HP LaserJet 4 Service Manual - Page 124

Formatter System The formatter is responsible for the following: • Receiving and processing ASCII data from printer interfaces. • Monitoring front panel input and relaying printer status information (through the front panel and bi-directional I/O). • Developing/coordinating data placement and timing with the print engine. • Storing font information. • Communicating with the host computer. The Formatter PCA can be divided into three functional areas: • I/O Control • Memory/Memory Management • Data Processing Formatter Feature LaserJet 4 Processor 20 MHz 80960KA REt Yes MEt No Economode No Configurable I/O Buffer Size No Personality Resource No Saving PowerSave Mode No Font Cartridge Slot Yes MIO Interface Level 5.0 Serial Ports RS-232/422 Parallel Port Bitronics Maximum RAM (PCL/PS) 34/22 MB SIMM Support RAM/ROM PCL Level 5 On-Board Fonts 35 Intellifont/10 TT Line Printer Default Symbol Set Roman-8 Paper Size Support Letter/Legal/A4/Exec MP (Tray 1) Modes First, Manual, Cassette Grayscale Hardware Assist No ROPS 3 Hardware Assist No Intuitive Control Panel No LaserJet 4+ 25 MHz 80960KB Yes Yes Yes Yes Yes Yes Yes 5.1 RS-232 IEEE-1284 Bitronics 66/50 MB RAM/ROM 5E 35 Intellifont/10 TT Line Printer Roman-8 Letter/Legal/A4/Exec First, Manual, Cassette No No No LaserJet 5 33 MHz 80960JF Yes Yes Yes Yes Yes Yes No 6.0 RS-232 & SIR IEEE-1284 Bitronics 66/52 MB RAM/ROM/Flash 6 45 TT & Dark Courier Line Printer PC-8 Letter/Legal/A4/Exec/A5 First, Cassette Yes Yes Yes I/O Control The formatter I/O control is responsible for maintaining communications with the host system(s). The printer has three interfaces; serial, parallel (bitronic), and Modular I/O (MIO). The formatter maintains connections with hosts connected to these I/O's including accepting data handshaking, and returning status. 5-12 Functional Overview