Apple 310 manual Basic Operation, Dram Expansion, Batch Mode

C H A P T E R 1

LaserWriter Select 310 Hardware

DRAM Expansion 1

The LaserWriter Select 310 printer comes with 1.5 MB of DRAM installed on the printer’s main circuit board. As shown in Figure 1-6, there are three DRAM devices: two 512K x 8 bit devices, and one 256K x 16 bit device. These three DRAMs present a 16-bit interface to the microprocessor installed on the printed circuit board.

You can expand DRAM capability by adding a 72-pin SIMM (single in-line memory module), which plugs into the SIMM connector on the circuit board. The LaserWriter Select 310 printer supports SIMM cards with capacities of 1 MB and 4 MB. You must use a 32-bit wide SIMM card in this configuration.

Basic Operation 1

This section provides an overview of the LaserWriter Select 310 printer’s operating modes. Since much of the printer’s behavior may be changed by changing the parameter settings, as described in Chapter 2, this section assumes that all options that may be adjusted are set to their standard values.

The main function of the LaserWriter Select 310 printer is to execute the PostScript language programs sent to it from a computer. During normal operation, the printer cycles endlessly through the following sequence of steps:

1.It sets up a clean initial execution environment (virtual memory) for the PostScript language program. In effect, it is setting up a job.

2.It executes the job by interpreting the standard input files, which are received on either the serial port or on the Centronics parallel port.

3.When the printer encounters an end-of-file character or when an error occurs, it cleans up after the job and restores the virtual memory to its initial state in preparation for the next job.

The main object of this process is to produce printed pages. However, a program may change some permanent parameters in the printer itself, or it may perform some computation that causes results to be sent back to the host computer, rather than causing hard copy to be printed.

There are two basic modes of operation: batch and interactive.

Batch Mode 1

Batch mode is the normal way of operating the LaserWriter Select 310 printer . In this mode it operates as a printing device for a computer.

A batch-mode job consists of executing a single file containing a PostScript language program. When an end-of-file character is reached, or the PostScript language terminates, the job is finished. In this mode, the only data transmitted from the LaserWriter Select 310 printer to the host is generated by the PostScript language printer operator or by errors. The printer provides no echoing, editing, or other user amenities.

10 Basic Operation