Star Micronics 150 manual Printer Buffer Size, Parallel Port Inquire Ieee

Programmer's Guide	PcOS Series 150	Communications
		Parallel Port
Printer Buffer Size

The Series 150 Printer has a configurable buffer size. It can be set from 256 bytes to 6144 bytes. This allows an application to control how far ahead of the printer it can get. The smaller the buffer is, the tighter the control will be. It is up to the application developer to select the optimal buffer size.

One-line mode

The Series 150 Printer supports a one-line mode of operation. In this mode, the input buffer is set to 1024 bytes; however, the printer will go busy after every [CR] received. In this mode, the printer will stay busy after the [CR] is received and remain busy until the previous information is printed. Several features must be considered when using one-line mode.

1.The printer only looks at [CR]’s. [LF] will cause the printer to print but will not set busy.

2.If a [CR] character is received as part of another command, i.e, as part of graphics data, the printer will go busy after the [CR] is received, but will go ready after the [CR] is processed.

3.By definition, one-line mode is slow. The printer will not allow the application to get ahead of the printer.

Parallel Port Inquire IEEE 1284

The Series 150 Printer supports the IEEE 1284 bidirectional parallel peripheral interface standard. This standard provides for a bidirectional link on the parallel port. The Series 150 Printer supports Modes 0 and 4 only. This provides a nibble mode reverse channel for printer identification and status inquire command. It is beyond the scope of this guide to describe the IEEE 1284 protocol. The complete specification is available from:

The Institute of Electrical and Electronic Engineers, Inc.

345 East 47th Street

New York, NY 10017, USA

Buffer

The Series 150 Printer has a 256-byte buffer that contains information to be returned by the IEEE 1284 reverse link. Information is placed in this buffer in the same format as RS-232 serial information is returned.

Inquire commands sent to the printer in IEEE 1284 mode will place responses to the commands in the IEEE 1284 reverse channel buffer. This buffer is then transmitted to the host when the host requests the reverse channel.

Mode 4

Mode 4 provides for the printer to return identification information to the host system. The Series 150 Printer returns:

xx,yy (length of following data, 2 bytes with msb first) MANUFACTURER: Ithaca-Peripherals;

COMMAND SET: IPCL; MODEL:150; COMMENT: Rev. x.xx;

ACTIVE COMMAND SET: IPCL;

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