Copyright(C) 1994,1995,1996,1997 Terumasa KODAKA , Takeshi KONO
■FC-9800 series exclusive functions
Target FC-9801-06 first generation/K, FC-9800 series built-in type
Explanation o The FC-9800 series uses special I/O ports for RAS functions and RAM files.
I/O 7FD0h
Name RAS function
Target FC-9801-06 first generation/K, FC-9800 series built-in type
Function
[WRITE]
bit 7～0: RAS command
01h: Initialize the RAS board
02h: Stop watchdog timer
03h: Reset and start watchdog timer
04h: Turn off the interrupt enable F/F of interrupt group 1 (disable interrupts)
05h: Turn on interrupt enable F/F for interrupt group 1 (enable interrupts)
06h: Turn off the interrupt enable F/F of interrupt group 2 (disable interrupts)
07h: Turn on the interrupt enable F/F of interrupt group 2 (enable interrupts)
08h: Use prohibited
09h: Reset interrupt source for interrupt group 2
0Ah: Set status 1 (alarm input) to read mode
0Bh: Set status 2 (mask F/F, watchdog timer) to read mode
0Ch: Set status 3 (digital input/output) to read mode
0Dh: Set status 4 (watchdog timer set value H) to read mode
0Eh: Set status 5 (watchdog timer set value L) to read mode
0Fh: Set status 6 (interrupt level value) to read mode
1nh: Digital output (DO)
bit 7～4: 0001b
bit 3: OUT4 ch4 digital output
bit 2: OUT3 ch3 digital output
bit 1: OUT2 ch2 digital output
bit 0: OUT1 ch1 digital output
1=output
0=no output
20h: Turn off digital input (DI) interrupt enable F/F (disable interrupts)
21h: Turn on digital input (DI) interrupt enable F/F (enable interrupts)
22~2Fh: Prohibited to use
3n~6nh: Watchdog timer value set
bit 7~4: 0011b
bit 3～0: X1
bit 7～4: 0100b
bit 3～0: X2
bit 7~4: 0101b
bit 3～0: X3
bit 7～4: 0110b
bit 3～0: X4
7nh: Interrupt level set for interrupt group 2
bit 7～4: 0111b
bit 3~0: 0xxxb= No interrupt occurs
1000b=INT0
1001b=INT1
1010b=INT2
1011b=INT3
1100b=Do not use
1101b=INT5
1110b=INT6
1111b=NMI
80~FFh: Prohibited to use
[READ] Read RAS status
- Status 1 (alarm input)
bit 7: DIA (digital input)
* Becomes "1" when any bit of DI ch1 to ch4 changes to 1 and both IM2 and DIM (see status 2) are enabled.
bit 6: FA (fan alarm)
bit 5: OA2 (external alarm 2)
bit 4: OA1 (external alarm 1)
bit 3: TA (temperature rise alarm)
bit 2: WA (watchdog timer alarm)
bit 1: MA (memory parity alarm)
bit 0: PA (power off alarm)
1=occurrence
0=normal
- Status 2 (mask F/F, watchdog timer)
bit 7~4: 0
bit 3: DIM (digital input interrupt enable F/F)
bit 2: IM2 (Interrupt group 2 enable F/F)
bit 1: IM1 (Interrupt group 1 enable F/F)
1=enable
0=disabled
bit 0: WRN (watchdog timer operating status)
1=running
0=stopped
- Status 3 (digital input/output)
bit 7: OUT4 (ch4 digital output)
bit 6: OUT3 (ch3 digital output)
bit 5: OUT2 (ch2 digital output)
bit 4: OUT1 (ch1 digital output)
bit 3: IN4 (ch4 digital input)
bit 2: IN3 (ch3 digital input)
bit 1: IN2 (ch2 digital input)
bit 0: IN1 (ch1 digital input)
1=OFF
0=ON
- Status 4 (watchdog timer set value H)
bit 7～4: X1
bit 3～0: X2
- Status 5 (watchdog timer set value L)
bit 7～4: X3
bit 3～0: X4
- Status 6 (interrupt level value)
bit 7: NMI
bit 6: INT6
bit 5: INT5
bit 4: ---
bit 3: INT3
bit 2: INT2
bit 1: INT1
bit 0: INT0
Bit set is 1
Description o I/O for RAS board and built-in RAS function.
o The I/O address can be changed using the rotary switch on the interface board.
I/O 7DD0h,7EE0h
Name RAM file
Target FC-9801F-RF1･2, FC-9801S-RF1･2
Function
------------+-------+-----+-----------------------------------------------
I/O address | width | R/W | content
------------+-------+-----+-----------------------------------------------
7DD0h | BYTE | R | Status 1
| | | bit 7: WP2 (RAM file #2 write protection)
| | | bit 6: WP1 (RAM file #1 write protection)
| | | 1=enabled
| | | 0=disabled
| | | bit 5～2: S5～S8(A16～13)
| | | * RAM file address switch
| | | (DIP SW status on board)
| | | bit 1: PE (memory parity error)
| | | 1=normal
| | | 0=error detection
| | | bit 0: 0 (unused)
7DD0h | BYTE | W | Bank switching
| | | Bank number (00~9Fh)
------------+-------+-----+-----------------------------------------------
7ED0h | BYTE | R | Status 2
| | | bit 7,6: unused
| | | bit 5: RF2 (RAM file #2 selection)
| | | bit 4: RF1 (RAM file #1 selection)
| | | 1=enabled
| | | 0=disabled
| | | bit 3～0: 0 (unused)
7ED0h | BYTE | W | RAM file selection
| | | bit 7: 1(RAM file selection)
| | | bit 6~2: unused
| | | bit 1,0: 10b= RAM file #2 selection
| | | 01b= RAM file #1 selection
7ED0h | BYTE | W | Parity & Bank Reset
| | | bit 7: 0 (Parity & Bank Reset)
| | | bit 6～0: unused
| | | Memory error, bank specification, RAM file selection reset
------------+-------+-----+-----------------------------------------------
Description o I/O for controlling nonvolatile RAM disks (RAM files) that can be used with floppy disk images.