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Jeroen Wartenbergh

Lost in getting IIfx external SCSI devices to work - any advice?

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Hi fellow Apple users!

 

I recently acquired a Macintosh IIfx for a project to acces and retrieve 1988-1994 data from ad agencies.

 

Anyway, the IIfx came without it's mandatory SCSI filter (internal) and 'black' terminator. I need to hook up 2 magnetic optical drives, a DDS tape unit, hard disk and SyQuest drive. So far, the IIfx gives nothing but read/write errors. That is, oddly enough. apart from a 1994 Apple certified 500 Mb internal HD (thus, without the filter)...

 

Is there anyone who might have a spare filter and terminator for sale or useful advice on this matter?

 

Kind regards in advance,

 

Jeroen Wartenbergh

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Dunno about the internal filter, not sure mine ever had one? Spec for black terminator resistance is out there. Building your own shouldn't be difficult, especially if any one of your older SCSI devices has provision for SIP resistor packs. That should be as simple as soldering some olde schoole color coded resistor leads together and poking them in the convenient holes. If not, there are a lot of other approached to rolling your own, if none are readily available.

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Nice thread archaeology!

 

CelGen is the only member I can think of offhand who's consistently maintained that the Black Terminator is unnecessary. I've never heard of any "myth" about it being busted. He states that he's never needed one, but that doesn't necessarily equate with it not being needed on the SCSI chain of an early production IIfx. I'd say in most cases it's unnecessary, except when it is, go figure. What's the production date of your IIfx?

 

The active termination suggestion is one I almost made, but the active application of termination whenever needed isn't necessarily the same as providing enough termination for an early IIfx.

 

Forgot about the capacitors, but you've now got the recipe! [:)]

 

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Hi Nglevin & Trash 80,

 

That's a swift reaction! Apology for my lack of technical knowledge:

 

Trash 80: Building your own shouldn't be difficult, especially if any one of your older SCSI devices has provision for SIP resistor packs. That should be as simple as soldering some olde schoole color coded resistor leads together and poking them in the convenient holes.

 

Of the NuBus cards that came with the IIfx, one is a FWB JackHammer, which has 3 (empty) sockets for terminators. Are those intended for SIP resistor packs? Another NuBus SCSI card from 1994 MicroNet Raven Pro hasn't got any of those.  Either way Trash 80, I've never soldered in my life but with the right info I might ask a local person to sort me out and craft what you suggested...

 

Nglevin: The last time the legendary black terminator came up, it was thought to be unnecessary.

 

I'm a little confused but from what I understand, this might work perfectly for adding just a single attached e.g. hard disk. If that's the case, worst case scenario I'll juggle around, attaching one device at a time. However, at this stage, my ioMega ZIP-drive gives errors and both the JAZ and 5 1/4" MO drive aren't even recognized (by FWB HD Toolkit 1.6.2, 1.8 and CharisMac).

 

Trash 80: The active termination suggestion is one I almost made, but the active application of termination whenever needed isn't necessarily the same as providing enough termination for an early IIfx.

 

Speaking regarding it's production date: a barcode sticker, located mid-front on the logic board reads *CK1070G102MA*. A second clue might be a hand-written sticker that doesn't make sense to me (see photo). About the barcode, if I am correct, CK stands for Cork, '1' for 1991 and '07' for week No. 7, right? If that's true, it seems I have actually a very, very first model. Wiki mentions 19 March 1990 as introduction week, so that's week 12. On the other hand, chips very often are marked with a four digit 'yymm' code. Some of the custom chips are marked 9039 and 9028. At this stage I didn't fancy tearing down the Mac down to check for the same date codes located on controller chips near the internal SCSI port, hidden away underneath the drive holding plateau, hoping this info will be sufficient.

 

And by the way, a logic board bar code starting with 107, assuming I'm right it stands for week 7 of 1990, doesn't make sense with chips with production dates from around week 28 and 39...

 

What I've tried so far:

  • See if the Radius Rocket 33 conflicts. I found out it doesn't like the TrueVision TARGA 2000, the DigiDesign AudioMedia I and the MicroNet Raven Pro cards. So for now, I'll focus on testing and getting this work in pure 68030 mode. RasterOps Paintboard Li and Paintboard Turbo and the SuperMac Thunder 24 as well as Thunder II work fine. Same for the Digidesign SampleCell II and Radius VideoVision Studio, a Hurdler II and an unknown 10/100 brandless ethernet card.
  • By switching off the terminator switches on CD burner and MO drives, testing both passive and active terminators on the end of the SCSI chain, hooking up a single device at a time.
  • For the sake of simplicity I used only the bare minimum at the moment: just the SuperMac Thunder, minimizing possible conflicts (I was surprised by the way that this Mac came with so many cards in the first place).

What to do?

  • Give Trash 80's suggestion a chance and look for wiring instructions for someone to work with. T80, do you have info on hand?
  • Search again for a ready to buy, proven terminator solution.
  • Explore an alternative route: buy a USB or FireWire to SCSI adaptor for my Mac Pro and transfer through ftp (utilizing my NAS drive). Might be tricky if not impossible to mount opticals on OS X media with 68k written drivers. Besides, I'm stick with a 1996 NuBus ethernet card that is not mentioning any brand at all...

Right now I feel a little stuck, spending € 300 on a computer with cards that seems to be an isolated island... What to do? I'm sure the IIfx is in good nick, not a single error from the internal SCSI 500 Mb Apple HD (which I kept luckily spare).

 

Thanks for your input so far. To be continued!

 

Jeroen

 

 

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Hi Jeroen,

 

I have a spare black terminator that you may borrow. No idea if it works. Neither of my two black terminators seems to make a difference on my IIfx (although the internal SCSI has just died so it may not have been the black terminator...).

 

Send me a PM if you want to borrow it. It will only cost the price of postage from CH.

aa

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Hi Armour Alley,

 

Wow, that would be awesome!!! Sorry to hear that the internal SCSI died on your IIfx... Hope you can still use your machine by using a NuBus SCSI-card... Do you have one?

 

I suppose that sending it in an envelop (weight is very low) by air will work? Let me know what shipping costs will be and I could pay you by PalPal if that works for you. Can I send my address to you by email? 

 

Although I am very happy to borrow the terminator, it does't mean I stop diving into finding a solution. Because I need to send back the terminator eventually. But right now I'm very happy to be able to connect my equipment.

 

Many thanks in advance,

 

Jeroen

 

ps: I'm native Dutch and don't know what PM means apart from Post Meridiem...

Edited by Jeroen Wartenbergh
What does PM mean?

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Private Messaging within the forum here. Hover the cursor over a member's avatar and click the envelope icon in the popup box.

 

Haven't really played with my JackHammer yet so I don't know with certainty, but if the termination packs are missing on the card it's probably set up for driving devices internally as well as externally? I wouldn't mess with IIfx SCSI Voodoo at all before testing your peripherals running off the JackHammer. Adapters are readily available the external fast/wide connector, but backplane plates for converting the fast/narrow internal bus of your JackHammer to an external connector used to be dirt cheap, but couldn't find one handy on eBay.

 

They look like this:

s-l400.jpg

But they're IDC50 to DB-25 on the external side, maybe cablesonline.com or someone still sells them.

 

Found this pair of cables available now for $20. You can just hang the Centronics end out a NuBus backplane opening. I'd cut some of the five internal connectors off to keep the length short. IDC Centronics-50 straight to card or internal is better anyway.

 

s-l1600.jpg

 

PM me for the link if interested. I may snag them for myself if not.

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Hi Jeroen,

 

 The black terminator is packed and will be posted tomorrow sometime. It will set you back the princely sum of CHF 3.70.

 Sorry about the using the initials for private messaging. I've gotten very used to it and it didn't occur to me that it mightn't be in universally understood.


A few things to bear in mind: you should get yourself a PDF copy of the FWB Jackhammer manual – http://archive.retro.co.za/mirrors/68000/www.vintagemacworld.com/pdfmanuals/jackhammersc.pdf.

Make yourself a boot floppy with System 7.1 and put the following extensions on it:

 0. You can take almost all of the extensions and control panels out. I'd leave in General Controls, mouse, keyboard, startup disk;

 1. SCSI Probe 4.2 – This will tell you if the SCSI chain is terminated – http://macintoshgarden.org/apps/scsiprobe;

 2. CD-Sunrise – This will mount many drives as read-only volumes – http://www.vintageapple.org/macdrivers/disk.shtml;

 3. If you have space, MO Formatter from Fujitsu – https://www.driverguide.com/driver/detail.php?driverid=256249

Take out all of the cards except one of the graphics card, say, the SuperMac Thunder/24, and unplug the SCSI harddrive.

Start with as few items as possible and then add on one item at a time.

 

I assume, of course, that your floppy drive & floppies work.

Can you boot successfully from the floppy? If not, you may have a hardware problem. Leave it over night and see if there is any change the next day.

If it boots, super. Shut down. Unplug the power supply. Touch the power supply to discharge any static electricity that you may have.

Plug in, say, the hard-drive and reboot from the floppy. If you can boot successfully, check SCSI Probe. Is the drive there? Does it need mounting?

If not, shut down as before and follow the same procedure. Unplug the SCSI drive. Restart from the floppy again. If all is well, shut down, follow the procedure and plug in one of the external SCSI drives, say the Iomega Zip-drive. Set the termination power at the back to on. Boot from the floppy again.

If it boots successfully, check SCSI Probe. Is the Zip drive registered under SCSI ID 5 or 6? Press the green bar at the top of SCSI Probe 4.3. If the SCSI bus is not terminated, it will say so there.

And so on. Reduce the number of variables you have. Once you have known working drives, you can then start adding to them.

If you think that the black terminator might be the solution to a problem, connect another SCSI drive with a different SCSI ID to the Zip drive and remember to set the termination on the Zip drive to off. Plug the black terminator at the end of the SCSI chain and reboot from the floppy.

 

My apologies if this is very basic. It's how I troubleshoot complex systems. Start simple and work up.

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Hi Armor Alley,

 

Thanks for this extensive e-mail. It could't be more clear! Tomorrow I'll transfer € 3,70 to you (little more than 3,70 CHF).

 

Also of great help: the link to the JackHammer manual and software. Although I have some software myself, I won't bother using it as you have a IIfx as well and it worked for you so I'll go with the links you've provided, thanks! And by the way, I totally agree with your basic approach. It makes thing easier to oversee and from there, I'll add functionality. So no sorry mate, it's good thinking!

 

I have plenty of SCSI cables, actually way too much. However I think it is best to use relatively short ones from Rorke Data, Inc. and AMP, they used to make proper shielded cables... I always mistrusted those cheap, thin cables...

 

In case of bootable floppies, I have System 7.1.0, fine for now. I'm looking forward to experiment this weekend in trying to make this IIfx into a working machine!

 

Some background info: I work as a graphic designer and I've been ask to restore archives from a charity organization called 'Artsen zonder grenzen', 'Doctors with no boundaries', design a book describing their work. Source media are DDS tapes (worried about missing RetroSpect index files), 3,5" and 5'1/4" MO drives, JAZ and even old SyQuest cartridges, known for being unreliable. Their internal studio tried all sort of stuff, from buying SCSI adapters for their iMacs to Sheepshaver. Well, good luck with that, old 68k drivers and data and resource forks...

 

So, I offered to sort them out on a non-paid, volunteer basis. Any way, looking forward to put the fx into action! Some of my work (English text) is on: www.wartenbergh.studio

 

Finally, just one remark on your helpful thoughts:

  • If you think that the black terminator might be the solution to a problem, connect another SCSI drive with a different SCSI ID to the Zip drive an d remember to set the termination on the Zip drive to off. Plug the black terminator at the end of the SCSI chain and reboot from the floppy.
    My ZIP has actually 2 DB-25 connectors. Assuming the black terminator has a Centronics 50 connector, I'll use my Sony 5.2 Gb optical drive instead. If that works, I'll add the ZIP between the IIfx and Sony since the Centronics terminator needs the be at the end of the chain. BTW, same goes for my JAZ drive.

Thank you soon much!!!

 

All the best,

 

Jeroen

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2 hours ago, Jeroen Wartenbergh said:

Some background info: I work as a graphic designer and I've been ask to restore archives from a charity organization called 'Artsen zonder grenzen', 'Doctors with no boundaries', design a book describing their work. Source media are DDS tapes (worried about missing RetroSpect index files), 3,5" and 5'1/4" MO drives, JAZ and even old SyQuest cartridges, known for being unreliable. Their internal studio tried all sort of stuff, from buying SCSI adapters for their iMacs to Sheepshaver. Well, good luck with that, old 68k drivers and data and resource forks...

 

If your main goal is to get files off these old media sources, there may be an easier way to go about it.

If you connect one of these drives to a SCSI card on a modern system you can use DD to image the media then mount the image file under Basilisk II

Creating an image: http://www.savagetaylor.com/2018/05/28/setting-up-your-vintage-classic-68k-macintosh-creating-your-own-boot-able-disk-image/

Getting a SCSI card working under Windows 10 (sorry don't know how for OS X) http://www.savagetaylor.com/2018/02/11/scsi-on-windows-10-adaptec-aha-2940-adaptec-29xx-ultra-or-aic-7870-adaptec-78xx/#comment-2191

 

I've connected my SCSI zip drive and SCSI jaz drive this way, and copied disks to image files to mount on my Windows 10 system under Basilisk II.   If the disk has multiple partitions you can try SoftMac or MAME.  Both of these support reading full disk images and will recognize partitions.  Basilisk II will only read the first partition.

 

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Borrowed from Sean, fellow 68k member: His Apple 'black' terminator, model 590-705-A !!! Awesome, and I think it solved problems to a certain extent. Although the terminator is black and from Apple, I was a little surprised: it's some sort of pass-through terminator...

 

Earlier in this thread, 4 Apple Terminator are mentioned:

  • 590-0304 (original terminator)
  • 590-0695-A (replaces 590-0304, new PLATINUM terminator)
  • 590-0695-B
  • 590-0705

Although the 590-0705-A isn't mentioned specifically, where the 590-0705 is, I wonder if that A would stand for a pass-through type of connector. I suppose it does, remembering the warning 'never include 2 black terminators' on other articles/threads. Makes sense, as with a 'common' terminator, you can't add more than one anyway.

 

Finally, my IIfx is able to at least recognize my Sony SMO-F551 optical drive, last in the SCSI chain (ID6) and the ioMega ZIP drive (ID6), between IIfx and MO. ZIP functions normally, the MO drive doesn't. Upon inserting a disk, the front led light changes from constant orange to a blinking green light. Oddly, Same happens with the IIfx switched off, so perhaps my drive broke down as I havent used it for 10 years or so.

 

So far so good. Last week I ordered an old stock, new CD-R drive from OWC. When it arrives next week, I'll do some more testing. Trash 80 (thanks!) showed a link of a cable having a standard internal SCSI connector at one side and a Centronics 50 connector at the other side. I'm planning to use that on the FWB JackHammer internal 8-bit connector by allowing the cable to connect outside the fx with external gear, ignoring the SCSI bus of the IIfx altogether. 

 

The weird thing is that my internal drive is connected without a mandatory SCSI filter and still does the job without any trouble. Still I wonder if other, external devices, would behave different, better, with such a filter.

 

To be continued, thanks everybody for your help and thoughts!

Edited by Jeroen Wartenbergh
Re-wrote intro.

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On 10/16/2018 at 1:58 AM, Realitystorm said:

Not sure if you found this https://support.apple.com/kb/TA42169?viewlocale=en_US&locale=en_US, Macintosh IIfx: Termination (4/95)

The contents of this link, in case it becomes no longer available are here:

Macintosh IIfx: Termination (4/95)


This article contains information about Macintosh IIfx termination and external terminators.
 
 
This article has been archived and is no longer updated by Apple.
There have been 4 different external terminators distributed by Apple. Two are identical except for the part number.

Part Number Description
----------- -----------
590-0304 The original terminator.

590-0695-A Replaces 590-0304. This is the new PLATINUM terminator

590-0695-B
& 590-0705 These are BLACK and are identical, except for the part
. number. Apple built approximately 10,000 having the part
. number 590-0695-B; later manufactured black terminators
. are numbered 590-0705. One black terminator ships with
. every revenue Macintosh IIfx, but can be ordered
. separately from Service using part number 590-0705.

. Note:
. Only 1 black terminator is ever needed at a time; more
. details are below. These black terminators are
. officially called the Apple SCSI Cable Terminator II.


The Other Two Macintosh IIfx SCSI Bus Components
================================================

Internal SCSI Termination Block
-------------------------------
The Internal SCSI Termination Block provides internal termination resistance for Macintosh IIfx systems WITHOUT INTERNAL HARD DRIVES. All Macintosh IIfx computers that shipped without internal hard drives had the Internal SCSI Termination Block installed. This component plugs into the Internal SCSI Filter and it looks like a "T", with a 50-pin female connector on the bottom.

Internal SCSI Filter
--------------------
The Internal SCSI Filter provides termination capacitance for internal Macintosh IIfx hard drives that shipped prior to March 19, 1990 or any third-party hard drives. After that date, Apple hard disk drives shipping in the Macintosh IIfx contained the proper termination capacitance. The filter has a 50-pin female connector on one end and a 50-pin male connector on the other. When connected to an internal drive the drive cable should be connected directly into the logic board and plug the Internal SCSI Filter block between the drive cable and the 50-pin connector on the hard drive. When there is no hard drive the SCSI Filter is connected to the logic board, and the Internal SCSI Termination Block is connected to the filter.

All Macintosh IIfx computers that shipped without internal hard drives had the Internal SCSI Filter and the Internal SCSI Termination Block installed. When you add a third-party drive remove the Internal SCSI Termination Block, but leave the Internal SCSI Filter connected to the logic board. Termination needs to be provided by the resistors on the internal third-party drive.


Determining What Terminators to Use and When
============================================

No External SCSI devices Connected
----------------------------------
Termination is provided by either the internal hard disk, or by the Internal SCSI Termination Block.

With a Third-party Internal Drive
---------------------------------
The third-party drive should be internally terminated. Plug the drive cable directly into the logic board and plug the Internal SCSI Filter block between the drive cable and the 50-pin connector on the hard drive (Cable and filter order is important for this to terminate correctly). The Internal SCSI Termination Block needs to be removed (it looks like a "T"). Plug the drive cable directly into the logic board and plug the Internal SCSI Filter block between the drive cable and the 50-pin connector on the hard drive.

With Any External SCSI Devices Connected
----------------------------------------
Use only ONE black terminator at the end of the SCSI chain. Make sure that all built-in terminators are removed from external third-party SCSI devices (Apple's external SCSI devices do not contain internal terminators).

NOTE:
A flyer in the Macintosh IIfx Finished Goods box instructs customers to
return self-terminating SCSI devices to the Service Provider to disable the termination. Removing the termination can be performed by the user in some circumstances--a user should refer to the owners manual or check with the manufacturer if they are uncertain.

WARNING:
-------
Under no circumstances should you use more than one black Apple SCSI Cable Terminator II on any external SCSI chain. This may damage the logic board or whatever device is providing termination power.

With An Internal Disk Drive And External SCSI Device
----------------------------------------------------
Both the internal SCSI drive and the last SCSI device in the external SCSI chain need termination, and you need to plug the Internal SCSI Filter block between the drive cable and the 50-pin connector on the hard drive.


Why Is There A New Black Terminator For The Macintosh IIfx?
===========================================================

One of the features of the Macintosh IIfx is a new SCSI chip that provides SCSI data transfer rates up to 3MB per second, faster than any earlier Macintosh systems. To achieve these transfer rates, components on the Macintosh IIfx logic board are smaller and faster, this makes them more susceptible to signal reflections on the cable. The new terminator adds the filter capacitors and changes the resistor values for some of the signals to reduce the reflections.


How Can Third-party Drives Take Advantage Of The Higher Scsi Throughput?
========================================================================

Any SCSI hard drive that can sustain transfer rates above 1.25MBps will operate faster on a Macintosh IIfx. No Apple hard drive, including the HD160 SC, takes advantage of this higher transfer rate.


What To Do With Less Common System Configurations
=================================================

In some remote cases someone might remove the internal drive from a Macintosh IIfx they will not have the correct internal termination. In this situation, you should order and install a Internal SCSI Termination Block (Apple Service Part #590-4515) and Internal SCSI Filter (Apple Service Part #590-4516), and use the black terminator if you have any external drives; however, if you don't have access to an internal termination block, you can connect use the new platinum terminator (590-0695-A on the terminator) to the beginning of the SCSI chain and, as always, connect the black terminator at the end of the chain. Again, what is preferred is to order the Internal SCSI Filter from service.


Article Change History:
13 Apr 1995 - Added information on having internal and external drives.

Support Information Services
Published Date: Feb 18, 2012
 
 
There is also another article lifted straight from www.fenestrated.net from Apple below:
 
ADC Membership Technical Business Join ADC
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NOTE: This Technical Note has been retired. Please see the Technical Notes page for current documentation.

Technical Note DV15
SCSI Termination
 
tnmenutop.gif
CONTENTS
 

Why Is the Terminator After Sarah Connor?

How to Stop the Terminator

External Termination

You're Terminated

Macintosh Quadra Termination

PowerBook Termination

PowerBook Duo Termination

Termination Outlined for Each Macintosh

References

Change History

Downloadables

tnmenubottom.gif

This Technical Note discusses SCSI termination on the Macintosh, including the new rules of termination that are necessary with the advent of the high-speed Macintosh IIfx.

Updated: [May 01 1992]

 


Why Is the Terminator After Sarah Connor?

One of the features of the now obsolete Macintosh IIfx was a new SCSI chip that provides SCSI data transfer rates up to 3 megabytes per second, faster than any Macintosh model prior to the Macintosh Quadra. To achieve these transfer rates, components on the Macintosh IIfx logic board were smaller and faster, requiring different termination configurations from those of previous Macintosh models.

The Macintosh IIfx requires the use of a combination of the following three new termination parts. Users need to use these parts instead of existing SCSI termination parts to configure a Macintosh IIfx with SCSI devices. The Macintosh Quadra does not require special termination as the Macintosh IIfx does, but it does have some special rules of its own and these are discussed in a later section.

Apple SCSI Cable Terminator II: The Apple SCSI Cable Terminator II is a revised external terminator for the Macintosh IIfx. All finished goods Macintosh IIfx systems ship with this terminator in the box. It is easily recognized because of the black color. Under no circumstances should one use more than a single Apple SCSI Cable Terminator II on an external SCSI chain--doing so may damage the logic board.

Internal SCSI Termination Block: The Internal SCSI Termination Block provides internal termination resistance for Macintosh IIfx systems without internal hard drives. All finished goods systems shipping without internal hard drives have the Internal SCSI Termination Block installed.

Internal SCSI Filter: The Internal SCSI Filter provides termination capacitance for internal Macintosh IIfx hard drives that shipped prior to March 19, 1990. All finished goods systems shipping without internal hard drives have the Internal SCSI Filter installed.

The new termination configurations are simple, and you can remember them with a single rule: Macintosh IIfx systems with external SCSI chains require a terminator at both ends of the SCSI chain. One is internal to the system, while the second is external, located at the end of the chain.

The reason for the new terminator is that on the Macintosh IIfx and future hardware, the SCSI controller chip is a 2 micron part, which makes it very fast. One of the results of this speed is that the chip now thinks that glitches in the /REQ line are real signals. This problem is not likely to occur on all of the Macintosh IIfx machines, but if you have a problem with your hard drive not getting mounted on the new machine, you should try a new terminator first. The symptom is more likely to show up on machines with several (three or more) external SCSI devices attached to the computer and long strands of SCSI cables. Figure 1 illustrates the old-style terminator with the signal showing the spike propagation.

Old-Style Terminator (Gray)

Figure 1 - Old-Style Terminator (Gray)

Basically, if a majority of the data lines change state at once, there is a sudden drain on the TPWR line, which is resistively coupled to all of the lines, including the /REQ line. This sudden drain causes a spike in the line, and this spike is propagated into the /REQ line and to the SCSI controller chip. The newer SCSI controller chip in the Macintosh IIfx interprets this spike as a /REQ signal and starts reading data from the data lines; however, since the data lines need 55 ns to settle, the data that the controller chip reads is junk.

All internal hard disk drives sold by Apple with the Macintosh IIfx and later machines have the Internal SCSI Filter installed; however, most third-party drives do not yet have this filter installed and must be modified by a qualified service provider to work correctly with the Macintosh IIfx.

Back to top

How to Stop the Terminator

Since the problem is caused by a drop in the TPWR line, the fix is to smooth out the line. One need only add a 2.2 uF capacitor and a 0.01 uF ceramic capacitor as illustrated in Figure 2. These capacitors act like a battery and provide a little extra current when it is needed. This extra current results in a smoother signal, which the SCSI controller chip does not interpret as a /REQ signal.

New-Style Terminator (Black)

Figure 2 - New-Style Terminator (Black)

This new type of filter is only for internal hard disk drives. The Macintosh IIfx ships with a new and improved external terminator (black in color), so hard drive manufacturers do not need to worry about external termination. Apple also ships an internal filter with every Macintosh IIfx that handles the capacitance problem. This internal terminator has two parts. The first is the resistors for the terminator. This part should already be installed on all internal hard disk drives, so it is used only for CPUs that do not have an internal hard drive. The second part of the internal terminator is the capacitor filter. This filter should be installed on the hard disk drive end of the SCSI internal cable. If your hard drive implements the new capacitors, you can, and should, install the capacitor filter--you cannot have too much capacitance.

Back to top

External Termination

If you manufacture an external SCSI device, do not include termination in it. The only terminator that should be outside a Macintosh IIfx is Apple's external terminator, and it should be at the end of the SCSI chain. If you make a SCSI terminator, it is most likely incompatible and may cause damage to the hardware or the data. If your SCSI device cannot connect with Apple's terminator, then you should provide an adapter that allows your SCSI device to attach to the provided terminator.

Note: A notice in the Macintosh IIfx finished goods box instructs customers to return self-terminating SCSI devices to the service provider to disable termination.

Back to top

You're Terminated

Not every Macintosh IIfx owner is likely to experience this inconvenience, but a few will. If your customers report problems that appear to be termination related, then the first possible solution is to fix the terminator (for external devices) or implement the filter (for internal devices). If you manufacture an external SCSI device that is self-terminating, you should remove it. This incompatibility will continue with future hardware products and could even surface on the Macintosh IIci.

Back to top

Macintosh Quadra Termination

Proper SCSI termination is critical for correct operation of the Macintosh Quadra computers, just as with all Macintosh computers. The Macintosh Quadra computers require external SCSI termination at the end of the device chain, either supplied by the last device in the chain, or using a standard Apple SCSI Cable Terminator (M0332LL/A). Note that this is the standard SCSI terminator, notthe black terminator required by the Macintosh IIfx (although the black IIfx terminator may be used as well).

Termination is generally supplied at the factory for use with internal SCSI devices. Some early floppy-only Macintosh Quadra 700 units may not have internal termination, so users who attach external SCSI devices (without having added an internal SCSI device) may need to double terminate their external SCSI chain. Properly terminated floppy-only Macintosh Quadra 700 units will have a terminator inserted into the motherboard internal SCSI cable connector. Users of internal SCSI devices must, of course, remove this terminator before connecting their internal SCSI device.

The Macintosh Quadra 900 is the first Macintosh computer to provide a separate, internal SCSI bus. This bus is physically isolated from the external SCSI bus and must also be properly terminated. The cable provided with the machine includes all the termination necessary, so allinternal devices must have SCSI termination removed before connecting to the internal Macintosh Quadra 900 SCSI cable. If extra termination is supplied it may cause intermittent hardware failures as well as physical damage to the device.

Developers who ship terminated SCSI devices for possible internal use in the Macintosh Quadra 900 must provide users with instructions for removing the termination.

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PowerBook Termination

There are two important points that one must be aware of when it comes to termination on the Macintosh PowerBook computers. The first point is that termination on the PowerBook computers is supplied by the internal hard drive. PowerBook computers depend on the internal hard drive to supply termination so that they are properly terminated when placed in SCSI disk mode. In SCSI disk mode, the PowerBook is just another hard drive in the SCSI chain. This is because all other subsystems have been shut down. Because the PowerBook is internally terminated by the hard drive, it must always be at the end of the SCSI chain. If you have two PowerBook computers and other devices on the chain, one PowerBook must be the very last device in the SCSI chain (in SCSI disk mode) and the second PowerBook must be at the beginning of the chain (Initiator). This also means that it is not possible to have more than one PowerBook on a single SCSI bus in SCSI disk mode.

The second point to be aware of is that the PowerBook computers do not supply termination power. They rely on external devices to provide termination power on the bus. If there are other devices on the bus that provide termination power, we recommend that the connection to the first device out of the PowerBook be terminated. It is not required that you do this. This ensures that the cable is as close to ideal as possible.

Because termination power is not supplied by the PowerBook computers, we also advise that you do not have powered off devices on the bus. This is true not only for the PowerBook computers but for all Macintosh products. It has been found that having devices powered off and on the bus causes degradation to performance and signals. A termination problem can cause incorrect data to be passed during a SCSI transfer. Therefore, the rule is this: Do not have powered off devices connected to the bus. Also, do not power on a device connected to the bus after booting, and never connect one while the system is on.

If you still have troubles with the PowerBook after following the termination rules, be sure to check that you have proper cables and that the other devices on the bus also follow termination rules. Some devices are not following the description of how Apple's devices work, and following the guidelines of the Apple cable guide does not apply with non-Apple devices. If you have non-Apple cables, be sure that they meet Apple SCSI specifications. It is possible that other devices on the bus and improper cabling are what is causing trouble for you.

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PowerBook Duo Termination

Unlike the other Macintosh PowerBook computers, the PowerBook Duo models do not rely on an external device to provide termination power. Both the Deskbar and the DuoDock provide termination power to the bus. They are actively terminated, which means that they provide termination power and have the best architecture for termination of any other device on the bus.

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Termination Outlined for Each Macintosh

Below is a table that outlines the termination specifics of all Macintosh models (current as of this writing). It also describes whether termination power (TPWR) is supplied for either the internal or external SCSI bus, depending on which is present (one or both). The column on the far right describes which terminator is required when the CPU (currently PowerBook computers only) are in SCSI disk mode and functioning as an external storage device on the external SCSI chain of a Macintosh. Below the table is an ASCII representation of the active termination concept, which is new as of the Macintosh IIv, Macintosh Centris, and Macintosh Quadra models.

dv_15_table1.gif

dv_15_table2.gif

* "...an active termination circuit automatically terminates the [internal device] when it is the last device on the bus. If a terminated device is attached to the external SCSI port, the internal termination is deactivated."--p. 18 of Macintosh IIvx, IIvi, Performa 600 Developer Note.

dv_15_trans.gif

"The Macintosh Centris 610, Macintosh Centris 650, and Macintosh Quadra 800 computers include a new feature that automatically provides the proper termination when no external device is connected. . . . When one or more devices are connected, the circuitry detects the external termination during system reset and disconnects the termination on the logic board."--p. 19 of Macintosh Centris 610, Macintosh Centris 650, and Macintosh Quadra 800 Computers Developer Note.

Termination on Apple Printers

The Apple LaserWriter IIf and IIg and Apple LaserWriter Pro 630 printers require the same terminator as the IIfx--Apple SCSI Terminator II (M5871G/A)--when connecting up to seven external SCSI storage devices (which are for storing downloadable fonts, not for connecting the printer to a Macintosh).

The LaserWriter Pro 630 is the first Apple LaserWriter that can also take a single internal SCSI hard drive (for font storage) in addition to six (for a total of seven) external hard drives. Any internal drive must not be terminated internally since permanent termination is supplied on the motherboard. This termination cannot be removed. The internal hard drive's SCSI ID is hardwired to the motherboard; it is ID 6. Since this drive also counts as one of the seven total devices allowed on the bus, any external device must not have SCSI ID 6 when the internal drive is present. If no internal hard drive is present, SCSI ID 6 is still reserved--external SCSI devices may not use ID 6 even if no internal hard drive is present. The end of the external SCSI chain must also be terminated, whether an internal drive is present or not.

The LaserWriter Pro 630 does supply termination power (TPWR) to the internal device but not to external devices. The LaserWriter IINTX, IIf, and IIg printers do not supply TPWR.

The Apple LaserWriters IINTX and IINTXJ require the standard, gray Apple terminator (M0332LL/A) when connecting external storage devices.

The Apple Personal LaserWriter SC and IISC printers as well as the Apple Color Printer are SCSI devices themselves; that is, rather than being networkable printers, they connect directly to the SCSI bus of the Macintosh. These printers require the standard, gray Apple terminator, unless you're using them with a Macintosh IIfx, in which case you should use the black terminator. In other words, for the SCSI printers (only), the termination requirements are dictated by the Macintosh since the printer functions as just another SCSI device on the Macintosh computer's SCSI bus.

Below is a chart that will help you determine the termination characteristics of all of Apple's printers. Printers with no SCSI implementation are included just for the sake of completeness, so those characteristics that do not apply will list n/a, for "not applicable," under the appropriate heading(s).

dv_15_table3.gif

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References

Macintosh Technical Note "Fear No SCSI"

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Change History

01-April-1990

Originally written.

01-May-1992

Added a discussion of Macintosh PowerBook and PowerBook Duo termination and termination for Apple printers.

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Downloadables

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Acrobat version of this Note (536K)

Download

 

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Hi ArmorAlley,

 

Thanks for posting the article. I've actually read the article. That way I knew your terminator is probably the 'black terminator', although the 'A' version is not mentioned specifically. At this stage I've tried what I could possibly try. Searching for a SCSI filter that seems to be mandatory yielded no usable results. So still a little stuck and awaiting parts. At least external drives (the Sony MO drive) is recognized and reading and writing to the ioMega ZIP works, so I assume the IIfx's SCSI-bus is not damaged...

 

I've never owned a IIfx but taming it's SCSI bus termination thing feels like a drag...

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I have to read both of these articles very carefully. I've had a U320 drive in my IIfx for last 4-5 years and I never knew about the internal SCSI filter. The massive 500MB HD that came with it didn't have one on it. My internal SCSI doesn't work anymore and I'm not sure if that is related to the IIfx's special relationship with SCSI. I don't have internal Molex power either and that's a nuisance too. I use an external drive connected to a FWB JackHammer. My board was recapped by uniserver 3 years' ago and it certainly worked once I received it from him.

 

I have had mixed results with the black terminator using external SCSI on my IIfx. Sometimes I needed it, sometimes I didn't. I could never really find a pattern. However, I've never really had problems connecting external SCSI devices to the IIfx, as long as there were no conflicting SCSi numbers and only the last device on the chain was terminated.

Edited by ArmorAlley

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Hi ArmourAlley,

 

Food for thought: you never used a SCSI filter on your internal 500 Mb HD... Well, my IIfx came with a massive 40 Mb Apple HD (5 1/4"), and didn't had a SCSI filter either! Either way it crashed after a couple hours of use, made a scraping metal on metal noise, terrible!

 

I had an old 1994 500 Mb Apple certified HD spare, it was just plug and play!!! So for now I'll use it as it is, with a working ZIP-drive. After the weekend I'll receive a brand new old stock CD-RW from Other World Computing and see if I get it to work, as my IIfx is still an island.

 

It came with a 10/100 Mbit ethernet card, but I can't find a driver as I don't know which make and model it is... No luck posting that question with photos here...

 

Again thank you so much for your input and borrowing the terminator.

 

Cheers,

 

Jeroen

 

 

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On 10/21/2018 at 2:51 PM, Jeroen Wartenbergh said:

It came with a 10/100 Mbit ethernet card, but I can't find a driver as I don't know which make and model it is... No luck posting that question with photos here... 

Best bet would be to use software to read out the DeclROM. DeclROM will ID the card.

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Thanks guys!

 

No luck yet in solving my SCSI-issues. Although I can access my Zip-drive, I still have trouble with all other devices. Looking and finding a SCSI-filter seems to be impossible. So right now, it is like an isolated island...

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1 hour ago, Jeroen Wartenbergh said:

Thanks guys!

 

No luck yet in solving my SCSI-issues. Although I can access my Zip-drive, I still have trouble with all other devices. Looking and finding a SCSI-filter seems to be impossible. So right now, it is like an isolated island...

For now my best bet seems to be finding an second USB ZIP-drive in order to transfer software to the IIfx or better: a friendlier machine like a NuBus Quadra or PPC... Enabling me to use external devices...

This also means that the whole reason to acquire the IIfx is senseless, hoping to sign up a freelance job to retrieve old documents for a book publisher. I even doubt whether I will ever fetch € 300 for it as it has only 32 Mb RAM and a mere 500 Mb HD (including the FWB JackHammer, Radius Rocket 33 with just 64 Mb, the SuperMac Thunder II 1152, DigiDesign SampleCell II and an useless SMC 10/100 Mbit ethernet card (no drivers around)). Either way quite a delay will occur... And selling it without the borrowed Terminator II which renders it pretty much useless.

Edited by Jeroen Wartenbergh

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Did I miss something here? The Jackhammer card is SCSI and bootable and does not need a filter to work. Manuals for it can be found with a quick search.

 

All those cards listed are easily sold , same with the IIfx itself.

 

You purchased equipment without having the job???

 

A quick google search said that ethernet card was from Sonic systems, try the files found here:

http://vintageapple.org/macdrivers/network.shtml

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Hi Unkown_K,

 

Sorry for missing you out on data. The FWB JackHammer is a tale on itself as it misses all three SIP-terminators. After some research I believe they need an impedance of 110 Ω. Finding the is a quest on itself. The other SCSI-card that came with the IIfx is an equally useless MicroNet Raven Pro II dual bus fast/wide SCSI. A card that is not compatible with Apple's SCSI manager 4.3 and although also bootable and allowing partitions up to 4 Gb on HFS-partitions, disk maintenance software is doubtful to be reliable as - to my knowledge - little is known about this card, creating a long-term reliability risk. Besides that, I'm missed out on software. A pitty as this card yielded a sustained 16 Mb/s data rate on my AWS 9150/120 (yes, faster NuBus 90 architecture).

 

Indeed I purchased the IIfx without securing the financial gains. Partly due because my first Mac was a same looking IIx. Call it love on first sight...

 

Thanks for the link for the Sonic Systems drivers. I will try to see to find a way to install those drivers...

 

Cheers,

 

Jeroen

 

BTW: great to hear that the IIfx and all cards might fetch around $ 40 each (with US shipping included for NuBus cards, IIfx is way more expensive to ship)... Also included were two unknown cards from RasterOps (Paintboard Turbo), a TrueVision TARGA 2000 Pro, a Radius VideoVision Pro  both with cables and/or breakout box, A Miro Rainbow PSD card for the IIfx, all cards I can't find on eBay to determine market prices. A Dutch user group states that basically all these cards are worth in-between € 2 to € 10. In other words, of no interest to the US market as shipping costs are close to € 25 alone, so why spending $ 2 on those cards - if ever. I'll see and look into available drivers for an Quadra or PPC era Mac...

Edited by Jeroen Wartenbergh

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