#CD-ROM software
33 messages in this thread
Not sure if this message got lost the first time, but here goes:
I've never had SCSI troubles bad enough to warrant buying an active
terminator, but it's solved the problems of many of my Mac friends.
You replace _one_ set of terminators with the active terminator. It then
analyzes the bus and sets up optimal termination parameters. (Don't know
how it works, but it does.)
_APS Technologies_ is the company name, and I've purchased several items
from them over the years. They're usually competitively priced, and
service & quality is high.
Their phone number is……
1-800-325-6316
The external 3501 has been on sale for $299 for a few months now, so you
might want to see of they've dropped their price.
Erik Flom
Thanks Erik…
Still have stupid question…
Does one then remove ALL the terminators on ALL the devices in the SCSI
string… and then stick the special terminator on ANY ONE of them, or does it
go on the last one ?
Is that right ? If not – what is the arrangement you should use on… say a
string of 3 devices…
COMPUTER -> Dev 1 -> Dev 2 -> Dev 3
All the best, HILARY.
Hilary,
The active terminator I HAVE, is a little tiny box, a little bigger than a
par or ser gender changer, with a 50 pin centronics connector. I had no
instructions but yanked all the terminators off the external drives and pluged
this end at the end of the 50 pin ribbon cable, I left the terminators on the 1
internal hard drive..
HD > gvp cont > HD > HD > CDROM > Syquest > Active terminator
^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Internal External
As this worked fine, I am a little anxious to try anything else, with scsi
I could put it back EXACTLY as it was and then not work until I have spent a
week with the covers off everhing and then it would mystericaly clear itself
up. <g>
..Steve
Cruising on Autopilot
from beautiful Coastal South Carolina
Thanks Steve for your notes and diagram.
Why does this "magic terminator" do a better job than just leaving the built in
terminator in the LAST of the SCSI chain, and removing the others? What
wonders does it perform?
Have seen a SONY (External) CD-ROM drive – double speed – with SCSI II.
interface, for a tad under $270.00. What do you think?
All the best, HILARY.
Eriks explanation made sense to me <g>, don't really know Hilary, but having
heard other wonder stories on active terminators, I decided to try it after
talking to daniel wolfe, I ordered one from him, and have not had any scsi
struggles since. <knock on wood>.
The Sony, sounds like a good deal to me, being exteranl adds about a 100
bucks to the cost. For a little over $125, I bought a pcmini tower case,
cables, and active terminator, and currently have four drives in it and room
for three more, with out stressing my ancient 2000s power supply!
Cruising on Autopilot
from beautiful Coastal South Carolina
Thanks Erik.
On the basis of all this HELP input, think I will go ahead and order the SONY
external drive… plus the Fred Fish disk to see if it all works. Will try and
pickup one of those magic terminators everyone mentions.
Do you know any company who carry the Fish CD ?
As my efforts progress, there is little doubt that you will read a new set of
profane cuss words to add to your dictionary. One or two of them have proven
very effective on the Amiga in the past.
All the best, HILARY.
For Fred Fish discs (& the really cool Light-ROM discs by Michael
Meshew!), contact Amiga Library Services directly at:
602-917-0917, or email info@amigalib.com
You can also find them from many mail order houses.
Have Fun! (That SONY is _only_ double speed?!?)
Erik Flom
Thanks for the info' Erik.
Who the heck is Micharel Mischew? Is he related to Michael Jackson? If indeed
he is what they call a music maker, I am far away out of my depth. I commune
with J.S. Bach when he does his gig on the organ. Sometimes I go as far as
listening to Sondheim.
Yes. The drive is a 2 X. speedy thing. I have a 4 X on my proper computer –
the PC. <g>. I don't want to upset my Smithsonian Amiga by feeding it stuff
too fast. It may give me the nasty red writing!
All the best, HILARY.
Michael Meshew is the guy who compiles the Light-ROM CD's for ALS. (Last
time I chatted with him, he was grousing about the fact that ALS was
getting the credit for all his work…..Just giving credit where credit
was due.)
And, no…Michael is no relation to the gloved one. (AFAIK. }:^)
As for the CD:
GET A 4X CD!!!
You'll be able to use it on other PCs in the future, it'll work fine on
your 4000 (just faster!), and it's only $20 more?!?
(BTW, more people use Toshiba than SONY on the Amiga. Make sure your
driver software supports the drive directly. If you're taking my copy, let
me dig it out and make sure it supports your drive…Which model # is it?)
Talk to ya' later,
Erik Flom
Don't know the Model number of the SONY externam SCSI II. CD-ROM player. Am
not too worried about speed – as I put up with the first SONY CD-ROM player
they ever made. It was not a "speedy". I think abouit 0.055 X speed.
Hey… about the "terminator Thingeee". Note in a catalog from JDR
Microdevices – where I get most of my PC stuff, they have TWO different
external SCSI terminator thingeees. One is just an SCSI terminator… it
costs $9.95. The other is an SCSI II. terminator… and it costs $29.95. It
must have gold plated "everything"…
I am getting "in" deeper anbd deeper I fear!
All the best, HILARY.
I think the key thing to look for in an active terminator is the word
'active'. I think they'll run you about $50 minimum. (Another reason I
haven't bought one!)
A SCSI-II terminator probably just uses the new miniature DB-50 connector
found on SCSI-II controllers & boxes these days. (It looks like a standard
50-pin centronics connector shrunk down to the size of a DB-25 connector.)
(10:1 it wouldn't work on the SONY, since most external SCSI boxes
[&CD-ROMs] use the larger dual 50 pin Centonics style connectors for I/O.)
Have fun! (And buy the 4x speed CD! Trust me! }:^)
(Otherwise, you can get an external 2x CD from any mail order house for
$199!!)
Erik Flom
Hi Hilary –
We carry the CD's also, including Fred Fish. Can we help?
Hank
Videology, Inc Where you always get P.O.M.P. and
Service under all circumstances
Hank;
Need some info on Fish CD's. I have the 1-1000 on a CD. What is the latest one
(up to what "Fish" number), how much ($), and can I purchase it from you?
Hank
Hi Hank –
Since the selling price is $19.95 for Gold Fish Disk number 2 (it consists of
anims, surfaces, etc), you can get it direct cheaper from Amiga Library
Services at (602) 491-0048. Ask for Norm.
Enjoy
Hank
Videology, Inc Where you always get P.O.M.P. and
Service under all circumstances
Thanks, Hank.
Does Gold Fish Dsk 2 start at #1000?
Hank
According to Amiga Library Services, the Gold Fish Disk #2 shouldn't be
considered in as the second in the series, since it is made up of animations,
surfaces, etc. not general Amiga utilities. Doesn't begin with any specific
Fred Fish Disk therefore.
Hank
Videology, Inc Where you always get P.O.M.P. and
Service under all circumstances
Hilary,
SCSI termination ALWAYS is supposed to go on both ends of the SCSI bus.
So in your example…it'd go on Dev 3.
SCSI ID's can be in any order on the bus, but termination goes to the
end.
Don
Yes Don, I have always followed the plan you outlined. Terminate the LAST SCSI
device on the chain of devices. Otherwise, remove all device terminations,
except for the last.
What befuddles me is this "special termination". Why is it an advantage over
the method I have used so far? Is there some "extra magic" it performs ?
All the best, HILARY
Hilary,
yes…active termination senses the actual termination values that are
needed and adjusts itself for that.
Don
Thanks Don.
Then… what one does is to remove all terminations from all the SCSI device
string, and stick in this magic terminator at the end.. right?
All the best, HILARY.
Hilary,
Yes…it goes on the bus…at the end, not on a device on the bus.
Don
Thank you Don for info. Will now order the CD-ROM player, a Fred Fish disk,
and that "Wonder Thingeee" we have discussed.
Stand by for many curses in foreign languages, plus a few timid questions.
All the best, HILARY.
No, you always want to have terminators on each _end_ of the bus.
Always two terminators…..no more, no less.
(Well, 99.99% of the time….)
An active terminator replaces _one_ of the two terminators.
In the case you sight, it should be:
COMPUTER (terminated) ->Dev1->Dev2->Dev3 (terminated)
In the case of a board with both an internal connector and an external
connector, it should be:
Dev1 (terminated) ->COMPUTER (not terminated)->Dev2->Dev3 (terminated)
BTW, AFAIK, the best way to 'visualize' a terminator is to consider what
it's purpose is: to dampen signal reflections in a line.
I'm not really an 'analog' guy, but I've been told that the main reason to
have a terminator is to eliminate signal reflections in an electrical
line.
Consider the attenuation you can see on an NTSC signal – where square
waves turn into rounded hills, and improper termination can lead to
ghosting. Supposedly, when dealing with high-speed digital signals like a
SCSI bus, the same problems can crop up. Everytime there is a junction
(connector), a small difference in impedance can result in a reflected
signal. Because SCSI data uses high frequency digital pulses on each data
line, they tend to act like complex RC circuits, where the actual SCSI
cable takes on capacitor-like properties. All the high speed digital data
ends up turning into mush by the time it reaches certain devices.
An active terminator acts to dynamically minimize the high-speed
transients on each line, resulting in a reduction of noise, and squarer
pulses. (Don't ask me how….)
PPS: double speeds are 'antiquated'. For $20 more than the SONY you found,
you could get a quad-speed. (Less for internal 4x speed drives…)
The saga continues….
Erik Flom
Erik;
< In the case you sight, it should be:
< COMPUTER (terminated) ->Dev1->Dev2->Dev3 (terminated)
That doesn't seem to fit with the usual "intelligence", i.e. termination only
for the last device of any chain, does it?
Your explanation of termination was great-thanks- I've saved it in my "pearls
of wisdom" file.
Hank
<< COMPUTER (terminated)->Dev1->Dev2->Dev3 (terminated)
< That doesn't seem to fit with the usual "intelligence", i.e.
< termination only for the last device of any chain, does it?
Ahhh, yes! That _is_ correct, assuming you don't consider the SCSI
Controller as a _device_ of its own!!
If the SCSI controller card is on one end of the chain, _IT_ must be
terminated, just like any other device.
The primary reason for termination is to dampen the signal reflection that
occurs on each end of the bus – so properly designed SCSI controllers will
work best when both ends of the _physical_ bus are terminated.
Thanks!
Erik Flom
>> If the SCSI controller card is on one end of the chain, _IT_ must be
>> terminated, just like any other device.
Erik,
PMFJI, but, as a SCSI controller card, is the A2091 terminated by factory
settings, and how can I set/unset termination, e.g if I use external devices
only ?
The docs that came with the A2091 don't tell you anything about this …
– wkc – … via AP from Hamburg, Germany
I used to have an A2091, but can't remember exactly…..
You should see three terminator packs on the board, near the internal 50
pin connector. If not, then maybe they used the onboard drive's
termination?
I'm not sure whether you should pull them or not – depends on the
configuration. I don't remember doing that to mine, but it was a few years
back.
If it ain't broke, don't fix it. :^)
Erik Flom
>> If it ain't broke, don't fix it
Erik,
everything is working ok with the A2091. With internal HD only, with external
streamer tape only, with both internal HD and external streamer.
And there is no difference if the internal HD and/or the external streamer are
terminated or not, other than a very lite dimmering of the computer's hard disk
control led.
I even can power on/off the external tape streamer without rebooting the Amiga
:-). Try that with any GVP SCSI host adaptor ;-( …
– wkc – … via AP from Hamburg, Germany
Yeah, I've long been a fan of Commodore controllers!
The SCSI on my A3000 was among the fastest when it came out, and all the
A2091's I've worked with have been slow, but stable, performers.
My previous posting about termination was the basic 'rule' of SCSI. I've
made the mistake several times of running my machines without the correct
termination – fortunately, they've always been C= or a WarpEngine, and
they're both rock-steady SCSI controllers.
As you said: 'Try that with any GVP SCSI host adaptor ;-('
I refuse to work on client's machines if they've got a GVP SCSI problem.
I've lost too much hair, and sleep at nights, trying to get their
bass-ackwards termination 'rules' (hah!) figured out!
Later….
Erik Flom
I guess that makes sense. Thanks, Erik.
Hank
Hi Hilary –
Don't know if you got YACDP yet but the doc's, as .guide files, are LHA'd and
in your CMail.
Hank
Videology, Inc Where you always get P.O.M.P. and
Service under all circumstances