lightbulb. Not
intense. Not very focused. But it lights up the whole room.
Ok, now that everyone's got me pegged as the dim bulb in
this group... (didn't think I was going to leave that
one for someone else, did you?), let me finish my thought...
Anyway, my point is that sometimes engineers are so
focused that they don't see the big picture. But I'm
not disagreeing about the need to know about read
errors (or write errors for that reason).
Regards,
-dq
Stan sayeth:
> > No. And I see no useful purpose in including that in the format.
> > If the read was recovered, you have the data; surely you would
> > *not* want to recreate a tape and make a previously marginal
> > block, marginal again on a clone?
>
>
> NOOOO! It's *IMPORTANT* to know if there was a question about the
> accuracy of the data! That's *WHY* some tape drives even *tell*
> you there was a recovered error ... so the user could use that
> information!
I do that during the first dozen-or-so reads of the tape...
> It's like getting a recovered parity error on memory.
> Should you know about it? DAMN STRAIGHT YOU SHOULD!
heh... for years, any IBM compatible PC would, on detection
of a parity error, deliberately crash. Doesn't matter why,
I just lots my stuff...
> Without recording that information, you also can't answer
> important questions like: is the orginal tape in good shape?
Sure, *make note of it*, but I don't necessarily view the
image file as the only correct place to put that info. But
it's not a bad idea, just a bit Brobdignagian...
If I was Tim Shoppa and was doing analog reads of tapes so
far gone that you've got only one try to get it right, sure.
But like I said before, traditional methods shouldn't be used
on these tapes.
> > > - ability to flag if a particular tape record had a hard error
> > > while reading it
> >
> > No (I can say this even though I'm about to ask): do you mean an
> > unrecoverable error, or one that was corrected by the hardware
> > (as opposed to being corrected by software)? Either way, if the
> > error was corrected, see my response above.
>
> If it was corrected, then there was no error (other than a
> recovered read, already correct recorded via the earlier bit :)
>
> I meant a real, live, actual error. (E.g., missing oxide)
>
> When recording the contents of a tape it's **IMPORTANT** to know
> that there was an error there. If you simply skip the erorr and
> keep reading, you've lost data.
> Did you lose original user data? Possibly, and you've definitely
> lost data about the tape (i.e., the fact there was an error).
>
> By recording the fact an error occurred, along with any data
> your tape drive/OS *may* have sent you, you preserve the ability
> to act wisely in the future. For example, by recording the
> fact there was an error at megabyte 100 in a 102 MB file,
> the user would have confidence that when that file is eventually
> extracted, the first 99 MB of it is in fine shape.
Y'all must encounter a lot more marginal tapes than I do. The
ones I can't read have gone all the way down to where they will
require an analog read. If I can read it digital at all, I'll
reread the dang tape until I get ever record error-free. The
wet read is most useful in this application.
> > > - ability to flag if an End-of-tape marker/indicator was seen
> > > while reading the the current record (again, not all
> > > hardware/OS's support getting that information)
> >
> > No, and again, I can't see how this data would be used to recreate
> > the tape or would be needed by an emulator. It's kind of like asking
> > if a particular hardware emulator also emulates memory parity errors
> > so that you can see memory parity errors in the logs. Why??
>
> With 9-track tapes, software writing to the tapes generally watches
> for an indication that the end-of-tape marker (a short silver
> reflective strip) has been seen. At that time, it can prepare
> to do a reel-switch. Although some people feel they can backspace
> and write reel-switch info prior to the EOT marker on a 9-track
> tape, that's technically not safe (and opens up the possibility
> of getting what's called (in 1979) "crap in the gap"). Anyway,
> the ANSI (?) standard for 9 track tapes specifies a minimum length
> of tape be available for writing after the EOT marker ... a length
> that should be sufficient (even with modest multiple outstanding
> write-ahead requests) to write the reel switch information.
I think you're missing my point- I don't believe there are any
9-track drives that split physical records across reels of tape.
If I'm wrong, please correct me.
> On at least one OS, Burroughs MCP, one could detect that EOT at
> read time. Then, if one is doing multiple read-ahead requests,
> one can moderate them appropriately.
Yes, yes, yes, of course the EOT is detected while reading. But
it happens *between* records, not *inside* them.
> Ok...the short answer: it's information. You don't throw away
> information without a darn good reason. :)
Hey, if physical records *can* be split bwteen reels, then you
are absolutely right.
> > > - overall header at start of file, recording information about the tape
> >
> > No, although I did consider suggesting some extensions like this.
> > One problem I have encountered with some old CDC tape formats
>
> Sorry...if you want a professional program, not something like
> that toy cptape, you *WILL* have this information.
>
> Been there, worked on that, for over 30 years. Trust me...you
> *want* all the information you can get.
Actually, all I want is that the system software and applications
can use the data from the tape without detecting its coming from
some place other than a physical tape. So far that goal has not
required the extreme mesaures discussed here.
> > Anyway, I encode that kins of descriptive information (what kind
> > of computer, encoding, #tracks, etc) in the filename, or in the
> > name of the directory containing the file, or in a README.
>
> If two items of data are separated, what happens to them?
> Yep. Should be 'nuff said :)
Well, Raymond and I agree that tarballs work well for this, as
well as other such methods of encapsulation.
> > > I have a program called "tapedisk", which reads an arbitrary tape
> >
> > This sounds familiar... is it on the web somewhere?
>
> The MPE V version was/is (can't recall which), and was free.
> The MPE/iX version is a product from our company.
I was thinking of some Linux thing... I've only a few hours
of HP3000 experience. Looked like a nice extension of the
2000 Access system, at first...
> > So you really do want to recreate bad tapes as bad tapes...
> >
> > Why?
>
> No...I want to know that a problem existed, and where that
> problem was.
>
> Again...this is basic, vital, and indisputable. You *NEED* to
> know if there was a problem with the tape, and if you're trying to
> extract a particular file you need to know where any problems
> are in that file. Otherwise, you'll be lying to the user.
>
> If you know where within a file an error was found, then you've
> got a chance at recovering most of the rest of the data successfully.
> If you know an error occurred *somewhere* in a file, but not
> where, then you have a large pile of bits which *might* be trash,
> and *might* be useful ... but neither you or the user knows.
> And, if you don't know where the errors were (and how many there
> were), you can't reliably restore the data. That data might
> be banking information that your company is being audited on;
> it might be data that could clear someone of a crime...you simply
> don't know.
>
> Data is important...that's why we call it data and not junk :)
We're not disagreeing about this, we just have a different
time-and-place attitude about it.
> > This is some what I store as a "header" at the start of the
> > > overall output:
> >
> > ...
> >
> > Yeah, this info is README fodder... why on earth program that?
>
> Uh, 'cuz someone had to do it and build a reliable, thorough
> program?
I'm not arguing that it's of no value, but I'm looking at
cost of effort expended vs. return on investment. I used
to always believe in building for the worst-case, but these
days it's rarely feasible. The people writing the checks
don't want to pay for features they don't think they'll use.
> > > As you can see...a lot of info, but all necessary to faithfully
> > > reproduce the tape later and/or to understand *why* the file might
> > > (or can't) be used to completely reproduce the tape.
> >
> > Uh, again, can't understand why you'd need to recreate bad tapes.
>
> Again...you're *NOT RECREATING BAD TAPES*.
I understand. Recreating tapes from images is not a criterium.
> > You might try hooking up with the emulator community and
> > ask your questions there.
>
> This being ClassicCmp, I thought they might be here, too :)
One or two of us, at least!
> Besides, this isn't an emulator question so much as a data
> preservation question.
Related issues, to be sure, but not necessarily identical ones.
I don't think we're really disagreeing here; you circle
the block to the left, I circle to the right. We both
make it to where we want to go.
Regards,
-dq
> > There are/were apparently a number of Apple LocalTalk cards made
> > for PC usage. One of them is the PC MacBridge by Tangent Technologies -
> > now defunct - which is a short 8-bit card based on the Zilog Z8530APC
> > chip. A google search will disclose multiple others also.
>
> I have a native Apple LocalTalk ISA card manufactured by Apple. It does an
> excellent job and the PC communicates seamlessly with the Macs in the
> apartment.
Since the thrust of this topic is find a board that can be used
to do IBM BISYNC communication, would you happen to know what
chipset is used by the board? It would be hard to use it if
no one knows how to write software for it...
-dq
"Douglas H. Quebbeman" <dquebbeman(a)acm.org> wrote (after Stan):
> > - ability to flag if a particular tape record had a hard error
> > while reading it
>
> No (I can say this even though I'm about to ask): do you mean an
> unrecoverable error, or one that was corrected by the hardware
> (as opposed to being corrected by software)? Either way, if the
> error was corrected, see my response above.
This is useful -- if you are working with an only copy of a tape
and it is marginal, this lets you record in the recovered image
just which bits could not be reliably read.
I'm not sure if "recovered read error" has such uses. Stan?
Enlighten us?
> > - ability to flag if an End-of-tape marker/indicator was seen
> > while reading the the current record (again, not all
> > hardware/OS's support getting that information)
>
> No, and again, I can't see how this data would be used to recreate
> the tape or would be needed by an emulator. It's kind of like asking
> if a particular hardware emulator also emulates memory parity errors
> so that you can see memory parity errors in the logs. Why??
I can see some use for this if you want to use the recovered
image file with an emulator -- you can provide the physical-EOT
indication to the emulator. What's it good for? I don't know, but
I wouldn't be surprised if there is some software that relies on
seeing the physical-EOT mark while reading.
> Anyway, I encode that kins of descriptive information (what kind
> of computer, encoding, #tracks, etc) in the filename, or in the
> name of the directory containing the file, or in a README.
There is something to be said for keeping all the related bits
together in a single container, it keeps them from getting separated.
> However, I'm not King of this Kingdom, we're a collective
> (right out of Monty Python's Search for the Holy Grail).
> You might try hooking up with the emulator community and
> ask your questions there.
Where does one go to find "the emulator community"?
I don't think there is one, I think there are several, just like there
are at least two "TAP formats", both having to do with container files
for tapes, only one is for proper serial magnetic media like I think
we are discussing, and the other is for audio data cassettes on some
1980s bitty box (a Sinclair Spectrum I think).
Are they going to care? Should they, so long as there's a reasonable
way to down-convert a fancier tape container file format to their
flavor of TAP format?
-Frank McConnell
> > > - ability to flag if an End-of-tape marker/indicator was seen
> > > while reading the the current record (again, not all
> > > hardware/OS's support getting that information)
> >
> > No, and again, I can't see how this data would be used to recreate
> > the tape or would be needed by an emulator. It's kind of like asking
> > if a particular hardware emulator also emulates memory parity errors
> > so that you can see memory parity errors in the logs. Why??
>
> I can see some use for this if you want to use the recovered
> image file with an emulator -- you can provide the physical-EOT
> indication to the emulator. What's it good for? I don't know, but
> I wouldn't be surprised if there is some software that relies on
> seeing the physical-EOT mark while reading.
In my emulator, when I reach the end-of-file on the tape image
file while reading it, the tape drive emulation returns the
status code for physical EOT.
> > Anyway, I encode that kins of descriptive information (what kind
> > of computer, encoding, #tracks, etc) in the filename, or in the
> > name of the directory containing the file, or in a README.
>
> There is something to be said for keeping all the related bits
> together in a single container, it keeps them from getting separated.
Absolutely- that's why I ZIP or TAR and GZIP the directory
containing the image file(s) and a README.
> > However, I'm not King of this Kingdom, we're a collective
> > (right out of Monty Python's Search for the Holy Grail).
> > You might try hooking up with the emulator community and
> > ask your questions there.
>
> Where does one go to find "the emulator community"?
Well, each emulator has its own community, but many of the
players live in more than one, so that makes it more of a
"meta-community".
There is a mailing list for the SIMH people.
I run a mailing list for the Cyber Reimplementor's Guild.
I believe there is one for the Hercules crowd.
It would be nice if comp.sys.emulators could provide the
synergy to bring us all together. But it's saturated with
game system emulator talk, which draws too much attention
>from TLAs. Like I also wish the vintage computer department
would not list toys, but I digress.
> I don't think there is one, I think there are several, just like there
> are at least two "TAP formats", both having to do with container files
> for tapes, only one is for proper serial magnetic media like I think
> we are discussing, and the other is for audio data cassettes on some
> 1980s bitty box (a Sinclair Spectrum I think).
Darn I really should read all the way before replying...
Actually, yes, I noticed that someone is using a format for
casette tapes, and also called it TAP. How tragic, they
should not be confused with each other...
> Are they going to care? Should they, so long as there's a reasonable
> way to down-convert a fancier tape container file format to their
> flavor of TAP format?
Well, having a common format makes it easier to exchange stuff.
-dq
> At the portion of the work where you just want to get the stuff
> spooled to a file, you dont care about "block size" yet, you
> just need to get it pulled off.
>
> Unix will treat any device as a stream of bytes
And therein lies the problem.
...
> Do you see what im getting at here ? hello ?
No, I don't, because your entire example was disk-centric,
which simply doesn't apply to tapes. Tell you what... how
about an empirical test?
Go buy a 9-track drive and hang it on your *nix box.
Let me send you a 9-track tape. You read it any way
you want. You send me the tape back.
Then you go get a second tape, and put the data back on
any way you want. Then send it to me, and I'll tell you
if your technique works or not.
You game?
-dq
> > No (I can say this even though I'm about to ask): do you mean an
> > unrecoverable error, or one that was corrected by the hardware
> > (as opposed to being corrected by software)? Either way, if the
> > error was corrected, see my response above.
>
> This is useful -- if you are working with an only copy of a tape
> and it is marginal, this lets you record in the recovered image
> just which bits could not be reliably read.
I did mean to add that I saw *some* value in this...
-dq
> On Thursday 02 May 2002 14:51, you wrote:
> > > At the portion of the work where you just want to get the stuff
> > > spooled to a file, you dont care about "block size" yet, you
> > > just need to get it pulled off.
> > >
> > > Unix will treat any device as a stream of bytes
> >
> > And therein lies the problem.
>
> You would rather work the drive to death ?
When I break it, I fix it. I'm good at things like that.
> You know, any really old tape you are attempting to recover
> you really do not want to be running it thru the tape deck
> very much
For tapes that far gone, a digital read won't work. You have
to build your own drive and sample the analog data coming off
the heads using A/D and not using the digital-based discriminator.
For tapes not that far gone (like the ones of mine that spent
days under water and then months with stachybactris growing on
them), I have a wet-read technique that prevents most shoe-
shining.
> disks are huge these days, and the content is best messaged
> on a new disk rather than an old tape.
Agreed, *that's why the TAP format exists*, as well as Stan
Seiler's tapedisk/disktape system.
> > > Do you see what im getting at here ? hello ?
> >
> > No, I don't, because your entire example was disk-centric,
>
> Wrong i used it as an example, the raw stream already fit
> its intended destination in the hard drive case.
If the structure of what is on a tape depending only on the
bits written to tape you would be right. BUT IT DOESN'T!!!
Record marks on a tape are lengths of tape where NO BITS ARE
RECORDED. Your technique gets the bits, but misses the are-not-bits.
> > Tell you what... how about an empirical test?
>
> Well since we already know the behavior, we already know
> the results dont we ?
Dictionary Definition of "Empirical"
1.a. Relying on or derived from observation or experiment.
b. Verifiable or provable by means of observation or experiment.
Verification. Proof. Why not put your money where your mouth is?
> > Go buy a 9-track drive and hang it on your *nix box.
> > Let me send you a 9-track tape. You read it any way
> > you want. You send me the tape back.
>
> > Then you go get a second tape, and put the data back on
> > any way you want. Then send it to me, and I'll tell you
> > if your technique works or not.
>
> this is very predicatble if you know the raw behavior
> of the devices isnt it
>
> the whole idea was to point out some of this raw behavior
Crambe repitita.
-dq
Raymond Moyers <rmoyers(a)nop.org> wrote:
> > At 02:01 AM 5/2/2002 -0700, Ethan Dicks wrote:
> >I can use dd to slurp
> >stuff off of tape, but it's tedious. What tools are people using for
> >tape archiving under Linux or Solaris? AIX seems to come with "tcopy"
> >that essentially pulls everything off the tape until logical or physical
> >EOT. I'm looking for something similar - point it at the drive and
> >siphon it on down.
>
> Whats wrong with cat ?
What's wrong with cat (and dd, and arguably the whole Un*x concept of
files-as-bytestreams for that matter) is that it loses information. A
magnetic tape is not an ordered stream of bytes, it is an ordered
stream of files of records, and each record has a length. So you are
forced to result to multiple disk files to maintain the file structure
(which adds to your hassle because now you need to manage collections
of files instead of a single tape), and as you are copying the files
to bytestreams you lose the record length information.
This may come across as a flame of Un*x, and maybe it is, but really
my point is that the Un*x model of files as bytestreams is not an
appropriate model for magnetic tapes.
-Frank McConnell
>> Because people WANT a Mac. How does BMW get away with charging a price
>> premium when they only have a 5% market share. People will pay the price
>> because they want the item.
>>
>I wouldn't go there ... BMW's are infamous "hangar queens." Having worked in
>more than one group with several BMW owners, I've often driven people to the
>shop in my Maxima. One time I noted that every BMW needed a day in the shop
>every week. While I'm sure that was the exception rather than the rule, I'm
>sure I'll never covet one of the things.
Yes, but you are just re-inforcing my point. Sure YOU might never want
one... but despite the fact that they may be built like crap (I can't say
personally, but your experience seems to imply they might be), people
will STILL buy them. BMW is no where near worried they will go out of
business due to lack of sales. People will buy them, and they will pay
the higher price for them, and they will take all the good and bad that
comes with them, and do it with a smile... because they WANT one.
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.
That is what is going on in the Mac world for most of Apple's sales. They
are sold for no other reason than people want one. It might be because
they prefer the Mac, it might be because they think they look cool, it
might be because they hate MS... for most of the sales... it is simply
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.
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.
-chris
<http://www.mythtech.net>
> -----Original Message-----
> From: Fritz_Chwolka(a)t-online.de [mailto:Fritz_Chwolka@t-online.de]
> There is someone searching for infos about IMS - hardware.
> Can you help ?
> Answer only to:
They must really be serious about getting help with this. ;)
I count three emails about it so far -- or was that four?
Chris
Christopher Smith, Perl Developer
Amdocs - Champaign, IL
/usr/bin/perl -e '
print((~"\x95\xc4\xe3"^"Just Another Perl Hacker.")."\x08!\n");
'
> 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.
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.
I've got code samples I can throw at you in C, Modula-2, and F77.
Regards,
-dq
Is anyone on the list going to this hamfest?
Has anyone gone before? Is it worth a 90
minute (each way) drive?
The web page for it fails to mention what time
it starts or what it costs to get in.
Thanks.
> From: Chris
>
> >- 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?
>
> Get that Griffin G-Port if you aren't using the modem. It replaces the
> modem card and gives you a standard Mac RS-422 serial/localtalk port. I
> think they are about $40.
>
> Otherwise, what about a USB to Serial adaptor?
>
> -chris
>
The G-Port is a neat idea, but since I'm poor at the moment, and
have an external modem already, that's why I was thinking along that
route...
--
--- 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
>> >I have tried to hit command-pretzel-o-f at bootup
>>
>> Control-Command-O-F (the pretzel/cloverleaf/open apple is the command
>> key).
I'm glancing at that link for info of 7200 to Linux... and it mentions
the keys to hold are
Command-Option-O-F... not Control-Command-O-F.
I do however assume that you were already holding the correct keys, since
you said the screen blanked when you did it... but I figured it bears
pointing out just in case.
-chris
<http://www.mythtech.net>
>> didn't think they started that until PPC's... but I'm not really sure
>
>PPCs? If you mean PowerPC, I'm sure it's got a PowerPC core ;) But I
>assume you mean something else.
Yeah, I dropped the word "later" ("until later PPC's")... caused by over
editing what I wrote first, which was something along the lines of "I
didn't think they started doing OF until the later model 603e/604's that
came out around the time of the first G3s, in the era of motorola
clones".
And when I diced that down to simplify my statement, I diced a little too
much.
Sorry about that.
-chris
<http://www.mythtech.net>
> > 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.
My first attempt at understanding the format was wrong (see my
comment re intuition).
I would side with you on it being the former, but that's
my intuition speaking to me...
;)
> According to this link, it states that OF on the 7200 doesn't
>drive the display and that a serial cable must be constructed to
>access it by terminal. It doesn't give specifics on the connection
>though.
>
> http://homepages.ihug.com.au/~aturner/7200boot.html
>
> There are also other links there that may be useful. It
>looks like OF on the 7200 has quite a few bugs.
Hum... I happen to have a 7200 logic board sitting here on my desk. I
think the power supply is under my desk... maybe I'll hook them up and
see what I can get into.
-chris
<http://www.mythtech.net>
>- 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?
Get that Griffin G-Port if you aren't using the modem. It replaces the
modem card and gives you a standard Mac RS-422 serial/localtalk port. I
think they are about $40.
Otherwise, what about a USB to Serial adaptor?
-chris
<http://www.mythtech.net>
> -----Original Message-----
> From: Jeff Hellige [mailto:jhellige@earthlink.net]
> According to this link, it states that OF on the 7200 doesn't
> drive the display and that a serial cable must be constructed to
> access it by terminal. It doesn't give specifics on the connection
> though.
I have such a cable. As I said, it hooks a terminal into a SPARC,
with the same kind of port, perfectly well. For some reason I still
can't get OF to talk to me on the terminal (either with or without a
null-modem).
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]
> 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
I'm not sure, but most of the places I've checked seem to think it
has it.
> didn't think they started that until PPC's... but I'm not really sure
PPCs? If you mean PowerPC, I'm sure it's got a PowerPC core ;) But I
assume you mean something else.
> (and seeing as the 7200 is PCI, it is a good candiate to be
> an early unit
> with OF).
I've read that it was the first. With a version of 1.0.5 or something
like that. I also have a PDF from apple (specifically regarding the
7200 series) which says this:
The system software for the Power Macintosh 7200 computer includes the
following new features:
large partition support
Drive Setup
transport-independent networking (Open Transport)
Open Firmware startup
enhanced power management software
> >I have tried to hit command-pretzel-o-f at bootup
>
> Control-Command-O-F (the pretzel/cloverleaf/open apple is the command
> key).
.../splat.
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: David Woyciesjes [mailto:DAW@yalepress3.unipress.yale.edu]
> - 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...
Yes.
Chris
Christopher Smith, Perl Developer
Amdocs - Champaign, IL
/usr/bin/perl -e '
print((~"\x95\xc4\xe3"^"Just Another Perl Hacker.")."\x08!\n");
'
"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");
'