12. read/write from the z-80 to v ram, Mz3500 – Sharp MZ-3500 User Manual
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MZ3500
4-12. Read/write from the Z-80 to V RAM
Read/write of the Model 3500 V-RAM is done via the
UPD7220GDC. There are two methods used to read/write
data. The method (1) is used for the model 3500.
(1) Read/write via the 16 byte FIFO.
(2) Read/write of V-RAM in the DMA mode without
intervention of the FIFO.
¡Outline of the read/write data via the FIFO;
Set parameter for the command
Set parameter for the command.
I
\
Method used to give a command
to the GDC.
y
Command must be given to the GDC in the same manner.
On next page is the program of the above flowchart.
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