Thank you for your patience. Ya.. that 486 is going to be a challenge. I've never seen anything this detached from the board. Real mystery as to how that happened.
@@atheatos Good to hear they worked, that's encouraging. The keyboard not working on the 368 was unexpected, I tested the connector and it has continuity to the board. I'm hoping I can test the chip in the Tl866, I'm going to socket that (the 486 has the same chip already socketed conveniently). Traces looked complete but I need to put it under the microscope first before I commit to desoldering that 40 pin beast.
Btw I listened closely to the way you pronounce your channel name and used google translate, I hope that wasn't painful to listen to. I know how to say invisible in greek now.
If connectivity from the connector to the keyboard controller is fine, it is probably the controller itself. That is rare to happen but yeah your best thing to do is to socket it and swap it from another M/B. BTW Check that the keyboard also gets power and GND. I have to go and check 20 M/Bs now, no space to move here 😢.
Here's another quick tip. You don't have to use EPROMs for the BIOS on motherboards like these. You can just as well use EEPROMs. The advantage of doing so is that they are electrically erasable (thus the extra 'E') and if you make a mistake or simply want to reprogram them you can skip the UV erase step. The programmer can erase them. I use Winbond W27C512 chips in this role. They are pin compatible with the 27C512 EPROMs, easy to find and cheap.
Absolutely agree and I just ordered some of these yesterday coincidentally. Thank you for verifying the W27C512 will work. The 15 minutes of waiting for the UV gets a little old when you are trying multiple Bios Roms. I really like modifying these old boards with upgraded tech.
@@esc2dos Yes they definitely work. I even have one in a XT clone with no problems. Once caveat when using them to substitute for 27C256 or 27C128 (which you can definitely do) is that you won't know the state of the extra address lines, so in order to prevent any unexpected behavior you have to fill the EEPROM with multiple images of the BIOS (2 images one after the other for 256kbit images, 4 of them for the 128kbit ones).
@@stamasd8500 Cool, Ya. I've watched Adrian Black fill in the blank area with a second copy, Gotcha. I'm only dealing with 386/486s so I'll be using W27C512 and W27C010 chips. Got enough ancient stuff overflowing already, can't imagine adding XTs and 286's on to the pile :)
@@esc2dos As for modifying old boards with upgraded tech... that XT clone was upgraded more or less to the max save from changing it into a completely different class. I have found in the original BIOS image several empty areas into which I was able to cram 2 important things: the XT-IDE ROM image, and the BIOS from an 8-bit floppy controller, which allowed for the use of a multi-IO card (16-bit ISA but it works fine in an 8-bit slot as well) with full IDE support and 1.44M floppy support. Also a 16-bit VGA card that works fine in an 8-bit slot, there are quite a few of those. And no extra ROM card or discrete XT-IDE card needed, since all the important bits of the ROM are now in the system BIOS chip. That leaves 6 ISA slots open for other upgrades.
@@stamasd8500 That's intense, I wasn't aware changes that drastic could be made . I intend on releasing a video about my Fortiva 5000 machine. If I can ask your opinion? The Board (CPC-2800) refuses anything other than the original hard drive. No combination of adapters/SD/CF cards or 6.22 or Dos 7.1 will work. It can recognize them but always fails at formatting (just crashes before it starts the format). I've tried disabling the onboard IDE and using 2 different VLB controller cards, same issue. Do you think that could be changed with either modifying or using a different Bios? I'm wondering if there's a Mr. Bios perhaps that would fix this issue. Is this a chipset issue rather than a Bios issue is what I'm wondering?
Thank you for the mention.
This 486 M/B is probably fixable... but yeah... this will be a very hard one.
Thank you for your patience. Ya.. that 486 is going to be a challenge. I've never seen anything this detached from the board. Real mystery as to how that happened.
I had many cases like that and they worked in the end... but yeah all 3 sides and broken traces... it will be brutal to fix.
@@atheatos Good to hear they worked, that's encouraging. The keyboard not working on the 368 was unexpected, I tested the connector and it has continuity to the board. I'm hoping I can test the chip in the Tl866, I'm going to socket that (the 486 has the same chip already socketed conveniently). Traces looked complete but I need to put it under the microscope first before I commit to desoldering that 40 pin beast.
Btw I listened closely to the way you pronounce your channel name and used google translate, I hope that wasn't painful to listen to. I know how to say invisible in greek now.
If connectivity from the connector to the keyboard controller is fine, it is probably the controller itself.
That is rare to happen but yeah your best thing to do is to socket it and swap it from another M/B.
BTW Check that the keyboard also gets power and GND.
I have to go and check 20 M/Bs now, no space to move here 😢.
Here's another quick tip. You don't have to use EPROMs for the BIOS on motherboards like these. You can just as well use EEPROMs. The advantage of doing so is that they are electrically erasable (thus the extra 'E') and if you make a mistake or simply want to reprogram them you can skip the UV erase step. The programmer can erase them.
I use Winbond W27C512 chips in this role. They are pin compatible with the 27C512 EPROMs, easy to find and cheap.
Absolutely agree and I just ordered some of these yesterday coincidentally. Thank you for verifying the W27C512 will work. The 15 minutes of waiting for the UV gets a little old when you are trying multiple Bios Roms. I really like modifying these old boards with upgraded tech.
@@esc2dos Yes they definitely work. I even have one in a XT clone with no problems. Once caveat when using them to substitute for 27C256 or 27C128 (which you can definitely do) is that you won't know the state of the extra address lines, so in order to prevent any unexpected behavior you have to fill the EEPROM with multiple images of the BIOS (2 images one after the other for 256kbit images, 4 of them for the 128kbit ones).
@@stamasd8500 Cool, Ya. I've watched Adrian Black fill in the blank area with a second copy, Gotcha. I'm only dealing with 386/486s so I'll be using W27C512 and W27C010 chips. Got enough ancient stuff overflowing already, can't imagine adding XTs and 286's on to the pile :)
@@esc2dos As for modifying old boards with upgraded tech... that XT clone was upgraded more or less to the max save from changing it into a completely different class. I have found in the original BIOS image several empty areas into which I was able to cram 2 important things: the XT-IDE ROM image, and the BIOS from an 8-bit floppy controller, which allowed for the use of a multi-IO card (16-bit ISA but it works fine in an 8-bit slot as well) with full IDE support and 1.44M floppy support. Also a 16-bit VGA card that works fine in an 8-bit slot, there are quite a few of those. And no extra ROM card or discrete XT-IDE card needed, since all the important bits of the ROM are now in the system BIOS chip. That leaves 6 ISA slots open for other upgrades.
@@stamasd8500 That's intense, I wasn't aware changes that drastic could be made . I intend on releasing a video about my Fortiva 5000 machine. If I can ask your opinion? The Board (CPC-2800) refuses anything other than the original hard drive. No combination of adapters/SD/CF cards or 6.22 or Dos 7.1 will work. It can recognize them but always fails at formatting (just crashes before it starts the format). I've tried disabling the onboard IDE and using 2 different VLB controller cards, same issue. Do you think that could be changed with either modifying or using a different Bios? I'm wondering if there's a Mr. Bios perhaps that would fix this issue. Is this a chipset issue rather than a Bios issue is what I'm wondering?