Sharp MZ-800 - Appendix F Monitor Subroutines

Appendix F Monitor Subroutines
The following subroutines are used by the ROM Monitor (9Z-504M). Each subroutine name symboli-
cally represents the function of the corresponding subroutine. These subroutines can be called from
user programs.
Registers saved are those whose contents are restored when control is returned to the calling program.
The contents of other registers are changed by execution of the subroutine.
Name and entry point (hex.) Function Registers saved
CALL LETNL Moves the cursor to the beginning of the next line. All except AF
(0006)
CALL PRNTS Displays a space at the cursor position. All except AF
(000C) ||
CALL PRNTS Displays the character corresponding to the ASCII code All except AF
(0012) stored in the ACC at the cursor position. See Appendix J
for the ASCII codes. No character is displayed when code
OD (carriage return) or codes 11 to 16 (the cursor control
codes) are entered, but the corresponding function is still
performed (a carriage return for 0D and cursor movement
for 11 to 16).
CALL MSG Displays a message, starting at the position of the cursor. All registers
(0015) The starting address of the area in which the message is
stored must be loaded into the DE register before calling
this subroutine, and the message must end with a carriage
return code (OD).
The carriage return is not executed.
The cursor is moved if any cursor control codes (11 to 16)
are included in the message.
CALL BELL Briefly sounds tone of la (about 880 Hz). All except AF
(003E)
CALL MELDY Plays a tune according to the music data stored in the All except AF
(0030) memory area starting at the address in the DE register.
The music data must be in the same format as that for the
MUSIC statement of the BASIC, and must end with 0D or
cs.
When the tune is completed, control is returned to the call-
ing program with the C flag set to 0. When play is inter-
rupted with the key. Control is returned with the
C flag set to 1.
CALL XTEMP Sets the music tempo according to the tempo data stored All registers
(0041) in the accumulator (ACC).
ACC + O1 Slowest speed
ACC + 04 — Middle speed
ACC + 07 Highest speed
Note that the data in the accumulator is not the ASCII
codes for | to 7 but the binary codes.
CALL MSTA Generates a continuous sound of the specified frequency. BC and DE
(0044) The frequency is given by the following equation
freq. = 895 kHz/nn’.
Here, nn’ is a 2-byte number stored in addresses 11A1 and
11A2 (n in 11A2 and n’ in 11A1) =!