HA-55BS4, HA-55BSW (Nippon Teksa)

Multi-vendor compatible C bus bus master SCSI board by parameter setting.
Although not compatible with Windows 95 (Japan Teksa has withdrawn from the PC-98 peripheral market before Windows 95 is released),
When using it, set the transfer mode to W-GT mode or DMA transfer and let the 55 board driver recognize it.
Reference http://web.archive.org/web/20010430164823/http://www.texa.co.jp:80/TEXA/
　　　oshiete / answer / Windows.html
* In TEXA, bus master transfer is expressed as bus steal transfer (HS-BS mode), and I / O transfer (CPU transfer, PIO transfer)
Is sometimes referred to as W-GT mode.
The transfer method is automatically selected by CPU and HDD discrimination.
HS-BS mode is not available on V30 machines and PC-H98 series (automatically becomes W-GT mode).
In addition, HS-BS mode is not possible even when the memory of 16 MB or more is installed in the PC body (W-GT mode or DMA mode)
Use in).
Please use the following expansion slots for the following models:
PC-9801VX0, 2, 4 ...... # 2, # 3, # 4
PC-98 XA ...... # 3, # 5
PC-286LS (T), PC-386LS (C / X) / LSR ...... # 2 (left side seen from the back)
Also, set the DMA channel to 0 when using the following expansion slots with the following models:
PC-9801 / VM0. 2, 4 ...... # 4
PC-9801UF / CV ...... # 2
PC-286U ...... # 2
Also, on the following models, attach the switch pin beside the card edge connector in reverse:
PC-9801UV / CV / UR / UF
* There is a case that the PC-9801UV2 does not operate due to the signal disturbance of the expansion slot.
Also, with PC-9801DS, there may be cases where it does not operate normally, such as initialization can not be performed in HS-BS mode.
Board settings are based on the "Switch Setting Utility".There are BIOS version and FD version in this,
The former is activated by pressing and holding [T] + [S] simultaneously when the main unit starts.
【note】
・ Since there is a system selector in high resolution mode, when using the FD version switch setting utility,
Start while holding down the CTRL key, check the beeper of the selector and then release the key.
-If the settings are incorrect and the BIOS version or FD version switch setting utility can not be started,
By activating the main unit while pressing the red “setting reset switch” on the back of the board
You can start the FD version switch setting utility.
• If the I / O port address is set to other than the initial setting [CC0H-CC4H (CC6H, CC7H)],
The BIOS_ROM is automatically set to disabled.
In this case, the BIOS version switch setting utility can not be started
("CC6H, CC7H" in parentheses are used additionally in W-GT mode (I / O transfer)).
・ When W-GT mode (I / O transfer) is selected or when used with PC-H98 series, with PC-9801-29 (GP-IP) etc.
In such a case, set the transfer mode to DMA because there are conflicting I / O addresses.
・ “Hold request channel” is a bus used during bus steal (bus master) operation
Hold channel.
・ About "D-Quick" function of "Optional Settings":
Search SCSI_ID of connected SCSI devices and automatically store them on the board.
As a result, since the SCSI_ID search of the connected SCSI device is performed, the boot time can be shortened.
Once the SCSI_ID is stored, the storage of the SCSI_ID is retained even if the power of the main unit is turned off.
When adding or removing a SCSI device while the D-Quick function is enabled,
When activated while simultaneously pressing [T] + [D] (not [T] + [S]),
A search for SCSI_ID is performed and the board is stored again.
・ About "WAIT timer":
It is possible to delay the start of ID search for SCSI devices with slow start-up.
You can cancel WAIT by pressing the ESC key during WAIT.It is valid only when the power is turned on and invalid when it is reset.
・ About "Reset WAIT":
SCSI reset can be delayed from the time of main unit startup.Valid only when the power is on.
・ About "Device recognition":
The ID of the connected SCSI device can be registered in advance and stored.
By this, it is possible to omit the check of the ID that is not connected at the time of main unit startup, and to shorten the startup time.
When adding a SCSI device, be sure to specify the ID of the additional device.
・ About "Initialization Protect":
Do not accidentally initialize the HDD.If this function is enabled, it will be against the execution of format.exe of MS-DOS,
Display the message "initialization failed" and exit without initialization.
・ About "Read Protect":
If an HDD that can not be accessed due to destruction of the system area or unauthorized access is connected,
In some cases, FDD boot for initialization can not be performed.
In such a case, FDD activation is enabled by prohibiting the HDD from being booted.
After startup, press the STOP key to release the boot prohibition and then execute the format command.
・ About "Device transfer method":
Data transfer method can be set for each SCSI_ID.Valid only when using MS-DOS.
・ About "Device parameter":
Various parameter modes can be set for each SCSI_ID.When using TEXA HDD, use only TEXA parameters.
※ MO HD image (Large) ...... Recognizes 3.5 inch MO as about 127 MB HDD
　MO HD image (Small) ...... Recognizes 3.5-inch MO as an approximately 121 MB HDD
　Other mode ...... It becomes PC-OD301 compatible mode of NEC and recognizes as 3.5 inches MO

・ About "P-Quick Function" of "Other functions":
It simplifies MS-DOS initialization and reduces initialization time.
P-Quick enabled with kana key OFF and disabled with ON when format.exe is launched.Valid only when using MS-DOS.
When changing the sector length,
When re-initializing an HDD that has been reset / power off during initialization, release P-Quick and perform initialization.
・ About "L-Quick Function":
Simplify the area reservation of MS-DOS and shorten the area reservation time.
L-Quick enabled with CAPS key OFF when format.exe is launched, disabled with ON.Valid only when using MS-DOS.
・ About "SCSI_ID search stop function":
The search for SCSI_ID can be stopped while pressing the GRAPH key when the search screen is displayed.
・ About "SCSI_ID search stop function":
You can cancel the SCSI_ID search by pressing the CTRL key when the search screen is displayed.

[About the startup screen]
-"Device =": Type of recognized SCSI device
HD5: HDD with a sector length of 512 bytes / sector
HD2: HDD with a sector length of 256 bytes / sector
HD ...... HDD with unknown sector length
MO3: NEC PC-OD 301 compatible mode for 3.5 inch MO disk
MO5 ...... NEC PC-OD101
mhd ...... Hard disk image mode of removable device
CD ...... CD-ROM drive
otr ... SCSI device recognized other than above
un ...... A SCSI device that has been recognized but disconnected because it can not operate
(Eg if media is not inserted within mhd wait time)
Blank ... No response from the specified ID number (not connected)
[Recognition confirmation message]
?...... Checking recognition
wait ... waiting because the SCSI device is in "busy" status
media ... request media when no media is inserted at hmd
-"Hd pmt": SCSI_HDD parameter mode
txa ... TEXA parameter
nec ... NEC parameter (92 parameters)
ntl ... NATURAL parameter (parameter that SCSI_HDD originally has)
mnl ... Manual parameter (Manual setting of HDD head number / sector number / cylinder number manually)
-"Id trs": Transfer method
bs ...... HS-BS method
gt ...... W-GT method
dma ...... DMA method
・ Message area:
syc: SCSI synchronous transfer of target ID is possible
waiting .... xx ...... Displayed during WAIT when the WAIT timer function is enabled, xx is the count number until the end
Non Device ... When no SCSI device is recognized
-"DMA / INT =": DMA channel / interrupt (INT) level
・ "Loc =": ROM address location
・ "Port =": I / O port address
-"Transfer =": data transfer method
・ Others: The following message is displayed at the time of abnormality by self-diagnosis at startup
Error ROM sum ...... The content of SCSI BIOS is abnormal
Error DMA or INT setting ...... Incorrect setting of DMA channel and INT level

※ About automatic loading of parameters:
It does not operate with anything other than PC-9801-55 fully compatible SCSI_I / F.
Connect the I / F used so far and the target HDD and start the switch setting utility,
Select target HDD and record parameters in setting utility.
Next, replace the I / F with this product, connect the target HDD, and start the switch setting utility,
Select the target HDD ID and register the parameters to this product.
If there are multiple target HDDs, repeat these operations.

※ When HA55BSW transfers a large amount of data, 1 byte of data drop occurs every 64 KB
The following bug has been reported.This is not only the bus steal transfer mode but also W-GT mode
But it is said to happen.On the other hand, there are also reports that this phenomenon could not be confirmed.