DaynaPort SCSI Link: SCSI Command Set
Original version Copyright 2002-2005 by Roger Burrows.
The current version is made available under Creative Commons BY-SA. For additional information, see the end of this document.
Some reference data captures are available here:
https://github.com/piscsi/PiSCSI/tree/daynaport/doc/data_captures/daynaport
SCOPE
This document applies to the following hardware devices:
- DaynaPort SCSI/Link-T (Model DP0801)
- DaynaPort SCSI/Link-3 (Model DP0802)
and to the following firmware revisions:
- 1.4a
- 2.0f
It probably also applies to other firmware revisions; it may also apply to other Dayna SCSI/Link devices. Any feedback on this is welcomed.
All numbers are expressed in hexadecimal, unless otherwise noted.
COMMAND SET SUMMARY
The following is a partial list of implemented SCSI commands:
- 03 Request Sense
- 08 Read
- 09 Retrieve Statistics
- 0a Write
- 0c Set Interface Mode / Set MAC Address
- 0d Multicast Enable Command
- 0e Enable/disable Interface
- 12 Inquiry
A number of other SCSI commands are implemented, but their usage is not yet fully known.
Multicast Enable Command (0d)
Command: 0d 00 00 00 06 00
Function: Configures the DaynaPort SCSI/Link to accept/reject multicast address.
Type: Input (Transitions to DATAOUT)
Host then sends: 00 09 00 07 FF FF FF 00 (The last 00 might not actually be there?)
Note: The AppleTalk broadcast address is 09:00:07:ff:ff:ff.
This is configuring the Multicast Address Registers of the DP83902A Ethernet receiver inside the DaynaPort SCSI Link
10.9 MULTICAST ADDRESS REGISTERS (MAR0 –MAR7)
The multicast address registers provide filtering of multicast
addresses hashed by the CRC logic. All destination addresses
are fed through the CRC logic and as the last bit of the
destination address enters the CRC, the 6 most significant bits
of the CRC generator are latched. These 6 bits are then decoded
by a 1 of 64 decode to index a unique filter bit (FB0 –63) in
the multicast address registers. If the filter bit selected is
set, the multicast packet is accepted. The system designer
would use a program to determine which filter bits to set in
the multicast registers. All multicast filter bits that
correspond to multicast address accepted by the node are then
set to one. To accept all multicast packets all of the
registers are set to all ones.
Enable/disable Interface (0e)
Command: 0e 00 00 00 00 XX (XX = 80 or 00)
Function: Enable (80) / disable (00) Ethernet interface
Type: No data transferred
Notes: After issuing an Enable, the initiator should avoid sending
any subsequent commands to the device for approximately 0.5
seconds
Inquiry (12)
Command: 12 00 00 00 LL 00 (LL is data length)
Function: Perform a standard SCSI Inquiry command: reference the
SCSI spec for further information
Type: Input; reference the SCSI spec for the data returned
Example Response:
|Byte Num|Value|Decoded| | |Byte Num|Value|Decoded| | |Byte Num|Value|Decoded|
|--------|-----|-------|—|--------|-----|-------|—|--------|-----|-------|
|0 | 03| Peripheral Type = 3 (CPU)||| 16| 53| S ||| 32| 31| 1 |
|1 | 00| ||| 17| 43| C ||| 33| 2E| . |
|2 | 01| SCSI Version 1 ||| 18| 53| S ||| 34| 34| 4 |
|3 | 00| ||| 19| 49| I ||| 35| 61| a |
|4 | 1E| Additional Length = 30 ||| 20| 2F| / |
|5 | 00| ||| 21| 4C| L |
|6 | 00| ||| 22| 69| i |
|7 | 00| ||| 69| 6E| n |
|8 | 44| D ||| 24| 6B| k |
|9 | 61| a ||| 25| 20| (sp) |
|10| 79| y ||| 26| 20| (sp) |
|11| 6E| n ||| 27| 20| (sp) |
|12| 61| a ||| 28| 20| (sp) |
|13| 20| (sp) ||| 29| 20| (sp) |
|14| 20| (sp) ||| 30| 20| (sp) |
|15| 20| (sp) ||| 31| 20| (sp) |
Notes:
- The length is user-selectable to a maximum of 25 (37 decimal)
- Some tools send other SCSI lengths. Example: SCSIProbe on 68k Macs has a length of 05
Read (08)
Command: 08 00 00 LL LL XX (LLLL is data length, XX = c0 or 80)
Function: Read a packet at a time from the device (standard SCSI Read)
Type: Input; the following data is returned:
LL LL NN NN NN NN XX XX XX … CC CC CC CC
where:
LLLL is normally the length of the packet (a 2-byte
big-endian hex value), including 4 trailing bytes
of CRC, but excluding itself and the flag field.
See below for special values
NNNNNNNN is a 4-byte flag field with the following meanings:
FFFFFFFF a packet has been dropped (?); in this case
the length field appears to be always 4000
00000010 there are more packets currently available
in SCSI/Link memory
00000000 this is the last packet
XX XX ... is the actual packet
CCCCCCCC is the CRC
Notes:
- When there is no data to be received, the DaynaPort will respond by going to the DataIn phase snd sending 00 00 00
- When all packets have been retrieved successfully, a length field of 0000 is returned; however, if a packet has been dropped, the SCSI/Link will instead return a non-zero length field with a flag of FFFFFFFF when there are no more packets available. This behaviour seems to continue until a disable/enable sequence has been issued.
- The SCSI/Link apparently has about 6KB buffer space for packets.
Example:
Sending an ARPING to the Mac host from an attached Linux device.
- Raw ARPING Data:
``00 80 19 10 98 e3 dc a6 32 1c 4e 69 08 00 45 00``
``00 1c dc 51 00 00 40 01 76 a7 a9 fe 7d ea ff ff``
``ff ff 08 00 1b aa dc 51 00 04 00 00 00 00 00 00``
``00 00 00 00 00 00 00 00 00 00``
-
Read request command:
08 00 00 05 F4 C0 -
Mac’s response (DATAIN):
``00 40 00 00 00 00`` *Length & Flag fields* ``00 80 19 10 98 e3 dc a6 32 1c 4e 69 08 00 45 00`` ``00 1c dc 51 00 00 40 01 76 a7 a9 fe 7d ea ff ff`` ``ff ff 08 00 1b aa dc 51 00 04 00 00 00 00 00 00`` ``00 00 00 00 00 00 00 00 00 00`` ``a1 85 ed ff 5b`` *CRC*
Request Sense (03)
Command: 03 00 00 00 00 00
Function: Perform a standard SCSI Request Sense command
Type: Input; reference the SCSI spec for the data returned
Notes:
- This command always transfers exactly 9 bytes of data (note that cdb byte 4 is always zero, however).
- If the sense key is 5, the driver should reinitialise the device via a disable/enable sequence; otherwise, it need do nothing.
Retrieve Statistics (09)
Command: 09 00 00 00 12 00
***(akuker note)***: `09 00 00 00 06 00` was observed during hardware diagnostics
Function: Retrieve MAC address and device statistics
Type: Input; returns 18 (decimal) bytes of data as follows:
- bytes 0-5: the current hardware ethernet (MAC) address
- bytes 6-17: three long word (4-byte) counters (little-endian).
Notes:
- The contents of the three longs are typically zero, and their usage is unclear; they are suspected to be:
- long #1: frame alignment errors
- long #2: CRC errors
- long #3: frames lost
Set Interface Mode (0c)
Command: 0c 00 00 00 FF 80 (FF = 08 or 04)
Function: Allow interface to receive broadcast messages (FF = 04); the
function of (FF = 08) is currently unknown.
Type: No data transferred
Notes: This command is accepted by firmware 1.4a & 2.0f, but has no
effect on 2.0f, which is always capable of receiving broadcast
messages. In 1.4a, once broadcast mode is set, it remains set
until the interface is disabled.
Set MAC Address (0c)
Command: 0c 00 00 00 FF 40 (FF = 08 or 04)
Function: Set MAC address
Type: Output; overrides built-in MAC address with user-specified
6-byte value
Notes: This command is intended primarily for debugging/test purposes.
Disabling the interface resets the MAC address to the built-in
value.
Write (0a)
Command: 0a 00 00 LL LL XX (LLLL is data length, XX = 80 or 00)
Function: Write a packet at a time to the device (standard SCSI Write)
Type: Output; the format of the data to be sent depends on the value
of XX, as follows:
if XX = 00, LLLL is the packet length, and the data to be sent
must be an image of the data packet
if XX = 80, LLLL is the packet length + 8, and the data to be
sent is:
PP PP 00 00 XX XX XX ... 00 00 00 00
where:
PPPP is the actual (2-byte big-endian) packet length
XX XX ... is the actual packet
Hardware Diagnostics
When the DaynaPort Hardware Diagnostics tool is executed, the following behavior is observed:
- The SCSI bus is scanned for all SCSI IDs, but doing a Selection and waiting for the device to respond. This will go from SCSI 6..0
- When a device responds to the selection, a 0E (Enable/Disable Interface) command is sent to the SCSI device, with the last byte set to 00 (indicating that the device should be disabled).
- The SCSI bus is scanned a second time, with an Inquiry command (12). This time, the scan will stop when the DaynaPort device is detected.
- Next, the host will send a Retrieve Statistics (09) command to the DaynaPort. 09 00 00 00 06 00
- The DaynaPort will respond with the requested data - 18 bytes long 00 80 10 FB E3 00 00 00 ... (Note: scsimon wasn’t able to accuratly capture the REQ/ACK signals - so I’m only assuming the response was 18 bytes long)
- The host will then send an INQUIRY command to the DaynaPort 09 00 00 00 12 00
- The DaynaPort will respond with 80 19 10 FB E3 00 00 00 00
- The host will send the Enable/Disable Interface command (0E) with the last byte set to 00 (indicating the device should be disabled)
After this, Hardware Diagnostics tool will wait for the user to reboot the Mac.
Software Diagnostics
When the Software Diagnostics application is launched, it appears to only send a Request Statistics (09) command to the DaynaPort. 09 00 00 00 12 00
The DaynaPort appears to respond with the standard 18 byte response. For example: 80 19 10 98 E3 00 00 00 00 ...
The statistics information doesn’t appear to be reported anywhere (that I can find).
Mac Startup Sequence
At startup, the Mac will issue a Read command (08) (08 00 00 00 01 00). The target will then respond by going into the status state with data of 02, followed by a MSGIN of 00
========================= END OF DOCUMENT =========================
Document History
The original version of this document was distributed by Roger Burrows with the following copyright information:
Copyright 2002-2005 by Roger Burrows. All Rights Reserved. Permission is granted to copy this document providing that no changes are made to the contents.
LIMITATION OF LIABILITY AND DISCLAIMER OF WARRANTY
The information contained in this document is provided "as-is", without warranty of any kind, expressed or implied, including without limitation any warranty concerning the accuracy, adequacy, or completeness of such information or material. The Author shall not be responsible for any claims attributable to errors, omissions, or other inaccuracies in the information or material contained in this document, and in no event shall the Author be liable for direct, indirect, special, incidental, or consequential damages arising out of the use of such information or material.
akuker has contacted Roger Burrows and has received permission to modify and re-distribute this information. The Creative Commons (CC BY-SA) license is currently used to distribute this documentation.
The original revision history of this document follows:
- Version 1.00 (8/August/2002) Original version
- Version 1.10 (22/April/2005) Added description of ‘Set Interface Mode/Set MAC Address’ command
- Version 1.20 (16/July/2005) Corrected description of ‘Set Interface Mode/Set MAC Address’ command
The current version history of this document is maintained in the PiSCSI Github Wiki at: https://github.com/piscsi/piscsi/wiki/Dayna-Port-Command-Set
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