Yamaha Mio, Руководство по обслуживанию

Страница: 60 / 73

Table 5-1. MIO Register Selection
Register Operation
Address
(HEX)
Write Read
$D1E0
Set address A15-A8 for $D600 RAM
window. (LSB of sector number.) Set RST- signal true (low). Resets the
SCSI/SASI bus. (RST- also true during
RESET)
$D1E1
Set printer data and SCSI/SASI data. True
logic for printer — Inverted for SCSI/SASI
bus. Read data from SCSI/SASI bus. Data is
inverted.
$D1E2
General purpose outputs.
B[3..0] High RAM address,
sets address A19-A16.
B[4] 1 = Set SEL- true
B[5] 1 = Enable RAM access
B[6] 1 = Set STROBE- true
B[7] 1 = Enable Parallel IRQ
General purpose inputs.
B[0] = SASI C/D-
B[1] = SASI MSG-
B[2] = SASI I/O-
B[4] = Printer FAULT-
B[5] = SASI BUSY-
B[6] = Printer BUSY
B[7] = SASI REQ-
Also clears RST- signal
$D1E3
or
$D1FF
Set ROM enable and bank. Only
1 bit allowed set at a time.
B[2] 1 = Disk Interface ROM
B[3] 1 = Seg 2 of setup MENU
B[4] 1 = R:/P: Handler ROM
B[5] 1 = Seg 1 of setup MENU
All bits 0 disable the ROM. IRQ sense bits + Misc inputs.
B[0] = RS-232 DCD line
B[1] = RS-232 DSR line
B[2] = RS-232 CTS line
B[3] = Printer BUSY- IRQ
B[4] = MIO IRQ (from 6551 or
Printer BUSY- IRQ)
$D1C0 Write ACIA transmit register. Read ACIA receive register.
$D1C1
Perform a programmed RESET on ACIA
(data is "don't care"). Read Status register (resets IRQ).
B[0] 1 = Parity error
B[1] 1 = Framing error
B[2] 1 = Overrun has occurred
B[3] 1 = Receiver reg. full
B[4] 1 = Transmitter empty
B[7] 1 = IRQ occurred
$D1C2
Write ACIA command register.
(see table 5-2) Read ACIA command register.
(see table 5-2)
$D1C3
Write ACIA control register.
(see table 5-3) Read ACIA control register.
(see table 5-3)
$D6xx
Write RAM. High address A19-A8 selected
by $D1E0/$D1E2. Read RAM. High address A19-A8
selected by $D1E0/D1E2.
MIO Service Manual Page 59