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→1-2 Design Concept
==1-1 Program Configuration==
==1-2 Design Concept==
The MBIOS was designed with the following main concepts in mind.
First, MBIOS users should not have to worry directly about the
hardware. The controls of the built-in FM sound chip, and that of
midi interface, are all carried out by the MBIOS, freeing the user
from this task.
Second, the concept of a virtual instrument should be defined in
the user's program space. By instrument, we mean the processing
system for real-time key-on/key-off requests (events).
MBIOS defines the instrument by using an IDB(Instrument
Definition Block) that is linked to the built-in FM sound generator
IC or MIDI interface as the actual instrumental outputs.
Thus (considering event data being input to the instrument), once
the instrument is defined, the user can control the FM sound
generator IC by manipulating only the event data.
Third, the slot management of the MSX system should be left up
to user. This enables a multiple number of slots to be used
together with the M-BIOS. In other words, the M-B1OS does not
address the slots by itself (with some exceptions). This enables the
user to call out the IRQ processing module of the MBIOS by
switching the slot to SFG-0 I , even when the interrupt is received
at the user's slot.
Fourth, there may be parallel prcessing by service calls.
That is, the processes of Keyboard Scanning and Instrument
Performance (PLAY), as well as the real-time processes such as
event buffer handling for automatic reformance, can run
simultaneously by appropriately issuing MBIOS calls in the user's
main program or in his interrupt routines.
==1-3 Hardware Configuration==
==1-4 Interface with MSX BASIC==
