OKIDATA DOC-IT3000, Руководство по обслуживанию

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module on the Controller.
The communications between the PC and the Controller is achieved by using a Page Frame
technique which is used by Expanded Memory Manager (EMM) implementations. By using this
technique, any segment of the controllers memory can be mapped and accessed directly from the
PC host side.
The default segment used by the Doc-It system is 0xD0000-0XD3FFF. Since this address is
widely used by a number of PC add-on products, users have the option to choose another page
frame which is not used by someone else. As soon as the page frame is determined, the Doc-It
system will use it to transmit and receive data/messages/status between the PC and the
Controller.
The OkiPort (addresses between 0x200 and 0x3FF) are registers used to program the system
working environment. One of the examples is to program which page frame is going to be used for
PC-Controller communication as described above.
The Okiselect registers (0xE3BF, 0xE378, 0xE372 and 0xE20F) are used to store the information
of the OkiPort configuration, which is referenced by Controller hardware each time upon power
up. One of these registers is selected by the user at the time of installation. The value of these
registers selected by the user has to match the OkiPort settings on the Controller board, since the
settings that users make will be referenced by the Doc-It system software only. The position of the
OkiPort jumpers is the only means for the Controller hardware to know where to look for this
information.
TSR Module
Communications between the PC host and the Controller is done through a TSR program which
resides on the host computer. There is only one way to communicate to the Controller, and that is
through this TSR program. This prevents conflict during communication and gives total control to
only one module. Not only will the communication be bulletproof but also, if there are any changes
in the future, hardware or software, it will only be necessary to modify the TSR program.
The TSR consists of three modules:
· Low-level API (i.e. software interrupt handler) for handling the communication between
the high level API and the Controller.
· IRQ interrupt handler (a hardware interrupt generated by the Controller) to receive the
message from the Controller.
· Timer interrupt handler (timer clicks generated by the PC hardware) to handle the disk
read/write operations (Disk I/O) requested by the Controller.
Host I/O Module
The Host I/O module on the Controller will be called up by the host interrupt (e.g. INT
0x62...0x67). The TSR sends messages to the incoming message queue on the Controller
memory and then the Host I/O module gets the commands from the incoming queue. The Host
I/O module will identify the function calls and call up the tasks (Fax, Scan, Print and Copy)
accordingly.
The Host I/O is also responsible for sending the message and the status back to the PC host
using the hardware interrupt (IRQ 10, 12, 15). If one of the tasks needs to send a message or
status to the host, it will send a message to the outgoing message queue first and then call up the
Host I/O module. The Host I/O module will generate the IRQ interrupt to signal the PC host that