Seth J. Morabito wrote:
> Does anyone have any guidelines about making archival images of
> CD-ROM media? For years, I've been using dd on Solaris or Linux
> to dump the raw bytes of CD-ROMs, and cdrecord if I want to make
> a copy from the raw image, but I don't know if this is considered
> "good enough" to preserve all the associated filesystem and partition
> structures of the disc. It has been for me, so far, but I'd like to
> hear other opinions on the matter. How do you archive CD-ROM images?
As long as there's only one track on the CD, dd on Linux will grab
everything. On Solaris you might have to be careful to pick the right
device node so you grab the whole thing. On MacOS X you definitely have
to pick the right device node -- the one time I tried it, I picked
wrong and only got one partition.
Multi-partition discs usually have just one track containing all
partitions. If you want to be sure you can "cdrecord -toc", if there's
just one data track, you're good.
Some discs actually do have more than one track. The SunCD demo disc
is an example. It has a data track (probably with multiple partitions,
I don't remember) and a few audio tracks. Some combination of dd
(or readcd -- see below) and cdparanoia should be able to copy discs
like this.
I usually use dd, or even cat, on the first try reading a disc, just
out of laziness. But there's a program 'readcd' (part of the cdrtools
suite, IIRC) which is a little more sophisticated. In particular, if
a disc has a marginal sector or two, dd will give up, but readcd will
retry until it gets a good read.
Another note, if you are reading CD-Rs which were written in TAO mode,
you will get some empty sectors appended to the end, then an I/O error
as your drive tries to read past the leadout. But you're not actually
losing any data.
-- Adam
At 08:22 PM 10/26/2006 Ethan Dicks wrote:
>I used to use EBCDIC on a regular basis when I made HASP/3780/SNA
>gear... now, I think I can only remember 'space' and the numbers.*
Yes but do you remember good old BCD
Thanks
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please inform. Thanks.
I do have 2 PC4's in *very* questionable condition if
anyone is interested (for shipping). I'm primarily
looking for the color version of the 4.
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> Sent: Thursday, October 26, 2006 5:41 PM
> To: General Discussion: On-Topic and Off-Topic Posts
> Subject: TRS-80 Model 16
>
>
> I've got a TRS-80 Model 16 that I'm going to put on ePay, but I'd
> like to clean some of the grunge out of the half-height Tandon 8"
> diskette drives.
>
> In a nutshell, can someone tell me the easy way to remove these
> drives from the case?
>
Model 16 or 16B? The procedure is different.
If it is a 16b:
Remove slot access cover in back.
Turn the computer over (feet up)
Remove the 10 or so screws from around the case
Turn back over, being carefull to keep it together.
From the front of the unit, lift top shell and rotate left
the CRT stays attached to that piece of the case you lift up
You should now see the floppy cage on the right
Remove all the screws from around the cage and the two drives
should come out as a unit.
If it is the original 16:
Remove the two back screws from the case cover.
Remove this.
Remove all the screws from around the front (CRT)
bezel. It should drop off, with the CRT attached.
You should now be able to get to all of the screws
If this is an original 16, please let me know when you list it.
If you're interested in private sale, let me know. I'll send an offer
that you can either accept or ignore. I wouldn't even ask you to
clean the drives.
If you need it, I can scan in an exploded diagram from the two service manuals.
Kelly
I've got a TRS-80 Model 16 that I'm going to put on ePay, but I'd
like to clean some of the grunge out of the half-height Tandon 8"
diskette drives.
In a nutshell, can someone tell me the easy way to remove these
drives from the case?
Thanks!
Chuck
As long as we're talking about it; here are a few more ideas to
consider.
1. The Catweasel uses a selectable clock rate to obtain a clock
count that will fit in 7 bits. My gripe with this is that I have to
read a track or two (if different densities on the same disk) to
determine the correct clock rate. There's little worse than finding
out that you've guessed wrongly and your image is worthless.
If we're going to employ a dedicated MPU/MCU to handle this stuff,
why not go with a 10- or 11-bit clock rate and get rid of the rate
selection? One of the spare bits could be used for index detection
on hard-sectored disks.
2. Some drive diagnostics should be incorporated. Particularly with
5.25" drives, old sticky floppies can really drag the rotational
speed down. I'd really like to know that it's happening.
3. I can envision this device as a small box, powered by a wall wart
with an RJ-45 ethernet connector and on or two DC-37 female
connectors for drives. Given that this thing's going to be used for
all manner of drives, there's no compelling reason to provide drive
power as part of it.
4. DHCP is a nice feature, but not all vintage networks support it.
The option of a fixed IP address (192.168.x.x) would be a plus.
5. Should the box also supply the drive for older 8" drive 3-phase
steppers? How about the head-load signal?
That's it for now--I'm sure I'll think of something else!
Cheers,
Chuck
Looking for a WANG 2200 MVT system or
anything that will read Wang 5 meg removable platters;
8 inch floppy drive also needed; have many of the
Wang terminals but a spare mpu might be nice.
Thanks
John
WB6BLV at inreach.com
For collectors of arcana out there, I've listed an Intel bubble
memory development kit on ePay:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=320042426869&ssPage
Name=ADME:L:LCA:US:31
I never got around to using it--after I discovered the power
requirements of the thing, I moved on to battery-backed SRAM instead.
:)
Cheers,
Chuck