IF-92B (TEAC)

Multi-vendor non-compliant C bus bus master SCSI board.

In the following main unit, I / O strings mode (CPU transfer is automatically done by setting the bus master mode)
Switch to mode, PIO transfer mode):
　PC-9801VM / UV / CV / UF / UR, PC-H98 all models, PC-H98S all models, PC-286U
In addition, although the forced DMA mode is for a machine equipped with the 8086, the TEAC PC system is in use
Please contact support center (support has already ended).
Also, IF-92B can not be used in the following main body:
　PC-98DO / DO + / GS, PC-286C
In PC-9801VM / CV / UV, there are models with different usage of DMA channel,
Such lots may not work properly with the manual settings.
I examined the BIOS ROM 1.20 which was examined using e10chk.exe which is free software written by Mr. Marimo.
The upper limit of the recognition capacity of this board was 2015 MB.

・ 8-station dip switch SW1: SCSI_ID of board, interrupt level, DMA channel setting
1-2-3: SCSI_ID
　ON-ON-ON: ID = 7
4-5-6: Interrupt level
　OFF-OFF-OFF: INT0
　ON-OFF-OFF: INT1
　OFF-ON-OFF: INT2
　ON-ON-OFF: INT3
　OFF-OFF-ON: INT5
　ON-OFF-ON: INT6
7-8: DMA channel
　OFF-OFF: DMA0
　OFF-ON: DMA2
　ON-ON: DMA3

・ 8 stations dip switch SW2: BIOS_ROM setting
286/386/486 equipped normal mode machine
　OFF-ON-ON-OFF-ON-ON-ON-ON (DC000H to DCFFFH)
V30 equipped normal mode machine
　OFF-ON-ON-OFF-ON-ON-OFF-ON (DC000H to DCFFFH)
Normal mode / High res mode dual machine
(Including high resolution board loading machine)
　OFF-ON-ON-OFF-ON-OFF-ON-ON (in normal mode: DC000H to DCFFFH)
　　　　　　　　　　　　　 　(In high resolution mode: EC000H to ECFFFH)
High res mode dedicated machine (PC-98XA)
　OFF-ON-ON-OFF-ON-OFF-OFF-ON (EC000H to ECFFFH)

When simultaneously implementing the BRANCH 4670 II interface (PC-9864L),
Turn on 4, 5 regardless of the main unit model.
In addition, it is not possible to use with the GP-IB board because the ROM addresses conflict.

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ASCII book section, PC-98 series peripheral equipment super tune-up (1994 issue)
According to, the meaning of SW2 seems to be:

・ 8 stations dip switch SW2: Local memory address, setting of main unit model
1-2-3: Local memory address (normal) setting
　OFF-OFF-OFF: D0000h to D0FFFh
　ON-OFF-OFF: D2000h to D2FFFh
　OFF-ON-OFF: D4000h to D4FFFh
　ON-ON-OFF: D6000h to D6FFFh
　OFF-OFF-ON: D 8000 h to D 8 FFF h
　ON-OFF-ON: DA000h to DAFFFh
　OFF-ON-ON: DC000h to DCFFFh (factory setting)
　ON-ON-ON: DE 000 h to DEFFF h
4-5: Setting of local memory address (high res)
　OFF-OFF: E8000h to E8FFFh
　ON-OFF: EA000h to EAFFFh
　OFF-ON: EC000h to ECFFFh (factory setting)
　ON-ON: EE000h to EEFFFh
6-7: Setting of machine model
　OFF-OFF: PC-98XA
  ON-OFF: CPU is the model of 8086 / V30
　OFF-ON: Normal / High res combined machine
　ON-ON: CPU model 286/386/486 (default setting)
8: Do not change (factory setting ON)
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・ 8-station dip switch SW3: I / O port address, data transfer method, ID search
Show / Hide, boot mode settings
1-2: I / O port address
　OFF-OFF: CCXH (X = 0, 2, 4)
　ON-OFF: CDXH
　OFF-ON: CEXH
　ON-ON: CFXH
3: Transfer mode
　ON: Bus master mode
　OFF: Forced DMA mode
　In the main body equipped with 16 MB or more of memory, the setting of forced DMA mode.
4: Presence or absence of ID display at boot
　ON: ID display
　OFF: ID hidden
5: Boot mode
　ON: High-speed boot mode (shortens the time required for system startup from HDD)
　OFF: Standard boot mode
　If the HDD can not be recognized in the fast boot mode, set it to the standard boot mode.
　When restarting the system by pressing the reset switch on the main unit, either high speed or standard
　Even in the mode, you can boot faster by holding down the [GRAPH] key while checking the memory.
　However, the power of the HDD should be turned on at least 20 seconds before the reset.
6-7-8: No change

・ 4 series jumper switch JB1: DMA control signal priority setting (no change)
Always 3-6, 4-5 short, 1-8, 2-7 open

・ SW pin: Switch pin on the side of the card edge.Specification of body model
In PC-9801U2 / UV2 / UV21 / UV11 / CV21 / UR / UF, the SW pin is reversed (the protrusion is facing the back of the board)
Change to).For other models, make sure that the pin faces the C bus connector.


About the fast format mode:
MS-DOS FORMAT command with both the [CAPS] and [Kana] keys on the keyboard turned on
The time required for processing can be shortened by initializing the HDD or securing the area using.
In high-speed format mode, inspection at initialization and area allocation is skipped.Therefore
The high-speed format mode is used when initializing and securing the area as recovery means of HDD
Can not.