IF-2769 (ICM)

PnP and multi-vendor compatible C bus bus master SCSI I / F. More than 16MB of memory
Bus master transfer is possible even on the main unit.Last C bus SCSI I / F (product after the release of Windows 95) before ICM bankruptcy
The final revision of the BIOS ROM is 1.03.Revision 1.02 or earlier from 1GB or more
It is said that startup is not possible, but I use e10chk.exe which is free software created by Mr. Marimo
When the upper limit of recognition capacity of this board was checked, BIOS ROM is not compatible with 8GB at 1.01
(There is a wall of 1GB?), 1.02 and 1.03 result that 8GB correspondence was obtained.
It is famous for being the fastest SCSI board with C bus as well as green electronic MDC-926Rs.Even as a serious runaway horse
It is known that it works stably if it is known, but even if it is an officially compatible model,
Operation is not stable / does not work properly / causes FAT or file corruption
There are a lot of things.Although these are often reported in bus master transfer mode, FIFO transfer mode
There is also a report on (There are many trouble reports of this I / F in the past log etc.).
When installing the miniport driver of this I / F in Windows 95 which is not OSR2, this I / F is once PC-9801-55
It is necessary to change the driver to that of IF-2769 after updating as a driver update.
There is one quadruple dip switch on the board.

Interrupt level, DMA channel, transfer mode, reset wait time, SCSI-ID, quick
Format and disk parameter settings are [CTRL] + [S] at startup / reset.
Set on the setting menu screen that is displayed when the key is held down.
Quick format and disk parameters can be set for each connected HDD.
While writing the value set in the setting menu screen to the non-volatile memory on the I / F,
The message "Recording settings" is displayed, but while this is displayed, it is absolutely
Do not turn off the main unit or reset the main unit.

If the disk parameter is set to "ANL", the HDD parameter
Automatic analysis is performed.To manually start the HDD parameter analysis program:
Hold down the [CTRL] + [A] key while starting / resetting the main unit.

・ 4 stations dip switch SW1: PnP, BIOS ROM, setting of normal / default mode
1: Setting of PnP
　ON: PnP disabled
　OFF: PnP enabled (factory setting)
2: BIOS ROM setting
　ON: BIOS ROM used (default setting)
　OFF: BIOS ROM not used
3: Switching between fixed mode and normal mode
　ON: Default mode (*)
　OFF: Normal mode (factory setting)
4: Not used (Factory setting: OFF)
* Memory base address = DC000h, I / O base address = CC0h,
Interrupt level = INT 0 (IRQ 3), DMA channel = 3, transfer method = DMA transfer
Works with settings.This setting is for emergency use, and this I / F is used for reasons such as BIOS ROM data corruption.
It is for checking whether it works by turning it on when it does not work.

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【The following is common to IF-2767 / 2768/2769】
Valuestar for PC-9821V7 or later, mate-X for PC-9821Xa7e / Xb10 or later, PC-9821Cb3
Since the specification of C bus has been changed in CanBe later, IF-2767 / 2768/2769
C bus memory refresh of PC when using in bus master mode
It is necessary to output a signal.The C bus memory refresh signal is
Send when holding down [ESC] + [HELP] + [5] at startup of the machine,
Stop by holding down [ESC] + [HELP] + [6] while starting up the machine
It is done.Problems when C bus memory refresh signal is sent (turned on)
And the measures are as follows:
(1) EMM 386.It does not operate normally when EXE is not incorporated
　→ EMM 386 in CONFIG.SYS.Incorporate the EXE.However, EMM 386 attached to MS-DOS made by NEC.EXE
　　Other third-party EMS memory managers are not certified.
(2) It does not operate normally in the safe mode of Windows 95
　→ Stop the C bus memory refresh signal when starting up in the safe mode,
　　Set the data transfer method of this board to FIFO or DMA.
(3) When using DPMI (used by MS-DOS version Ichitaro ver.5 etc.) with MS-DOS ver.5.0 / 5.0A
　 Hang-up
　→ Use MS-DOS ver. 6.2 or higher.DPMI drivers from manufacturers other than NEC
　　Operation is not guaranteed.
* These problems occur regardless of whether or not IF-2767 / 2768/2769 is used.