The comp.sys.apple2 Usenet newsgroup Apple II FAQs originate from
the Ground Apple II archive, 1997-2004. Administrator: Steve Nelson
Csa2 FAQs-on-Ground ref: Csa2HDNSCSI.txt rev074 May 2004
Hard Disks & SCSI Interfaces
001- How difficult is it to add a hard drive to my IIgs?
002- What kinds of hard drive systems are available?
003- What do SCSI ID numbers mean?
004- What is "SCSI-2" and how is it different from SCSI-1?
005- Will a SCSI-2 hard drive work with an Apple II system?
006- Will my Rev. C SCSI Card work with a SCSI-2 drive?
007- What is SCSI "termination power"?
008- Can I avoid the "RamFAST/SCSI is searching SCSI bus" delay?
009- What is the pin-out for the standard 50-pin SCSI cable?
010- What's the SCSIHD.DRIVER patch to ignore DRIVER43 partitions?
011- What is the "bad bug" in the ROM 3.01e RamFAST?
012- What are correct HS SCSI settings, etc. for a Bernoulli drive?
013- What are the settings for a CMS hard drive controller card?
014- Does it matter when I power-ON my SCSI hard disk?
015- Can I leave SCSI devices I'm not using turned OFF?
016- Is there a generic SCSI tutorial available for downloading?
017- What is the correct time-out setting for a Focus hard drive?
018- How do I modify my Apple HSS card to supply Termination Power?
019- Can I get a Focus drive bigger than a couple hundred MB?
020- My hard disk is on a CMS SCSI. How do I install System 6.0.1?
021- How is DMA set for SCSI cards with 8MB RAM cards on the GS?
022- My 20MB Focus bombs and there's some goo on the card. A fix?
023- Where can I find the RamFAST manual on the net?
024- How can I tell which Apple SCSI card I have?
025- Where can I find Profile maintenance and formatting info?
From: Bradley P. Von Haden
001- How difficult is it to add a hard drive to my IIGS?
Adding a hard drive is not much of a problem. Usually, you will need to insert an interface card, possibly connect a cable or two, and change a Slot setting in the Control Panel Desk Accessory.
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002- What kinds of hard drive systems are available for Apple II users?
The most versatile and most common hard drive set-up is an internal SCSI interface card and an external SCSI drive. Hard drives, cd-rom drives, removable media (SyQuest, Iomega), flopticals, and scanners all can be added to the SCSI chain. Insert the card in a slot, connect a cable or two, and change a slot setting.
The preferred SCSI card is the RamFAST Rev. D SCSI card. The next best card is the Apple Hi-Speed SCSI card.
Here are some RamFAST notes:
- faster than Apple Hi-Speed, especially in ProDOS
- provides termination power to the SCSI chain
- allows partitions to be mapped in ProDOS
- device drivers come on the card in the upgradeable ROM chip
(3.01f)
- allows up to 8 devices to be added to the chain
- allows up to 12 partitions to be active at any one time
(switchable)
- allows up to 12 partitions per drive
- about $130 new
Here are some Apple High Speed notes:
- no longer produced or supported by Apple
- does not provide termination power to the SCSI chain (can be
modified to provide termination power)
- does not allow partitions to be mapped in ProDOS
- device drivers are software
- allows up to 7 devices to be added to the chain
- allows over 100 partitions to be active at any one time
- allows up to 20 (?) partitions per drive
- about $110 new (if still available)
For the hard drive itself, look for a SCSI drive in an external enclosure with the following features:
- 30 day money-back guarantee
- external SCSI ID switching
- dual 50 pin SCSI connectors
- no or switchable termination (use an external terminator at
end of SCSI chain)
- switchable termination power (on/off) is a plus for users of
SCSI interface cards which do not supply termination power
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From: Rubywand
Another way to go is a 2.5" IDE drive mounted on an IDE interface card. This "hard card" plugs into a Slot-- usually Slot 7. Alltech sells the Focus Hard Card in varying sizes (e.g. 60MB for $99) with system software installed. SHH Systeme offers the FileCard (about $170 + cost of drive) as well as a series of IDE controller cards to which you can add a 2.5" IDE drive (about $120-$170 including mounting kit).
The IDE hard card approach offers speed and capacity comparable to SCSI, very easy installation, and, it eliminates hassles with external boxes and cables. Of course, you will still need to add a SCSI interface card if you want to connect a SCSI CD-ROM and/or Zip Drive.
Note: If you want your system to include a SCSI CD-ROM drive, it is best to have a SCSI Zip Drive or SCSI hard disk connected to the SCSI interface, too. This provides a write-able medium for saving SCSI interface card setup parms.
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From: Rubywand
003- What do the SCSI ID numbers mean?
SCSI ID numbers identify devices on the SCSI chain. Each device should have its own, unique ID number in the range 0-7. (If two devices on the SCSI chain have the same ID number, there will be a conflict and your system will not function correctly.) Higher numbered devices have higher priority-- get 'looked for' first-- so, it is standard practice to set the device you boot from to 6 or 7.
Most external SCSI devices have a thumbwheel switch, slide switch, or jumper block on the back to set ID number. Some, like the Creative x2 CD-ROM drive let you click through 0-7. The Zip Drive lets you pick 5 or 6. (By the way, SCSI ID numbers have nothing to do with which Slot the SCSI interface card is in.)
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From: David Empson
SCSI ID 7 is usually special because the Apple SCSI and Hi-Speed SCSI cards count as a device set to ID 7 by default (and every Macintosh has a hard- wired SCSI ID of 7). The only thing that is special about ID 0 is that it is the standard ID used for an internal drive on a Macintosh.
There is no problem using SCSI ID 0 on an Apple II. On a RamFAST SCSI card, it is also safe to use SCSI ID 7 for a drive. The RamFAST doesn't have a SCSI ID, but every other SCSI card does.
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From: David Empson
004- What is "SCSI-2" and how is it different from SCSI-1?
For hard drives, "SCSI-2" basically means that the drive supports a stricter command set. The physical interface is usually identical.
For other device types, "SCSI-2" means a lot more, because the original SCSI standard didn't define much in the way of device types and command sets, so most devices use proprietary command sets. SCSI-2 standardises the command sets for most types of devices.
There are three special types of interface that you might see mentioned:
"Fast SCSI" supports data transfer at twice the speed of the original SCSI standard (10 MB per second vs 5 MB per second). This will not be a compatibility issue, as it is just the maximum transfer speed supported by the drive. The Apple II cannot transfer more than one megabyte per second.
"Wide SCSI" uses a different cable arrangement to double the width of the data path (16 bits instead of 8 bits). A wide SCSI drive cannot be used with an Apple II, unless it can also operated in "narrow" mode with the original 50-pin connector. (There is also "Fast Wide SCSI", which doubles the data rate and the width of the bus.)
"Differential SCSI" involves a different type of interface to the computer, where every data signal has a balanced positive and negative pair of wires, rather than a single wire and a ground line. I believe it has a different type of connector. Differential SCSI drives cannot be used with an Apple II."
Some drives use a proprietary connector, but the standard (narrow, non- differential) SCSI bus uses the same 50-pin connector for SCSI-1 and SCSI-2.
The only significant problem you might run into is termination, and supply of termination power. SCSI-2 devices tend to be fussier about termination than older devices.
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005- Will a SCSI-2 hard drive work with an Apple 2 system?
Usually, yes. I'm on my second Quantum drive that is described as "SCSI- 2".
There is a major caveat to this answer. Some newer drives require a host which implements the arbitration phase of the SCSI communication dialogue. The RamFAST doesn't do this, and as a result there are some drives that cannot be used with a RamFAST SCSI card. A notable example is the Quantum Fireball series. However; the Trailblazer and all older Quantum models work fine.
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006- I have a plain ol' Rev. C SCSI Card, will this work with a
SCSI-2 drive?
My Quantum LPS240 is working fine on an original Apple SCSI card.
Note: With the original Apple SCSI card, the card itself is not terminated, so if you are connecting more than one device, you need to add a second terminator between the computer and the first drive (using a "pass-through" external SCSI terminator, or internal termination on the first drive).
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007- What is SCSI "termination power"?
At least one device (SCSI card or any SCSI drive) must provide power for the SCSI terminators by feeding 5 volts onto the TERMPWR line on the SCSI bus.
Usually, termination power is fed through a diode to prevent backfeeding from a higher voltage source in case some other device is also supplying termination power. A good implementation will have a fuse to protect against shorts and a capacitor to cope with a sudden rise in termination power drain.
The Apple SCSI cards do not provide termination power (though some recent Apple Hi-speed SCSI cards were modified by Apple to provide termination power). The RamFAST SCSI card can supply termination power.
If a drive can supply termination power, I recommend letting it do so. The TERMPWR line can, in some cases, represent a significant load on the +5V rail going to the Slots. Both of my Quantum drive mechanisms provide termination power to the SCSI bus, avoiding the need to supply it from anywhere else.
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From: Rubywand
On the RamFAST SCSI RevC card, DIP switch #1 is set to ON to supply termination power. On other RamFAST SCSI cards, a jumper is placed at JP1 to supply termination power.
According to RamFAST documentation, it is okay to have the card set to supply termination power whether or not another device does with a few notable exceptions. If a connected hard disk (e.g. a Sider drive) has a sticker saying that the drive supplies termination power and that the interface must not, then the RamFAST must be set to _not_ supply termination power.
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From: LJSilicon
008- I just reinstalled System 6.0.1. Now every time I cold boot
I get this message 'RamFAST/SCSI is searching the SCSI bus
for devices..etc.' and have to wait several seconds. WEIRD?!
When you reinstalled the software, the RamFAST set itself for a long search. This is an option that you can change using the RamFAST utility. What it is doing is giving your scsi devices a chance to spin up. If you want a fast check, go to the options menu on the utilities and reset the Short Timeout option there to "YES".
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From: David Empson
009- I would like to make my own SCSI cable. Does anyone on csa2
know the pin-out for the standard 50-pin SCSI cable?
The cable pinout is documented in the technical reference manual for the Apple High-Speed SCSI card (and the original one as well).
This pinout is not a simple mapping from one end to the other; it is NOT easy to make one of these yourself. Apart from any issues of wiring errors, you also need a properly shielded cable to minimise noise being picked up or radiated. You should definitely not use a ribbon cable.
Here is the pinout, assuming I haven't made any typos (I can't see any).
DB-25 50-pin Function
1 49 -REQ
2 46 -MSG
3 50 -I/O
4 45 -RST
5 44 -ACK
6 43 -BSY
7 16,18,19 Ground lines
8 26 -DB0
9 20,21,22 Ground lines
10 29 -DB3
11 31 -DB5
12 32 -DB6
13 33 -DB7
14 1,2,3 Ground lines
15 48 -C/D
16 4,5,6 Ground lines
17 41 -ATN
18 7,8,9,11 Ground lines
19 47 -SEL
20 34 -DBP
21 27 -DB1
22 28 -DB2
23 30 -DB4
24 23,24,25 Ground lines
25 38 TERMPWR
The unlisted pins in the 50-pin connector (10, 12, 13, 14, 15, 17, 35, 36, 37, 39, 40, 42) are ground.
Note: the numbers for the 50-pin connector are counted along each row, like a Dsub-25. They are NOT the wire numbers in a ribbon cable.
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From: Steve Reeves
010- Is there some patch for SCSIHD.DRIVER to make it ignore
APPLE_DRIVER43 driver partitions?
Yes; you can change the counter in the string comparison routine that checks for the "Apple_Driver" partition type string so that it only checks the first 12 characters. This counter is at byte $3574 in the System 6.0.1 SCSIHD.DRIVER file and is originally $1F. Change this to $0B and the driver will then ignore "Apple_Driver43" partitions.
If you make this or any other patch to the driver, I also you recommend you bump up the version number. Change byte $01FF from $10 to $2E (for version 6.02 experimental).
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From: Harold Hislop
011- Someone told me there's supposed to be a bad bug in the
ROM 3.01e RamFAST. What is it?
Don't use the built in backup/restore in 3.01e!!! The restore opeation will nuke the partition map on the drive being restored to, as well as all existing partitions on that drive!
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From: Bradley VonHaden
012- What are correct HS SCSI settings, etc. for a Bernoulli drive?
My system is as follows:
ROM 1 Apple //gs
4mb AE RAM card
8mhz ZIP GS
Apple High-Speed SCSI card
90 mb Bernoulli hard drive
System 6.0.1
Three things I can think of to check:
One possibility is DMA compatibility. If your memory card is not DMA compatible, then switch 1 on the Apple HS SCSI card should be open (up).
Another possibility I guess is a SCSI ID conflict. The Apple HS SCSI card's ID at the factory is set to 7. Here are the Apple HS SCSI card switch combinations:
note1: Switch 1 controls DMA; open (up) turns DMA off
note2: Switches 2-4 control SCSI card ID
note3: 'U' means open (up), 'D' means closed (down),
'z' means Set for correct DMA (see note1)
SWITCH: 1234 1234 1234 1234 1234 1234 1234 1234
SETTING: zUUU zUUD zUDU zUDD zDUU zDUD zDDU zDDD
CARD ID: 0 1 2 3 4 5 6 7
Third, the scsi chain needs termination power to work properly. This is different from termination. Both are required for a properly functioning scsi chain. It is possible that neither the Bernoulli drive nor the Apple HS SCSI card is supplying termination power. If this is the case, and there is no other device on the scsi chain to supply said power, it probably won't work. There is a modification (requires soldering skills) to the Apple HS SCSI card to make it supply termination power.
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From: Jack Countryman IAC
013- I want to configure a CMS hard drive controller card to run a
20 meg drive for a //e. Could someone supply info on settings?
According to the CMS manual, page D3, the six sets of eight pairs of jumpers (u1....u6) are for the following purpose:
u 1: Boot Scan delay....manual shows no jumpers here in default
configuration
u 2: first (left) jumper is 'Enable I.C.P. (Yes/No)', middle 6 not
used, last (right) is 'multiple initiators (Yes/No)'...manual
shows no jumpers in default configuration
u 3: Selection phase time out delay....I believe this sets how long
the card waits for the drive to come up to speed(?)...manual
shows the default as having 4, 5, and 7 with jumpers installed
u 4: Arbitration phase time out delay....manual shows default as no
jumpers installed
u 5: Bus Free phase time out delay...manual shows default as jumper
on number 1
u 6: Interrupt recovery delay....manual shows jumpers on 3, 4,
and 5
J1 and J2 are single sets of pins. The manual says J2 is not used, but J1 is to be jumpered.
The card I have here, came out of a IIGS where it was hooked to first a twenty meg CMS drive, and later a forty meg CMS drive. It has the following jumpers set:
u1: jumper on 7
u2: no jumpers
u3: jumpers on 4, 5, and 7
u4: no jumpers
u5: jumper on 1
u6: jumpers on 3, 4, and 5
j2: no jumper
j1: jumper
As I recall, this setup yeilded a rather long pause for the hard disk to come up to speed (about 40 to 45 seconds) that we found necessary at the time to avoid boot problems.
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From: B.J. Major
014- Does it matter when I power-ON my SCSI hard disk?
From the Apple IIgs Owner's Reference, page 267:
"In order for the Finder to recognize a hard disk, the hard disk must be switched on and up to speed before you start up (or restart) the computer. Switch on the hard disk, wait about 10 seconds for it to come up to speed, and then restart the computer."
From the Macintosh User's Guide for desktop Macs, page 216:
"IMPORTANT: Always turn on any external SCSI devices connected to your Macintosh before turning on the computer itself. Otherwise, your computer cannot recognize the SCSI devices."
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From: Randy Shackelford
015- Can I leave SCSI devices I'm not using OFF when I turn ON my GS?
If it were not okay, I would have fried plenty of hardware. I do this all the time. I have seen no problems with having some devices off. As I have mentioned, I keep my magneto optical off most of the time; and, my buddy who uses my 700 now has a flatbed scanner and leaves it off most of the time. Both work fine.
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From: Daniel L. Miller
Related FAQs Resources: R008SCSITUT.TXT (text)
016- Is there a generic SCSI tutorial available for downloading?
Yes. Bus signals, commands, etc. for the Small Computer Serial Interface are described in the text resource file R008SCSITUT.TXT .
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From: Rubywand
017- What is the correct time-out setting for a Focus hard drive?
Supposedly, the purpose of having the Focus spin down and stop after 2, 10, or whatever minutes of idleness is to prevent over-heating and unnecessary wear. After a few days of trying various TO settings, I set my "Time Out" to "Never" and have had no problems with over-heating or crashes even after many all-day sessions.
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From: Harold Hislop, Dan Brown, Rubywand
Related FAQs Resources: R009SCSIMOD.GIF (GIF pic)
018- How do I modify my Apple Computer High-Speed or Rev C SCSI
card to supply Termination Power?
The Termination Power modification for Apple SCSI cards consists of adding a diode. The mod for each card is shown in resource file R009SCSIMOD.GIF.
The High-Speed card pic shows a simple sketch of the back of the Apple High Speed SCSI card near connectors 26-33. The directions say that you connect a 1N914 diode between two points:
The anode (non-banded end) of the diode goes to the *top* of L1. The cathode (banded/striped end) of the diode goes to the >bottom< of RP2
The pic shows the *top* of L1 to be a solder pad (just a solder pad with no trace showing) a little ways up from a point between connectors 32 and 33.
The >bottom< of RP2 is just a bit up and to the left of the *top* of L1. It is the lowest of several points (the pic shows 8) arranged in a vertical column and should have a trace going off to the left.
The other pic shows where to connect the diode on an Apple Rev C SCSI card.
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From: Scott G
019- Can I get a Focus drive bigger than a couple hundred MB?
Get a 40MB Focus Hard Card from Alltech. Get an 800MB IDE 2.5" Quantum GO-drive from Computer Shopper sources for pennies. Replace the original drive on the Focus Hard Card with the big one (VERY easy and self-explanatory, just use a screw driver). Low level format, partition, and high level format. That's it!
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From: Gary Black
020- On my ROM-03 GS the hard disk is connected to a CMS SCSI card.
How do I install System 6.0.1?
It turns out that the SCSI drivers that come on the Sys 6.0.1 Install Disk downloaded from ftp.apple.com are incompatible with CMS ver 3.0 (and probably earlier) SCSI cards.
What I did was to replace scsi.manager and scsihd.driver in the System 6.0.1 Install disk SYSTEM/DRIVERS folder with scsi.manager, scsihd.driver, AND CMS.driver from the CMS Utility disk.
With the replacement scsi drivers installed, the Install disk recognizes the hard drive and installation went smoothly from that point. (The CMS files are dated 1989 and 1990, so they are a bit older than the 6.01 files, which are dated 1993. But, they work!)
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From: Scott G
021- How is DMA set for SCSI cards with 8MB RAM cards on the GS?
DMA needs to be turned off with the Apple HS SCSI card or the RamFAST revision C card. It does not need to be turned off with the RamFAST revision D card (differentiated by being half sized). Current RamFAST cards are revision D as are late model CV Tech cards. It is the RamFAST revision D that is designed to DMA into any RAM card, even 8MB models. It was made around the time of the CV RAM 8MB model that turned into the RAM GS Plus, but functions just as well with the Sirius card.
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From: Louis Cornelio
022- My 20MB Focus bombs and there's some goo on the card. A fix?
The goo is leaking from the drive due to a failed seal which seems to plague some of the older Conner drive modules. The fix is to check with the seller of the drive for a replacement. At Alltech, a good Apple II person to contact is Tony Diaz.
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From: Joe Walters
023- Where can I find the RamFAST manual on the net?
The Apple High Speed SCSI card has a set of Dip Switches on it; the Rev C doesn't, and the ROM chip date is older than 1989, if it shows at all. The Apple SCSI cards older than REV C don't work in my IIe or IIgs......
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From: Supertimer
The Apple High Speed SCSI card has a printed label on one of the chips showing the name "Sandwich II" on it.
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From: David Empson
The ROMs for the three (non "High Speed) Apple SCSI card firmware revisions are ...
341-0112A revision A firmware
341-0112B revision B firmware
341-0437-A revision C firmware
There is only one firwmare revision for the high-speed card
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From: Patrick Schaefer and Dakin Williams
025- Where can I find Profile maintenance and formatting info?
See the ProfileHardDriveMaintenance.txt file on Ground at ...
