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Using the K & P 64K-RAM Card 
MZ800 Basic

There are 47kb RAM free of 64kb if using this card. For programming information like command syntax refer to the Basic Manual. The K & P 64K-RAM card is similar to the Sharp RAM card MZ-1R18.


The Sharp P-CPM is fully supported. The drive number is "E" and you can use a maximum of 63kb.

Machine Language

The card uses two I/O addresses: $EB and $EA. $EB is used to address the 64k RAM. $EA is the data port. The address is automatically incremented by each access to the data port. This gives an efficient RAM access by using the Z80 commands.

Register B must be loaded by the MSB. Examples:

Writing the value $56 to $EF07:

LD   A,07   ;LSB
LD C,EB ;port EB
OUT (C),A ;output EF07
LD A,56
OUT (EA),A ;output data value 56

Read data from $D8C2:

LD   A,C2   ;LSB
LD C,EB ;port EB
OUT (C),A ;output D8C2
IN A,(EA) ;read data

IN A,(EA) must follow now to read the following data byte.

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last updated December 29, 2003