#Amiga 500 to Mac Hd
27 messages in this thread
All: I have a chance to buy a Mac external hard drive fairly reasonably
priced. What would I have to have to hook it up to my Amiga 500? What are
some potential problems I might run into? Any help would be greatly
appreciated. Thanks…/exit
Robert,
You should be able to hook up a Mac HD to your 500 with little trouble —
ASSUMING you have a scsi HD controller for your 500.
-sja
Steve,
I'm not so sure about that. A friend bought a Mac CD-ROM (SCSI) and we
can't get it to talk to ANY of our Amigas (3000, 2500 w/2090A, 2000HD
w/2091). I'm not so sure that Apple doesn't do SCSI 'different' from
other folks.
Vic,
I'm using a Syquest. The brand name on it is Total Peripherals. They are
a Mac peripherals company. All the software/doc that came with it are for
the Mac. I tossed all that, plugged it in, and it works fine.
Steve;
Vic is right. Many Mac drives will not work on Amiga controllers. Apple
does not do standard scsi. I have been talking with a drive software
engineer that has explained that C= is the only on in the 'home computer'
market that is doing scsi by the book.
I too have Mac Syquests running on my machines but it is more a credit to
Syquest than to Mac that they work (and when they don't you can usually
thank Apple).
-bill
Tossed it? Couldn't you find a deserving soul on CIS? If it weren't for
software for my Mac that came with another drive, I would have had to pay
for more software to run my Syquest…
John,
Yep, tossed it. I was afraid it'd contaminate the other disks it was
stored with.
-sja
Well, I give you all the assurance in the world that you can reformat Mac
720K disks in your Amiga drives. 🙂
John,
Yes you can. But, don't you worry about the Yuppie virus contaminating
the floppy head and spreading that contamination to Amiga formated disks?
grin>
-sja
Vic:
one thing to check for is to see if the drive responds to the SCSI reset
signal. Apparently the Mac send lots of reset signals when it's rebooted,
and that messes with many different drives, so to get around this they
jumper the drive to ignore the SCSI reset signal.
-Mike Schiller
In sunny Fort Lauderdale
I disagree – can you be more specific about why an Apple SCSI peripheral
wouldn't work on the Amiga? I think they certainly do. Who'd make a SCSI
device, call it SCSI, then it wouldn't work on pretty good SCSI like the
Amiga?
John,
I wish I could be more specific. SOMETHING was screwing up the SCSI
bus. I tried everything, adding it into an already existing chain, putting
it on the end by itself. HDTOOLBOX could NOT reliably report on ANY of the
SCSI devices (the names/versions kept getting trashed). WE even went out
and got one of the Apple 'feed-thru' type terminators, no luck. We simply
could NOT talk to the CD-ROM, and in many cases it interfered with using
any of the OTHER devices on the SCSI bus. I suppose I could go try to find
this device again to get the actual part # off of it, but looked like a Mac
CD-ROM, had the pretty multi-colored apple with a bite out of it (Appple
logo) on it. We spent WAY too much time trying to get it to work.
I've heard of people using Apple CD-ROM drives on Suns or Sparcs. I assume
this drive of yours was known to be working on a Mac. I don't want people
to take your suggestion the wrong way, the second half of my AmigaWorld
CD-ROM article just hit the stands and I don't want to defend your
statements. It's perfectly safe to buy a SCSI device made for a Mac and
use it on the Amiga. People do it all the time. I'd harbor a slight
suspicion that it was Apple's fault inside the drive, and not in their
SCSI.
John:
the drive mechanism inside the Apple CD-ROM is a Sony, and there are
problems with the Sony drives on the Amiga. I don't know all the details,
but there is some mention of this problem in the documentation for
CDROM-FS from CPR.
-Mike Schiller
In sunny Fort Lauderdale
Mike,
Yes, but that wasn't our problem. HdToolBox couldn't reliably get
device names (SOMETHING was loading/trashing the bus intermittently)
John,
Right now I have three SCSI devices in/on my Amiga, and two of them were
originally intended for Mac use…one of them is a CD Technology CD-ROM
drive (really just a Toshiba 3201 in a Mac-style case), as well as an
Apple/Quantum 40 meg hard drive…yup, it was supposed to go into a Mac,
has the Apple logo on it, as well as an Apple copyright for the firmware.
Both work great!
Jonathan
– via Whap!
John;
It is probably possible to find out just what it is about the Apple scsi
implementation this is so bad but why bother? It is and that is good
enough. I personnally found out when I bought a pair of 1/2 gig drives
and found that the bus was completely fouled up if one or more of those
drives was connected.
Contacted the maker, found out that the drive ROM was a MAC version ROM.
The explanation was that MAC scsi is non-standard. The same individual
explained that the company has purchased A3000's specifically because they
do comply with the scsi standards and thus provide an appropriate test bed
for new drive software.
-bill
So how does Quantum, Seagate, Conner, Maxtor, etc. all manage to sell
generic SCSI drives that work just fine on either a Mac or an Amiga? I've
bought a dozen different SCSI devices, and never has anyone asked me "which
computer is this for" unless they were trying to sell me cables and/or
software.
John,
I've got two different type of Conner CP-340's here. One set of
drives were removed from Mac's, the other set (I've got 3 of each type)
were removed from some AT&T mini's (they were used as paging drives for
UNIX).
Both are marked CP-340's, but the ones from the Mac only have 752
cylinders while the ones from the AT&T have 782 cylinders. The drive ID
jumpers are exactly reversed on the Mac drives from what one would consider
normal jumper settings. Jumper ON means binary 0 and jumper OFF means
binary 1 on the Mac type drives. The AT&T's use jumper OFF as binary 0 and
jumper ON as binary 1.
The AT&T's will do a low level format, while the Mac type won't;
although, both do return no errors on completion.
The AT&T drives work exactly as detailed in the Conner technical
manual I've got on them…the Mac drives obviously don't match the tech
manual in the above areas.
I did call Conner about the above…they told me that they made
special runs of the CP-340 for the Mac. They used special ROMs on them.
They also told me that Apple was the only one who required special
ROMs…everyone else just got plain jane CP-340s.
(Oh yea…those special runs were sold directly to Apple…not to
dealers)
Don
John;
I'll ask but I suppose that it is by designing to the lowest possible
common denominator and NOT following the scsi specs.
-bill
John:
I reciently bought a few Konica 5.25" 10 meg SCSI floppy drives from
Peripheral Land a large MAC accessory company, and several of the drives
had extra circuit cards added by PLI to make the drives compatible with
the MAC, and/or had the SCSI reset line cut. The Mac sends several reset
signals when it reboots, and the Konica drives (and several others I'm
told) can't handle getting many resets in a row. The Amiga on the other
hand sends only 1 reset per reboot as it should so the Konicas work fine
on the Amiga with the reset line intact.
I've also seen many MAC drives (not nessasarily Apple ones, but ones
designed to be added to a MAC) that were preset to a specific SCSI ID, and
I'm told that the MAC has trouble with certain SCSI ID's, or something
such as that.
Basically Macs aren't as SCSI compatible as most Amiga SCSI host adapters
are.
-Mike Schiller
In sunny Fort Lauderdale
Vic,
Sometimes pulling the RESET line (SCSI line 40) will get Mac
add-ons working.
Don
Don, Thanks…
Having worked on many Macs but being a novice to Amigas . . . .
1. You should always make sure you have the proper terminator on the
end of the SCSI chain. This prevents "reflected" signals from
stopping the boot.
2. You should never be cheap when buying your SCSI cable. SCSI is
flacky enough without poor cables.
MM
Mathew;
SCSI is hardly "flakey"! When compared to such drones as "MFM" and "RLL"
type systems SCSI is "a piece of the rock"! I have never seen or heard of
a situation where a properly set up SCSI drive that was connected to a
properly configured system and was moved to an identical system but did
not work.
It is true that there are a "bunch" of potential "pit falls." Not the
least of which are Macs and drives specifically designed to work with
Macs.
I routinely run Amigas and Unix stuff with multiple SCSI devices and even
multiple SCSI controllers. I have a mix of 50 pin ribbon cable, "Mac
round cable", berg connectors, blue ribbon connector and DB-25s. I move
devices between machine now and then. Other than severe problems with Mac
type drives, the only problems that I see are startup delays caused by the
system having NO idea of what the H*ll is going on! (where are the three
drives that were here last time and who are these new commers?)
This includes 8 different machines using seven different kinds of SCSI
controllers and nine different drive types from six different
manufactures.
-bill
Things will probably work ok (assuming that you have a scsi controller for
your amiga500) however, be aware that Apple does not follow the scsi specs
so there can be problems. The drive may not come up following a power up
or possibly even a reset without manual intervention. Also, it may not be
possible to add additional HDs with the Mac drive on the bus.
Personally, I would not buy the drive unless 1) It is a super good deal
and 2) if it will not work at all, the guy will take it back.
-bill