.The official Csa2 (comp.sys.apple2) Usenet newsgroup Apple II FAQs
  originate from the.II Computing Apple II site,1997-2017.
  Csa2 FAQs text file ref. Csa2HDNSCSI.txt  rev225 December 2016

    Hard Disks & SCSI Interfaces
.      ......
                 also see CD-ROM  and  Zip Drives

 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 pinout 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 SCSI 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.


002- What kinds of hard drive systems are available for Apple II

     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 from Sequential
Systems. 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
- allows up to 8 devices to be added to the chain
- allows up to 12 partitions to be active at any one time
- 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


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.


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.)


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.


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

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.


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

     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.


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).


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.


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.


From: LJSilicon

008- I just reinstalled System 6.01. 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".


From: David Empson

009- I would like to make my own SCSI cable. Does anyone on csa2
     know the pinout 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.

I repeat that 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

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 DB-25.  They are NOT the wire numbers in a ribbon cable.


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).


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!


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

 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
 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.


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 for the 1990 ROM, the six sets of eight pairs of
jumpers (u1....u6) are for the following purposes.

Note: This description of the jumpers is only true for the 1990 ROM. On the
1987 ROM the jumpers have a different usage.

   /                                                               |
  /     u 1          u 2            u 3            u 4       j2    |
 /                                                                 |
/                                                                  |
|                                                                  |
|                                                                  |
|                                                                  |
|                                                                  |
|                                                                  |
|    u 5     u 6                                                  |
|___________________________________________                    j1 |
                                            |                      |

u 1: Boot Scan delay....manual shows no jumpers here in default

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 (for use with 1990 ROM only):

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.


From: Andrew Roughan

The CMS SCSI card has three ROM revisions.

The 1987 ROM uses jumpers on the card to define the
partitions on the drive. These partitions cannot be
greater than 32MB and only two partitions are
supported. The manual should be considered a MUST

The 1989 ROM is similar to the 1987 ROM in
functionality, but it has an annoying habit of
shutting down the drive after a period of inactivity.
It needs an access attempt to start it up again, but
this access will return a failure error code (ok when
you can redo the action but not too good otherwise :).
A plus in its favour is that the jumper settings are
available from the utility software. Because of this,
the manual is not a necessity.

The 1990 ROM gets around the problem of jumper based
partitions by assuming that each partition on the
drive will be 32MB (or as much as is left less than
32MB). This ROM will therefore support > 60MB of
storage on multiple drives. The drawback is that only
two partitions can be accessed at a time. The ROM
supports switching them in and out at boot time (hold
down the Open Apple key). The jumper settings are once
again available in the utility software.

For the sake of compatibility with the Apple Partition
Map,  (do you wish to use the same drive on a RamFAST
or Apple SCSI card? or on a Macintosh?) the CMS SCSI
card should not be considered.

However if you just wish to access one 60MB SCSI hard
drive from an Apple II, then the CMS card will do the
job well.

The CMS SCSI card has one advantage over the RamFAST
and Apple SCSI cards. It can be used to share a hard
drive between computers. For example it is possible to
use two 1989 ROM cards (in an Apple //e and a //gs) to
share a 60MB drive with a second //gs which has a 1990
ROM card.

The CMS utilities disks for all ROM versions are
available on the following mirror of the ground



I also scanned in the manual for the 87 ROM and currently host it here:

The manual is also available on GSWV at
http://apple2.org.za/gswv/a2zine/Docs/ .

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."


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.


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 .


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.


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.


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!


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!)


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).  The latest 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 Sequential's RAM GS Plus, but
functions just as well with the Sirius card.


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.


From: Joe Walters

023- Where can I find the RamFAST manual on the net?

     You can find the RamFAST manual at ...

http://apple2.org.za/gswv/a2zine/Docs/RamFASTManual.txt (Text file)
Ground: /Docs/(.BSQ binscii file)
ftp://apple2.tffenterprises.com/pub/apple2/miscinfo/(.BXY ShrinkIt file)


From: Chuck Newby

024- How can I tell which Apple SCSI card I have?

     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......


From: Supertimer

     The Apple High Speed SCSI card has a printed label on one of the chips
showing the name "Sandwich II" on it.


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


From: Patrick Schaefer and Dakin Williams

025- Where can I find Profile maintenance and formatting info?

     See the ProfileHardDriveMaintenance.txt file on Ground.