2.2PS Board (OKIPAGE 6ex option)
The PS board consists of two Program & Font ROM's, DRAM's, an EEPROM, and a host interface circuit.
(1)Program & Font ROM's
The Program & Font ROMs store the PostScript Level II program and its fonts. Mask ROM is used for the Program & Font ROMs.
(2)DRAM
0.5MB of DRAM's reside on the PS board.
(3)EEPROM
4.096
(4)Local Talk I/F
Apple Talk protocol data is received from the host system via LocalTalk interface. The block diagram is shown in Figure
(5)SIMM Socket
One SIMM Socket is mounted on the PS board.
Program & Font
ROM
4MB Mask ROM
LocalTalk I/F (RS422 I/F)
Resident RAM
(0.5MB)
SCC
85C30
SIMM
Socket
EEPROM
(4K)
Figure 2-3 PS Board Block Diagram
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