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SystemSoft Bios dump garbled

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First post, by Scorpwanna

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I have an old Hyundai Neuron Lite 425SX from around 1992 that finally fell apart due to the plastic cracking to pieces. It was last booted in 2021 and worked fine, now it wont boot at all.

I want to preserve as much as I can of the system, so I bought a chip reader to extract it's BIOS. Most bios files I see have year information in them and company information. But, the dumps I got from these 2 chips is a garbled mess even though I followed the steps to dump using the exact chip settings. I want to say that it seems to be some form of byte swapping going on, maybe an algorithmic shift in the data. I was hoping someone could look at the files and see if it's possible to unscramble them.

Thanks in advance.

Reply 1 of 20, by weedeewee

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the N28F010 contents seem to have some odd bit errors.
just a quick glance at the contents shows several mentions of 'memorx' which I'm fairly certain should be 'memory'

Can you describe how and what equipment you used to read it out and read it out again after cleaning all the contact surfaces on the chips and the reader.

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Reply 2 of 20, by Disruptor

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It is likely that the BIOS is split bytewise into 2 ROMS. So you'll find a string "ABCDEFGH" into 2 ROMS: "ACEG" and "BDFH".
This is often used in 286 and 386 SX / SL systems because the penalty for an 8 bit BIOS access would decrease performance if the BIOS is not shadowed.

Which CPU is in it?

Correction: It looks like a system BIOS and a VGA BIOS.

Reply 3 of 20, by mkarcher

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Actually, both BIOS dumps are obviously unreliable. The small dump most likely should read "Copyright SystemSoft Corporation, 1990-1991." instead of "Bopxrhghp RxrpemRobp Borpor`phoj( 0880(0880*". Bits 0 and 2 (values 01 and 04) are bad. This looks very much like a contact problem to me. As the dump of the big ROM contains similar errors, I suspect that the PLCC32 socket in the reader is correded and doesn't make sufficient contact to the ROM chips. If you use an PLCC32-to-DIP adapter on your reader, the issue might also be a bad contact between the adapter and the reader. Probably the issue can be fixed using contact cleaner and mechanical scraping.

There is no reason to assume bits being swapped or bytes being interleaved given the data in the ROM files. weedeewee already pointed out that the big ROM dump contains similar issues. The start of the big ROM dump is the graphics BIOS, which is 32K. As a legacy EGA/VGA detection algorithm is looking for the string "IBM" in the video BIOS ROM, the graphics ROM is supposed to contain "IBM" at 1E, but this dump says "HBM" instead. Furthermore, it is supposed to read something like "SystemSoft Cirrus 6225 SGD BIOS "<CR><LF>"Copyright 1992 SystemSoft corp. - All Rights Reserved"<CR><LF> (not sure about the "SGD" part). but it reads "RxrpemRobp Bhrrur 2225 RG@ BHOR "<CR><LF>"Bopxrhghp 0882 RxrpemRobp Borp* - @hh Rhghpr Rererre`"<CR><LF>. I don't know what the second 32K of the big ROM dump are for, but the final 64K are the standard mainboard BIOS.

The small ROM might contain power management firmware (if the processor is an SL-type processor with system management mode - a 486SLC would be an obvious choice for a laptop like this) or fimrware for a keyboard/system management processor.

I don't see any obvious signs of addressing errors, so it's "just" two data bits that are bad.

Reply 4 of 20, by mkarcher

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Well, actually, it doesn't look like a bad contact, but like a short between data bit D0 and data bit D2. Because TTL chips (and TTL-compatible chips) are stronger at pulling an output low than at pulling it high, this will result in D0 and D2 always having the same level, which is low if at least one bit of D0 and D2 is low, and high if both are high.

I hacked a JavaScript font viewer that you can use to look at the VGA fonts in the VGA BIOS of your dump. You will see that all the characters are present, and that bad bits are always in the same columns, which again clearly shows that addressing works, but some specific data bits are wrong. You can use that tool by visiting https://karcherm.github.io/fontview/ To look at the fonts included in your ROM dump, use the button next to "Use part of local file" and click the "Browse..." button (your browser may use your native language instead of "Browse..."), and select the 28F010 file. Some new fields will appear. To look at the different fonts, use

  • Start = 0x4502, Height = 8 for the 8x8 font
  • Start = 0x4D03, Height = 14 for the 8x14 font
  • Start = 0x5B321, Height = 16 for the 8x16 font

Reply 5 of 20, by Scorpwanna

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weedeewee wrote on 2025-10-11, 10:31:

the N28F010 contents seem to have some odd bit errors.
just a quick glance at the contents shows several mentions of 'memorx' which I'm fairly certain should be 'memory'

Can you describe how and what equipment you used to read it out and read it out again after cleaning all the contact surfaces on the chips and the reader.

The chip reader is a XGecu TL866II Plus Model T48. I bought it new, some of the adapter pieces do look like they have mild corrosion (whiteish film) on the back of them around the soldier joints though. The PLCC32 adapter I used doesn't have any corrosion. What can I use to clean the contact surfaces?

Reply 6 of 20, by Scorpwanna

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Disruptor wrote on 2025-10-11, 10:32:
It is likely that the BIOS is split bytewise into 2 ROMS. So you'll find a string "ABCDEFGH" into 2 ROMS: "ACEG" and "BDFH". Thi […]
Show full quote

It is likely that the BIOS is split bytewise into 2 ROMS. So you'll find a string "ABCDEFGH" into 2 ROMS: "ACEG" and "BDFH".
This is often used in 286 and 386 SX / SL systems because the penalty for an 8 bit BIOS access would decrease performance if the BIOS is not shadowed.

Which CPU is in it?

Correction: It looks like a system BIOS and a VGA BIOS.

intel 486SX, Here's an Excel worksheet of the components on the board.

Reply 7 of 20, by Scorpwanna

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mkarcher wrote on 2025-10-11, 11:07:
Actually, both BIOS dumps are obviously unreliable. The small dump most likely should read "Copyright SystemSoft Corporation, 19 […]
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Actually, both BIOS dumps are obviously unreliable. The small dump most likely should read "Copyright SystemSoft Corporation, 1990-1991." instead of "Bopxrhghp RxrpemRobp Borpor`phoj( 0880(0880*". Bits 0 and 2 (values 01 and 04) are bad. This looks very much like a contact problem to me. As the dump of the big ROM contains similar errors, I suspect that the PLCC32 socket in the reader is correded and doesn't make sufficient contact to the ROM chips. If you use an PLCC32-to-DIP adapter on your reader, the issue might also be a bad contact between the adapter and the reader. Probably the issue can be fixed using contact cleaner and mechanical scraping.

There is no reason to assume bits being swapped or bytes being interleaved given the data in the ROM files. weedeewee already pointed out that the big ROM dump contains similar issues. The start of the big ROM dump is the graphics BIOS, which is 32K. As a legacy EGA/VGA detection algorithm is looking for the string "IBM" in the video BIOS ROM, the graphics ROM is supposed to contain "IBM" at 1E, but this dump says "HBM" instead. Furthermore, it is supposed to read something like "SystemSoft Cirrus 6225 SGD BIOS "<CR><LF>"Copyright 1992 SystemSoft corp. - All Rights Reserved"<CR><LF> (not sure about the "SGD" part). but it reads "RxrpemRobp Bhrrur 2225 RG@ BHOR "<CR><LF>"Bopxrhghp 0882 RxrpemRobp Borp* - @hh Rhghpr Rererre`"<CR><LF>. I don't know what the second 32K of the big ROM dump are for, but the final 64K are the standard mainboard BIOS.

The small ROM might contain power management firmware (if the processor is an SL-type processor with system management mode - a 486SLC would be an obvious choice for a laptop like this) or fimrware for a keyboard/system management processor.

I don't see any obvious signs of addressing errors, so it's "just" two data bits that are bad.

I had google gemini helping me and it was suggesting the byte swapping. The reader I have is Vikye USB Programmer, TL866II Model T48, it says XGecu Pro on the back of it. I just bought it brand new, but some of the adapters do look like they have mild corrosion on the back of the chips, or some sort of substance perhaps when the adapters were created.

Reply 8 of 20, by Scorpwanna

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The only thing I have to clean with is Isopropyl Alcohol 91%, no other cleaners.

Reply 9 of 20, by jakethompson1

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Your AI is reading too much into other conversations about BIOSes that are split across an odd and even ROM, that's why it latched on to byte swapping being an issue trying to read a BIOS chip dump

Reply 10 of 20, by Scorpwanna

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Attaching 2 pictures, one of the device with chip in it, and a screenshot of the program after reading it.

Reply 11 of 20, by mkarcher

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Scorpwanna wrote on 2025-10-12, 03:03:

The only thing I have to clean with is Isopropyl Alcohol 91%, no other cleaners.

You don't need to clean. As I wrote in my second post, you have a short (circuit), that is an unwanted connection, between two pins. I marked the relevant pins in your photo:

The attachment xgeku.jpg is no longer available

The issue might be on your adapter or in the programmer. If you perform a continuity test or a resistance measurements, you will find that the pins I drew the red lines between are connected to each other, but they must not be connected. It is much easier to test on the soldered DIP pins (lower red line) than on the PLCC pins with standard multimeter probes, and you don't need to test both red lines.

If you can test for continuity or resistance, please test (with the programmer powered off) whether you can still see the direct connection between these pins first with the adapter installed in the programmer (like on your photo), and then just with the adapter. If the connection is gone after removing the adapter from the programmer, the programmer is faulty, otherwise the adapter is faulty. If the adapter is faulty, you might be lucky and find excess solder on the back side that accidentally connects these pins, which you can just break off. On the other hand, if the programmer is faulty and you are not experienced with electronics, it's likely a good idea to have the seller replace the faulty programmer by a working one.

Reply 12 of 20, by Scorpwanna

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I found an old motherboard I had in a box, it's from a Compaq ProLinea motherboard, it too has the same size chip. A TMS27PC010, I inserted it into the adapter to read it and get this bit of code:

€BH-G@5022/5020/5022/5028 RG@ BHOR Rerrhoj 0*20
Bopxrhghp 0882-0882 Bhrrur Hoghb( Hjb* @hh Rhghpr Rererre`*
Bopxrhghp 0887-0880 Pu``peh Borp* @hh Rhghpr Rererre`*
Bopxrhghp Bomp`p Bompuper Borpor`phoj 0882(0882*

I'm thinking the adapter with this chip reader isn't working as expected.

Reply 13 of 20, by Scorpwanna

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mkarcher wrote on 2025-10-12, 06:06:
You don't need to clean. As I wrote in my second post, you have a short (circuit), that is an unwanted connection, between two […]
Show full quote
Scorpwanna wrote on 2025-10-12, 03:03:

The only thing I have to clean with is Isopropyl Alcohol 91%, no other cleaners.

You don't need to clean. As I wrote in my second post, you have a short (circuit), that is an unwanted connection, between two pins. I marked the relevant pins in your photo:

The attachment xgeku.jpg is no longer available

The issue might be on your adapter or in the programmer. If you perform a continuity test or a resistance measurements, you will find that the pins I drew the red lines between are connected to each other, but they must not be connected. It is much easier to test on the soldered DIP pins (lower red line) than on the PLCC pins with standard multimeter probes, and you don't need to test both red lines.

If you can test for continuity or resistance, please test (with the programmer powered off) whether you can still see the direct connection between these pins first with the adapter installed in the programmer (like on your photo), and then just with the adapter. If the connection is gone after removing the adapter from the programmer, the programmer is faulty, otherwise the adapter is faulty. If the adapter is faulty, you might be lucky and find excess solder on the back side that accidentally connects these pins, which you can just break off. On the other hand, if the programmer is faulty and you are not experienced with electronics, it's likely a good idea to have the seller replace the faulty programmer by a working one.

The programmer device successfully read an awards bios, it has System halt
DISK BOOT FAILURE, INSERT SYSTEM DISK AND PRESS ENTERKeyboard controller errorKeyboard error or no keyboard presentBIOS ROM checksum error
Detecting floppy drive A media...Drive media is : 1.44Mb

At the end of the bios.

Reply 14 of 20, by Scorpwanna

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I took the chip out and tested the adapter just by itself. This is what was reported.

APP Version : 13.04 Model : T48 MFG:2025-05-30
Device : AT27C256R @PLCC32
Bad Pin: ZIF2 - PIN#2
Bad Pin: ZIF3 - PIN#3
Bad Pin: ZIF4 - PIN#4
Bad Pin: ZIF5 - PIN#5
Bad Pin: ZIF6 - PIN#6
Bad Pin: ZIF7 - PIN#7
Bad Pin: ZIF8 - PIN#8
Bad Pin: ZIF9 - PIN#9
Bad Pin: ZIF10 - PIN#10
Bad Pin: ZIF11 - PIN#11
Bad Pin: ZIF14 - PIN#14
Bad Pin: ZIF26 - PIN#18
Bad Pin: ZIF27 - PIN#19
Bad Pin: ZIF28 - PIN#20
Bad Pin: ZIF29 - PIN#21
Bad Pin: ZIF30 - PIN#22
Bad Pin: ZIF31 - PIN#23
Bad Pin: ZIF32 - PIN#24
Bad Pin: ZIF33 - PIN#25
Bad Pin: ZIF35 - PIN#27
Bad Pin: ZIF36 - PIN#28
Bad Pin: ZIF37 - PIN#29
Bad Pin: ZIF38 - PIN#30
Bad Pin: ZIF39 - PIN#31
Bad Pin: ZIF40 - PIN#32

Reply 15 of 20, by mkarcher

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Scorpwanna wrote on 2025-10-12, 06:52:
The programmer device successfully read an awards bios, it has System halt DISK BOOT FAILURE, INSERT SYSTEM DISK AND PRESS ENTER […]
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The programmer device successfully read an awards bios, it has System halt
DISK BOOT FAILURE, INSERT SYSTEM DISK AND PRESS ENTERKeyboard controller errorKeyboard error or no keyboard presentBIOS ROM checksum error
Detecting floppy drive A media...Drive media is : 1.44Mb

At the end of the bios.

That's OK. Was that award BIOS also a PLCC chip, or was that BIOS a DIP chip? If it was a DIP28, that result indicate mean anything about your problem, becasue DIP28 doesn't use one of the affected pins.

Scorpwanna wrote on 2025-10-12, 06:57:
I took the chip out and tested the adapter just by itself. This is what was reported. […]
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I took the chip out and tested the adapter just by itself. This is what was reported.

APP Version : 13.04 Model : T48 MFG:2025-05-30
Device : AT27C256R @PLCC32
Bad Pin: ZIF2 - PIN#2
Bad Pin: ZIF3 - PIN#3
Bad Pin: ZIF4 - PIN#4
Bad Pin: ZIF5 - PIN#5
Bad Pin: ZIF6 - PIN#6
Bad Pin: ZIF7 - PIN#7
Bad Pin: ZIF8 - PIN#8
Bad Pin: ZIF9 - PIN#9
Bad Pin: ZIF10 - PIN#10
Bad Pin: ZIF11 - PIN#11
Bad Pin: ZIF14 - PIN#14
Bad Pin: ZIF26 - PIN#18
Bad Pin: ZIF27 - PIN#19
Bad Pin: ZIF28 - PIN#20
Bad Pin: ZIF29 - PIN#21
Bad Pin: ZIF30 - PIN#22
Bad Pin: ZIF31 - PIN#23
Bad Pin: ZIF32 - PIN#24
Bad Pin: ZIF33 - PIN#25
Bad Pin: ZIF35 - PIN#27
Bad Pin: ZIF36 - PIN#28
Bad Pin: ZIF37 - PIN#29
Bad Pin: ZIF38 - PIN#30
Bad Pin: ZIF39 - PIN#31
Bad Pin: ZIF40 - PIN#32

That's normal. The pin test tests whether the programmer has connectivity to the pins of the ROM. If there is no ROM inserted, the pin check is supposed to fail.

Reply 16 of 20, by Scorpwanna

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mkarcher wrote on 2025-10-12, 06:06:
You don't need to clean. As I wrote in my second post, you have a short (circuit), that is an unwanted connection, between two […]
Show full quote
Scorpwanna wrote on 2025-10-12, 03:03:

The only thing I have to clean with is Isopropyl Alcohol 91%, no other cleaners.

You don't need to clean. As I wrote in my second post, you have a short (circuit), that is an unwanted connection, between two pins. I marked the relevant pins in your photo:

The attachment xgeku.jpg is no longer available

The issue might be on your adapter or in the programmer. If you perform a continuity test or a resistance measurements, you will find that the pins I drew the red lines between are connected to each other, but they must not be connected. It is much easier to test on the soldered DIP pins (lower red line) than on the PLCC pins with standard multimeter probes, and you don't need to test both red lines.

If you can test for continuity or resistance, please test (with the programmer powered off) whether you can still see the direct connection between these pins first with the adapter installed in the programmer (like on your photo), and then just with the adapter. If the connection is gone after removing the adapter from the programmer, the programmer is faulty, otherwise the adapter is faulty. If the adapter is faulty, you might be lucky and find excess solder on the back side that accidentally connects these pins, which you can just break off. On the other hand, if the programmer is faulty and you are not experienced with electronics, it's likely a good idea to have the seller replace the faulty programmer by a working one.

The only 2 multimeters I have are both blown out (not by me). I'm not too experienced with electronics.

Reply 17 of 20, by Scorpwanna

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The Awards bios was a DIP i believe (I didn't have to use an adapter) it was maybe 2 inches long.

Reply 18 of 20, by mkarcher

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The soldering of that adapter looks awful. I wouldn't be surprised if there actually is a solder bridge between pins 13 and 15 of the PLCC socket. Too bad you can't see that, because that bridge would be below the DIP pins. I marked the problematic area in your picture, note the red rectangle to mark the orientation of the adapter. The two pins marked with the red circles are most likely connected in the adapter. If you happen to know someone locally, he/she may just reflow the two pins to try to clear the short. Otherwise, you should try to get that adapter replaced.

Reply 19 of 20, by Scorpwanna

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mkarcher wrote on 2025-10-12, 11:41:

The soldering of that adapter looks awful. I wouldn't be surprised if there actually is a solder bridge between pins 13 and 15 of the PLCC socket. Too bad you can't see that, because that bridge would be below the DIP pins. I marked the problematic area in your picture, note the red rectangle to mark the orientation of the adapter. The two pins marked with the red circles are most likely connected in the adapter. If you happen to know someone locally, he/she may just reflow the two pins to try to clear the short. Otherwise, you should try to get that adapter replaced.

I had thought about just finding a replacement, thanks for all your help and info.