Questons and discussion about the iMac.

101 responses total.

How does one use the iMac with "old" peripherals, such as serial printers,
serial/Appletalk networks (to "old" Macs), and SCSI devices? It does not
have ports for these, but instead the new USB port.

My latest "MacMall" catalog (which still gets sent to me from a single
purchase 3 years ago) has a couple odd USB items, including a serial port
cable and a parallel port cable for running legacy devices.  

"legacy devices"? meaning, stuff you aren't willing to throw out? I saw
some peripheral "translators" from other manufacturers that implied that
they would interface "old" serial devices, but nothing about SCSI or AppleTalk
compatibility. Also, the MacMall catalog does not give very specific
information about uConnect and EtherMac iPrint - e.g., how many ports do
they provide? 

I just realized that the iMac does not have a floppy drive! The only plug-in
offered by MacMall is the Imation SuperDisk (which handles 3.5" HD disks
as well as 120MB proprietary disks (not ZIPS, and much more expensive). 
The iMac appears to be primarily an internet machine, even with all of that
G3 computing power. 

The iMac must be reviewed thoroughly somewhere on the web - any suggestions?

  Check out some of the Mac publications, like MacUser, and MacComputing.

I did a search in AltaVista on <iMac +review> and got the straight dope on
http://www.enproindia.com/macguide/imac.html

It is as I concluded. I agree with the reviewer that it would be a *computer*
too if some features were dropped and standard ports and a floppy drive were
added. As it is, you have to spend a great deal more for peripherals and
USB adapters to use it as a *computer* with most existing devices.

Apparently someone called Newer Technology is bringout a USB to floppy
drive with two DMA serial ports - but not yet available.

After some costing, it appears cheaper to get an iMac plus the adapters
for older peripherals (and floppy) than to buy an equivalent G3 desktop
with separate monitor. Therefore the iMac still 'lives' as a potential
student's machine.

The iMac has a 10/100 BASE-T Ethernet port. Our current desktop has both
AAUI and 10 BASE-T Ethernet ports. Therefore, at least initially, the
latter could be used as the "floppy" for the former. But I don't know
anything about 10 BASE-T hardware and cabling. What would be required
to network the two machines via their Ethernet ports (simplest and most
economic - and no other machines on the network)? 

I guess I should also ask if this would work in loading software to the
iMac from applications on many diskettes - I'm not sure how it would work
when the installer calls for "Disk x". 

You would need an ethernet cross over cable.  You can make this yourself from
whatever length you need of cat 5 4 pair UTP cable, and two RJ45 plugs.  For
more than two computers, you would need a 10 base T hub, which would be around
$30.

Just plug the two computers together? What would the cross-over cable
wiring be? What does "cat 5" and "UTP" mean? And....would this provide
simple software installation across the net (and maybe even printing
to a serial printer)? [I do understand I would not be able to use this
to print to an AppleTalk printer, as a choice must be made between
AppleTalk and Ethernet.]

Ah hah! I have found 10Base-T cables for less than I can make them (Roger's
Systems Specialist). There are the ordinary cables and there are "crossover
pier to pier" cables, which I what I guess you mean. Is "crossover" like
a RS-232 null modem? I presume the ordinary cables are 'data' cables, with
all wires connected by the same numbers at each end. So, do 'crossovers'
flip some of the pairs? I would need a crossover longer than 25 feet, so
can I use an ordinary cable and a crossover cable connected by a RJ-45
modular coupler (I ask because I have seen RJ-11/12 modular couplers
that are "data", by the numbers, or "straight through". [One is called
simplex and the other duplex, but I can't remember which is which.]

Ordinary cables are straight through.  Crossover cables flip a couple of the
pairs (I have the pinout somewhere, if you want it, but I think it's at work
so it will have to wait until Monday).  Yes, you can combine a straight
through cable and a crosover cable to get a crossover.  You can also combine
two crossover cables to get a straight through (yes, I've had to do that. 
Don't ask).

Oh, and to follow up on #9, UTP means unshielded twisted pair.  UTP cables
come in a few different categories, I think numbered from one through at least
5.  In general, cat 3 is the low grade stuff that you can use for phone lines
over short distances, while Cat 5 is the good stuff that gets used for
ethernet, T1, etc.  Cat 5 costs more than Cat 3.

Category 3 is good enough for Ethernet 10 base T, but Cat(egory) 5 is what
is being installed mostly because it will handle the 100 Mb protocols.

"Pier to Pier" networking?  ;)
Did you know that "BNC" (the coax connector used in 10 base 2) means "British
Naval Connector"?

 Rane, did you buy an iMac?

If the iMac does take off, I predict a fair number of (relatively) inexpensive
"hook up your legacy stuff here" peripherals to be made by the third-party
companies.  

The SuperDisk is about the same price per Mb as the Zip disk.  Both are still
overpriced for the media.

I'd guess that the iMac is (once again) a bit ahead of its time.  With cheap
peripherals still not available, the early users are going to have some extra
expense and trouble getting real work done (as usual with any technology),
but long term... maybe you have your house wired for networking all the PCs
together, and a master print server unit that runs the printer, reads/writes
removable media, and connects your house to the Internet, and then all the
kids have an iMac in their rooms.  From that standpoint, the lack of
peripheral makes sense.  Sure, it would be nice to have the floppy right on
the machine, but then you don't have an ice-maker and water tap in every room,
do you?  I use removable media maybe once a week, so walkign down to the home
network toaster to do it wouldn't be a big deal.

I don't remember the last time I used a floppy disk for anything other than
an emergency boot disk on a system that wouldn't boot on its own.

What does the iMac do if its boot disk gets screwed up?

What does Grex do, for that matter?  Probably a ROM monitor that can read from
a CD-ROM, just like Grex.

The iMac has a built in 24X CD-ROM drive. 

I don't have an iMac but am considering getting one for my daughter's
birthday. She needs her own computer for school work. The iMac, even with
having to buy peripheral interfaces, is cheaper *and uses less desk space*
than a desktop CPU plus separate monitor and would be more portable if
she took it off to college. Students exchange lots of information on
floppies, and even hand in their work on floppies, though more of that
is being handled via the web. 

But, how well will it work to install software on the iMac via the
10Base-T link from a floppy drive on a PowerMac? I think I had problems
trying to do this over Appletalk/PhoneNet. I suppose it depends on whether
the installer gives the option of installing on a networked drive. [These
questions are motivated by the dumb choice I made a couple of years ago to
buy Microsoft Office 4.2 on floppies and not a CD-ROM.  I just opened the
install disk for the application, and did not find a way to choose the
drive on which to install the program.]

Ah, I hadn't realized it had a CD ROM drive.  In that case, I wouldn't have
much use for the floppy drive.

At this point, with dorms at many schools wired for ethernet, and students
who don't have teh ethernt connections often having good dial-up net
connectivity, I would assume students have other ways of exchanging file
without having to pass around floppy disks.  Whether they're using the
networks for that or not, I don't know.

You should look at the specs. The iMac also has a built in 56 Kbps modem,
10/100Base-T port, 2 12Mbps USB ports, a 4 Mbps IrDA port, 4 GB HD, and
233 MB G3 processor (among other stuff). 

That reminds me.  I still need to help Rane fix his SE...

I'd like that, but your house constructions comes first. We'd still have
use for the SE (like I still use my XT). Can't have too many computers...

I've ordered an iMac, and now trying to find the 10Base-T cables or the
parts for making them. The information about this I've gotten here is
more useful than any books I have - which don't describe the nitty-gritty
of cables and connectors. I did discover that 10Base-T uses only two (2)
twisted pairs, on the 1-2 and 3-6 RJ-45 connector contacts, but I'm
not sure what the positions are for reversed (crossover) cables. Couplers
are another story. I'd be glad to make the cables, but it is very unclear
what UTP cable works in which style RJ-45 connectors, and how to wire
a crossover cable. Maybe a 5-port hub for $40 is the way to go...then I
could have another box with nifty flashing lights, like in Star Trek...

10BaseT uses only four wires, but it's easier to use eight conducter cable,
and just wire it straight through, than it is to think about it.

For crossover, the pinout is:
1 -- 3
2 -- 6
3 -- 1
6 -- 2

Thanks! (I didn't guess that.)  What kind of mod conn does 8 cond Level 5
UTP cable go into: for "round solid cable" or for "flat cable"? This might
just be the economical way to go (if the crimper isn't too expensive).
Then, if I add a third computer, I'd just need a hub.

Twisted pair cable is round, not flat.  I've always just gone into a computer
or telephone supply store and asked for RJ-45 cable ends, and they've known
what I've wanted.  I tend to use the same cable ends on round and flat cable,
and they work for both.

Yep, all the 10BaseT stuff around here is round cable stuffed into flat
cable connectors.

What is the standard color coding/pin# for 10Base-T cables?

I can never remember.  As long as both ends match, the cable will work.

OK, then - what are the colors for each twisted-pair? (Have to identify
those, I would presume).

Twisted pairs are usually like blu & wht with a blu stripe or ring, red
& wht with a red stripe or ring, etc.  It's quite obvious when you remove
the sheathing from the cable.

Hold the RJ-45 end with the contacts away, cableend near you.  Clip on the
bottom, window up.  Wires should be from left to right:
Orange Strip
O
Green S
Blue
BS
G
Brown S
Br.

Then when you make a crossover you swap the oragne and greens on one end of
the cable.
GS
G
OS
B
BS
O
BrS
Br
  
I'm willing to answer questions or help if someone wants.

Thanks! 

I made up the cables, bought a cheap hub, and my Macs are talking. I have
more questions related to both: 

I used Level 5 UTP network cable with solid wires (the only kind Roger's
sells) and flat RJ-45 plugs. The first one took some time to line up all
the wires and get them straight and pushed into a plug. It helps a lot to
have them arranged flat far enough back so the plug grip is on the aligned
and flattened group of wires. My question is, how are RJ-45 plugs for
"round solid cable" different (they cost more), and when is *stranded*
network cable used (which I noticed was available in another catalog). 

On Macs you can't run Appletalk and Ethernet simultaneously, even though
they come out different ports, with the one exception of printing on a
Laserwriter with Localtalk with an application called Laserwriter Bridge,
which can network the Laserwriter. I can also print on a local serial
printer with Ethernet chosen, but cannot across the net. There used to be
an Apple LocalTalk Bridge app, but it has been discontinued and is
unsupported. I am now printing from the iMac by transferring the file to
the PowerMac and opening it there to print on the serial printer.  Is
there some way to print directly from the iMac across the Ethernet link to
either the Localtalk (Deskwriter 540) or serial (Stylewriter 1500) 
printers? My UM guru says NO. I find that hard to believe. 

I mentioned the iMac was for our daughter. She loves it and is already
making remarks about our plodding PowerMac 7200/120... 8^{.

The iMac replaces a (B&W) MacSE that she used until it broke down. I went
back and looked at what the SE cost: ca. $1,800 *plus* $520 for an
external Rodine 45 MB HD *plus* $250 for a 1 MB (!) RAM upgrade. That adds
up to just about TWICE (in 1987) what an iMac costs today (with a 'free'
RAM upgrade to 64 MB that I had to install myself). There is a revolution
occurring. 

I've learned of the Asante "Asante-Talk" adapter, which couples Ethernet
and LocalTalk nets ($100). This would let both the iMac and PowerMac print
to the Deskwriter. Does anyone know any limitations in its operation? It
is advertised as though it will transparently put Localtalk and Ethernet
devices on one net, accessible through any of the computers on the net,
and allowing easy file transfer. This would also release a printer port on
my PowerMac for other applications.

I'll find the answer to the above soon enough, as I have ordered an
AsanteTalk (Asante assured me it would do all I expect...). By the way, I
ordered it from AccessMicro, who had the lowest price (and what I consider
one of the nicest and user friendly web sites). 

Now, another NET matter enters: backup of the iMac. I upgraded from
DiskFit Direct to Retrospect Express (both Dantz) for backups. (This,
incidentally, actually saved money - by backing-up this PowerMac with
Retrospect, which compresses, I recovered 4 out of 12 ZIP disks, worth
more than the upgrade cost.) Anyway, I can apparently mount the iMac
volume on the PowerMac disktop, and then just run Retrospect on it - I
think. Is there any problem with backing up this way and, more important,
in restoring? The online manual got into some intricasies about
changing/not-changing Users&Groups, or some other intricasies that can
arise. 

I know I am all alone talking to myself, but I like my own company, so I
will inform myself that the AsanteTalk works a charm. Everything is now
connected. The iMac and PowerMac talk on Ethernet while a Powerbook talks
and listens with both on LocalTalk. They all print to a Deskwriter on
LoalTalk, and also to a Color Stylewriter on the printer port of the
PowerMac when the latter is on. Now, just need to get a ThinkPad into
the party.......

Still contemplating the Retrospect backup of the iMac across the ethernet.

You're just WAY to current for me, Rane.

Say, I could add that SE to the net, if you'd have time sometime to look
at the monitor. :)

- Backtalk version 1.3.30 - Copyright 1996-2006, Jan Wolter and Steve Weiss