hpoj reference: ptal-photod
The ptal-photod daemon implements the
"floppyd" network protocol. Its purpose is to let you use
as a portable method for reading and writing files on
photo cards inserted in hpoj-supported multi-function peripherals. Such
photo cards are normally formatted with an MS-DOS FAT or VFAT file system.
Click here for more information on
setting up photo-card access
with the hpoj software.
The ptal-photod command-line syntax is as follows:
ptal-photod devname [options...]
Recommended options: one (but usually not both) of the following:
Other possible options (not necessary in most cases):
- -maxaltports n -- tries up to n (for example, 26)
successive TCP/IP ports if the desired or default TCP/IP port address is
already in use, presumably by another ptal-photod or floppyd
- -portoffset n -- the desired TCP/IP port offset (default=0)
relative to the TCP/IP base port (see -baseport below)
- -bindto IPaddress -- binds to specified TCP/IP address
- -bindtoall -- binds to all TCP/IP interfaces
- -baseport n -- sets TCP/IP base port (default=5703)
- -tcpport n -- binds to TCP/IP port n (default=baseport+portoffset)
- -readonly -- disables writes
- -readwrite -- enables writes (default)
- -nofork -- runs in foreground (default is background daemon)
- ptal-photod logs startup and error messages to syslog
(/var/log/messages) in addition to logging to standard error.
- ptal-photod currently only supports photo cards which were
formatted with 512 bytes per sector.
- ptal-photod is somewhat slow, especially on older models,
because it currently reads/writes only one sector at a time when presented
with a multiple-sector request from
- The floppyd protocol was originally designed for accessing
local floppy drives from a remote system you have logged into and set your
X-Windows display back to your local system. As a consequence,
expects to find "X cookie" authentication information for each X display
number which corresponds to a remote drive, even though ptal-photod
doesn't use this information. If
gives some sort of "authentication failed" error message with a given drive
letter (for example, R:) and display number (for example, ":2"),
then run the command "xauth add :2 . 00", substituting the
correct display number in place of ":2".
- If you use the -bindto or -bindtoall options
to make the device's card-reader functionality available to other
network clients, then be careful to set up an appropriate firewall to
prevent untrusted clients (such as on the public Internet) from accessing
- If your device provides a standard USB mass-storage interface, you may
get better performance and usability if you use that access method instead of
and ptal-photod, because it allows you to mount the card as a VFAT
file system and use a wide variety of Linux/Unix file-management tools.
- If you kill and restart ptal-photod (presumably via
"ptal-init start") too quickly, then
sometimes ptal-photod is restarted before the old instance's TCP
port is fully released, which may cause the new instance to use a different
TCP port, which will map to a different drive letter, or to fail to start
altogether. As a workaround,
"ptal-init start" delays before
starting the first instance of ptal-photod, but if this isn't
enough and this problem still occurs for you, then consider splitting the
"restart" operation into separate "stop" and "start" steps to give extra
time for the TCP port to get fully released.
Given the following lines in /etc/mtools.conf (for all users) or
~/.mtoolsrc (for specific users):
drive p: file=":0" remote
drive q: file=":1" remote
drive r: file=":2" remote
drive P: will be mapped to port 5703 on the local system,
drive Q: will be mapped to port 5704, and
drive R: will be mapped to port 5705.
- If you start ptal-photod as follows:
ptal-photod mlc:usb:PSC_900_Series -maxaltports 26
ptal-photod mlc:usb:PHOTOSMART_100 -maxaltports 26
then mlc:usb:PSC_900_Series will be bound to port 5703 and therefore
drive P:, and mlc:usb:PHOTOSMART_100 will be bound to port 5704 and
therefore drive Q:, because of the order in which the two instances of
ptal-photod are started. Drive R: will not have anything bound to it.
- If you start ptal-photod as follows:
ptal-photod mlc:usb:PSC_900_Series -portoffset 1
ptal-photod mlc:usb:PHOTOSMART_100 -portoffset 0
ptal-photod mlc:usb:officejet_d_series -portoffset 1 # Will fail.
then mlc:usb:PSC_900_Series will be bound to port 5704 and therefore
drive Q:, and mlc:usb:PHOTOSMART_100 will be bound to port 5703 and
therefore drive P:, because specific port offsets relative to port 5703 were
specified. However, the above invocation for
mlc:usb:officejet_d_series will fail, because the
"-portoffset 1" switch conflicts with that of
mlc:usb:PSC_900_Series. In order to safeguard against failures
due to inadvertently specifying the same -portoffset twice,
you can still also specify something like "-maxaltports 26",
which would have made mlc:usb:officejet_d_series roll over to
port 5705 and therefore drive R:.