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Z80-MEMORY(3)			 Memory	access			 Z80-MEMORY(3)

NAME
       init_banks(),  reset_banks(),  bank_port(),  switch_bank(),  clear_mem-
       ory(),	 memory_at(),	 read_addr(),	 read_memo(),	 write_memo(),
       write_to_memory(), dma_write(), dma_read() - total memory access

SYNOPSIS
       #include	<stdio.h>

       int init_banks(char *rom_path, char *bank_mapping_descr);

       void reset_banks(void);

       unsigned	 bank_port(unsigned char id);

       void switch_bank(unsigned char id, unsigned i);

       void clear_memory(void);

       unsigned	char memory_at(unsigned	short index);

       unsigned	char * io_address;

       unsigned	char read_addr(unsigned	short index);

       unsigned	char read_memo(unsigned	short index);

       void write_memo(unsigned	short index, unsigned char data);

       unsigned	 char  write_to_memory(unsigend	 short	index,	unsigned  char
       data);

       unsigned	 dma_write(unsigned short offset, unsigned count, FILE *from);

       unsigned	 dma_read(unsigned short offset, unsigned count, FILE *to);

DESCRIPTION
       These functions provide all memory  access  and	also  read  data  from
       external	hardware.

       init_banks
	      initializes  the	bank handling and reads	the bank contents from
	      the directory *rom_path with the file  *bank_mapping_descr  con-
	      taining  the  bank mapping description. It returns the number of
	      usable bank entries in the description file.

       reset_banks
	      does a reset to the banks	meaning	going to the default  initial-
	      ization.

       bank_port
	      can  be  used  to	 test  a  port whether it is reserved for bank
	      switching.  If this is the case it  returns  the	positive  bank
	      port no else 0.

       switch_bank
	      switches the bank	id into	memory at the position defined by bank
	      port no i.

       clear_memory
	      sets these parts of the 64kB RAM to 0 which are writeable.

       memory_at
	      returns  the byte	value at position index	in the memory. Can not
	      be used by the decoding or execution unit	of the CPU because  it
	      by-passes	the CPU.

       io_address
	      holds the	location of an external	supplied byte by the hardware.

       read_addr
	      returns  the  byte value correspoing to the address index.  This
	      may be an	IO-address in which case io_address is just to	locate
	      the byte.

       read_memo
	      returns  the  byte  value	 correspoing to	the address index from
	      memory.

       write_memo
	      writes the byte value data into memory at	address	index provided
	      this address is writeable.

       write_to_memory
	      writes the byte  value  data  to	address	 index	provided  this
	      address  is  writeable.  It  returns  the	 previous value	at the
	      address. This function can not be	used  by  the  execution  unit
	      because  it by-passes the	CPU. It	is demanded from compile(void)
	      which is called from z80-mon.

       dma_write
	      transfers	into memory starting  at  address  offset  count  many
	      bytes directly from file from by passing the CPU.

       dma_read
	      transfers	 from  memory address offset count many	bytes directly
	      into file	to by passing the CPU.

SEE ALSO
       z80-memory(5), z80-banks(5)

Z80-MEMORY Version 2.4		  01 Oct 2006			 Z80-MEMORY(3)