PC9821 BIOS - Operating Environment Settings

NEC PC-9821 BIOS Translation

Changing settings in the BIOS of a japanese computer can be dangerous if you don’t have any knowledge of the japanese language or don’t what you’re doing. I don’t have that much knowledge of the language either and tried to translate the BIOS.

This is how I did it: I connected my PC-9821Xe10 with a sync combiner to the Framemeister and grabbed a video of the selection of each and every BIOS menu item. Then I converted the frames of the video to image files. The images were then cropped and converted into grayscale negatives to be processed by an OCR engine. Most of the output was gibberish and every single line of text needed manual processing. The japanese text was then fed into the Bing and Google translators and some common sense added to the output.

Hold down the HELP key when switching on the computer to enter the BIOS.

PC9821 BIOS - Operating Environment Settings
PC9821 BIOS – Operating Environment Settings

System Setup Menu – Main Menu
1. Operating Environment Settings

Information:
16MB Memory Hole
ROM BASIC
Speaker Volume

Hint: Configure the operating environment displayed in the information.

Keys: Up/Down: Select | Return: Decide | HOME CLR: Factory Settings | ESC: Menu End

PC9821 BIOS - 16MB Memory Hole
PC9821 BIOS – 16MB Memory Hole

16MB Memory Hole – Disabled | Enabled

Hints:
When using Windows 3.1 please set it to “enabled”.
1. The system does not use memory hole at 15M-16M.
2. The system uses the memory hole at 15M-16M.

Keys: Up/Down: Select | Left/Right: Set | HOME CLR: Factory Settings | ESC: Back to Main Menu

PC9821 BIOS - ROM BASIC
PC9821 BIOS – ROM BASIC

ROM BASIC – Disabled | Enabled

Hints:
1. Do not start ROM BASIC.
2. Start ROM BASIC.

PC9821 BIOS - Speaker Volume
PC9821 BIOS – Speaker Volume

Speaker Volume – High | Medium | Low | Off

Hint: Set the volume of the internal buzzer.

PC9821 BIOS - End
PC9821 BIOS – End

End

Hint: Exit the operation environment settings.

PC9821 BIOS - DIP Switch 1 Settings
PC9821 BIOS – DIP Switch 1 Settings

2. DIP Switch 1 Settings

Information:
Plasma Display
Floppy Disk Sequence
RS-232C Transmission Mode
Hard Disk Sector Size
Graphics Mode

DIP Switch Image

PC9821 BIOS - Plasma Display
PC9821 BIOS – Plasma Display

Plasma Display – Enabled | Disabled

Hint: Usually “disabled”.

PC9821 BIOS - Floppy Disk Sequence
PC9821 BIOS – Floppy Disk Sequence

Floppy Disk Sequence – Internal #3, #4, external #1, #2 | Internal #1, #2, external #3, #4

Hints:
1. Prioritize external Floppy Disk Drives.
2. Prioritize internal Floppy Disk Drives.

PC9821 BIOS - RS-232C Transmission Mode
PC9821 BIOS – RS-232C Transmission Mode

RS-232C Transmission Mode – BCI Sync | ST2 Sync | Sync Clock | Asynchronous

Hints:
1. Use internal clock for transmission, use modem clock for reception.
2. Use modem clock for transmission and reception.
3. Use clock signal created from received data for reception, use internal clock for transmission.
4. Use internal clock for transmission and reception.

PC9821 BIOS - Hard Disk Sector Size
PC9821 BIOS – Hard Disk Sector Size

Hard Disk Sector Size – 512 bytes | 256 bytes

Hints:
1. Set the sector size of the internal hard disk to 512 bytes.
2. Set the sector size of the internal hard disk to 256 bytes.

PC9821 BIOS - Graphics Mode
PC9821 BIOS – Graphics Mode

Graphics Mode – Enhanced | Standard

Hints:
1. Enhanced graphics mode, 16 out of 4096 colors.
2. Standard graphics mode, 8 out of 8 colors.

PC9821 BIOS - End
PC9821 BIOS – End

End

Hint: Exit the DIP Switch 1 settings.

PC9821 BIOS - DIP Switch 2 Settings
PC9821 BIOS – DIP Switch 2 Settings

3. DIP Switch 2 Settings

Information:
Terminal Mode Specification
Lines of Text per Screen
Memory Switch
Internal Hard Disk
GDC Clock

PC9821 BIOS - Terminal Mode Specification
PC9821 BIOS – Terminal Mode Specification

Terminal Mode Specification – Terminal Mode | BASIC Mode
Hints:

1. Start BASIC in terminal mode.
2. Start BASIC in BASIC mode.

PC9821 BIOS - Lines of Text per Screen
PC9821 BIOS – Lines of Text per Screen

Lines of Text per Screen – 25 lines/screen | 20 lines/screen

Hints:
1. Display 25 lines of text per screen.
2. Display 20 lines of text per screen.

PC9821 BIOS - Memory Switch
PC9821 BIOS – Memory Switch

Memory Switch – Keep | Initialize

Hints:
1. Keep the contents of the memory switch at startup.
2. Initialize the contents of the memory switch at startup.

PC9821 BIOS - Internal Hard Disk
PC9821 BIOS – Internal Hard Disk

Internal Hard Disk – Disabled | Enabled

Hints:
1. Disable internal hard disk
2. Enable internal hard disk.

PC9821 BIOS - GDC Clock
PC9821 BIOS – GDC Clock

GDC Clock – 5MHz | 2.5MHz

Hints:
1. Operate GDC with 5MHz clock.
2. Operate GDC with 2.5MHz clock.

PC9821 BIOS - End
PC9821 BIOS – End

End

Hint: Exit the DIP Switch 2 settings.

PC9821 BIOS - DIP Switch 3 Settings
PC9821 BIOS – DIP Switch 3 Settings

4. DIP Switch 3 Settings

Information:
Floppy Disk Mode
Floppy Motor Control
DMA Clock
Internal RAM Hole
CPU Mode

PC9821 BIOS - Floppy Disk Mode
PC9821 BIOS – Floppy Disk Mode

Floppy Disk Mode – 640K | 1M | Automatic (640K) | Automatic (1M)

Hints:
1. Use internal floppy disk drive with 640Kbyte fixed.
2. Use internal floppy disk drive with 1Mbyte fixed.
3. Automatic recognition of 640Kbyte/1Mbyte. Use 640Kbyte when starting with another device.
4. Automatic recognition of 640Kbyte/1Mbyte. Use 1Mbyte when starting with another device.

PC9821 BIOS - Floppy Motor Control
PC9821 BIOS – Floppy Motor Control

Floppy Motor Control – Disable | Enable

Hints:
1. Do not control floppy disk motor.
2. Stop floppy disk motor if no access for 15 seconds.

PC9821 BIOS - DMA Clock
PC9821 BIOS – DMA Clock

DMA Clock – High-Speed | Compatible

Hints:
1. Operate DMA with high-speed clock.
2. Operate DMA with compatible clock.

PC9821 BIOS - Internal RAM Hole
PC9821 BIOS – Internal RAM Hole

Internal RAM Hole – Disabled | Enabled

Hints:
1. Disable memory hole at 512K-640Kbytes.
2. Enable memory hole at 512K-640Kbytes.

PC9821 BIOS - CPU Mode
PC9821 BIOS – CPU Mode

CPU Mode – High | Low

Hints:
1. Start in High mode.
2. Start in Low mode.

PC9821 BIOS - End
PC9821 BIOS – End

End

Hint: Exit the DIP Switch 3 settings.

PC9821 BIOS - Power Saving Settings
PC9821 BIOS – Power Saving Settings

5. Power Saving Settings

Information:
Internal Hard Disk Control

Hint: Configure the power saving settings displayed in the information.

PC9821 BIOS - Internal Hard Disk Control
PC9821 BIOS – Internal Hard Disk Control

Internal Hard Disk Control – Enable (15 Minutes) | Disable

Hints:
1. Stop the hard disk motor when there is no access within the set time.
The time can be set from minimum 15 minutes up to 60 minutes.
Set the time with the [ROLL UP] and [ROLL DOWN] keys.
2. Do not control the motor of the internal hard disk.

PC9821 BIOS - End
PC9821 BIOS – End

End

Hint: Exit the power saving settings.

PC9821 BIOS - I/O Device Settings
PC9821 BIOS – I/O Device Settings

6. I/O Device Settings

Information:
Window Accelerator Configuration
Disk Interface Unit

Hint: Configure the input/output devices displayed in the information.

PC9821 BIOS - Window Accelerator Configuration
PC9821 BIOS – Window Accelerator Configuration

Window Accelerator Configuration – F00 | F20 | F40 | F60

Hints:
This setting is available only for machines with installed Window Accelerator.
1. The standard memory for Window Accelerator is allocated to addresses F00000H-F0FFFFH and F80000H-F80FFFH.
2. The standard memory for Window Accelerator is allocated to addresses F20000H-F2FFFFH and F88000H-F88FFFH.
3. The standard memory for Window Accelerator is allocated to addresses F40000H-F4FFFFH and F90000H-F90FFFH.
4. The standard memory for Window Accelerator is allocated to addresses F60000H-F6FFFFH and F98000H-F98FFFH.

PC9821 BIOS - Disk Interface Unit
PC9821 BIOS – Disk Interface Unit

Disk Interface Unit – Disabled | Enabled

Hints:
1. PC-9801RA-35/34, PC-9801DA-35 not connected.
2. PC-9801RA-35/34, PC-9801DA-35 connected.

PC9821 BIOS - End
PC9821 BIOS – End

End

Hint: Exit the I/O device settings.

PC9821 BIOS - End
PC9821 BIOS – End

7. End

Hint: Exit the System Setup Menu.

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