Electronics > Repair
What more i can do?
amyk:
This appears to be a PC-98 compatible system, based on the boot sector code at the beginning of the ROM image. There's very little detailed technical information in English about them online, as it's a Japanese-native platform. Here's a useful reference I came across trying to figure out why the boot sector was using INT 1B seemingly to read the rest of the ROM disk (use translator): http://radioc.web.fc2.com/column/pc98bas/bios/disk.htm
222Lab_Test222:
--- Quote from: fzabkar on December 16, 2024, 07:16:11 am ---
The FDC37C661 device is a 2.88MB Super I/O Floppy Disk Controller with a parallel port, 2 x serial ports and an IDE interface.
https://theretroweb.com/chip/documentation/fdc37c661-6419cedba3e3f070037826.pdf (datasheet)
--- End quote ---
The Disk here, what is it trying to represent.
I mean is there anything similiar to 100 Pin IC in motherboard. I think nope.
fzabkar:
BIOS structure
--- Code: ---0x0000 - 0x1FFF -- mostly empty, file header
0x2000 - 0x2FFF -- 3mode FD-BIOS KDX4.1.34 for FDC37C661 by WACOM 1997.04 Rev.Sun&Moon
0x3000 - 0x3FFF -- ROM disk XBIOS KDX4.1.30 1995.12 SUN
0x4000 - 0x4FFF -- PCD BIOS Ver2.03 Copyright 1997 WACOM Engineering Co., Ltd.
0x5000 - 0x5FFF --
0x6000 - 0x98FF --
0x9900 - 0xD1FF --
0xD200 - 0xD4FF --
0xD500 - 0xEFFF -- XBIOS 1.00 1995 PCMCIA Socket Service 2.10, Driver Rev 1.01, Copyright WACOM Engineering 1996.01
0xF000 - 0xF7FF --
0xF800 - 0xFFFF -- KDX.1.34A Copyright 1993,¥¥,97 WACOM
--- End code ---
On power-up, the BIOS jumps to 0xF000 in KDX.SYS and begins POST-ing.
I have used DEBUGX to disassemble the code. Offset 0x100 in the listing equates to offset 0xF800 in KDX.SYS.
If a particular test fails, it results in a CPU halt (HLT). There does not appear to be a diagnostic port.
This is the first test:
--- Code: ---0C1E:0119 66C1E210 SHL EDX,10
0C1E:011D B044 MOV AL,44
0C1E:011F E611 OUT 11,AL
0C1E:0121 B092 MOV AL,92
0C1E:0123 E637 OUT 37,AL
0C1E:0125 B00F MOV AL,0F
0C1E:0127 E637 OUT 37,AL
0C1E:0129 B00B MOV AL,0B
0C1E:012B E637 OUT 37,AL
0C1E:012D B000 MOV AL,00
0C1E:012F E65F OUT 5F,AL
0C1E:0131 E652 OUT 52,AL
0C1E:0133 BA7100 MOV DX,0071
0C1E:0136 BB1000 MOV BX,0010
0C1E:0139 B90300 MOV CX,0003
0C1E:013C B4FF MOV AH,FF
0C1E:013E 8AC3 MOV AL,BL
0C1E:0140 E677 OUT 77,AL
0C1E:0142 EB00 JMP 0144
0C1E:0144 8AC4 MOV AL,AH
0C1E:0146 EE OUT DX,AL
0C1E:0147 EB00 JMP 0149
0C1E:0149 8AC7 MOV AL,BH
0C1E:014B E677 OUT 77,AL
0C1E:014D EB00 JMP 014F
0C1E:014F EC IN AL,DX
0C1E:0150 EB00 JMP 0152
0C1E:0152 3AC4 CMP AL,AH
0C1E:0154 7501 JNZ 0157
0C1E:0156 F4 HLT
--- End code ---
222Lab_Test222:
--- Quote from: fzabkar on December 16, 2024, 08:37:03 am ---BIOS structure
--- Code: ---0x0000 - 0x1FFF -- mostly empty, file header
0x2000 - 0x2FFF -- 3mode FD-BIOS KDX4.1.34 for FDC37C661 by WACOM 1997.04 Rev.Sun&Moon
0x3000 - 0x3FFF -- ROM disk XBIOS KDX4.1.30 1995.12 SUN
0x4000 - 0x4FFF -- PCD BIOS Ver2.03 Copyright 1997 WACOM Engineering Co., Ltd.
0x5000 - 0x5FFF --
0x6000 - 0x98FF --
0x9900 - 0xD1FF --
0xD200 - 0xD4FF --
0xD500 - 0xEFFF -- XBIOS 1.00 1995 PCMCIA Socket Service 2.10, Driver Rev 1.01, Copyright WACOM Engineering 1996.01
0xF000 - 0xF7FF --
0xF800 - 0xFFFF -- KDX.1.34A Copyright 1993,¥¥,97 WACOM
--- End code ---
On power-up, the BIOS jumps to 0xF000 in KDX.SYS and begins POST-ing.
I have used DEBUGX to disassemble the code. Offset 0x100 in the listing equates to offset 0xF000 in KDX.SYS.
If a particular test fails, it results in a CPU halt (HLT). There does not appear to be a diagnostic port.
This is the first test:
--- Code: ---0C1E:0119 66C1E210 SHL EDX,10
0C1E:011D B044 MOV AL,44
0C1E:011F E611 OUT 11,AL
0C1E:0121 B092 MOV AL,92
0C1E:0123 E637 OUT 37,AL
0C1E:0125 B00F MOV AL,0F
0C1E:0127 E637 OUT 37,AL
0C1E:0129 B00B MOV AL,0B
0C1E:012B E637 OUT 37,AL
0C1E:012D B000 MOV AL,00
0C1E:012F E65F OUT 5F,AL
0C1E:0131 E652 OUT 52,AL
0C1E:0133 BA7100 MOV DX,0071
0C1E:0136 BB1000 MOV BX,0010
0C1E:0139 B90300 MOV CX,0003
0C1E:013C B4FF MOV AH,FF
0C1E:013E 8AC3 MOV AL,BL
0C1E:0140 E677 OUT 77,AL
0C1E:0142 EB00 JMP 0144
0C1E:0144 8AC4 MOV AL,AH
0C1E:0146 EE OUT DX,AL
0C1E:0147 EB00 JMP 0149
0C1E:0149 8AC7 MOV AL,BH
0C1E:014B E677 OUT 77,AL
0C1E:014D EB00 JMP 014F
0C1E:014F EC IN AL,DX
0C1E:0150 EB00 JMP 0152
0C1E:0152 3AC4 CMP AL,AH
0C1E:0154 7501 JNZ 0157
0C1E:0156 F4 HLT
--- End code ---
--- End quote ---
Put in non working EPROMS? High or Low?
Can you make .BIN file?
squadchannel:
worked ROM and the didn't work ROM are exactly the same binary.
the problem is not in the ROM but still elsewhere. therefore, replacing the ROM will not change anything.
Is it an RTC, is there more to it, or can it be cured with a magic finger like in curiousMarc's PS/2 repair video? 8) I don't know. :-//
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version