• Vobis HighScreen 486 Universal board

• DALLAS RTC coin cell empty

The motherboard's Real-Time Clock (RTC) chip contains a coin cell that may have drained, causing the loss of CMOS settings. This can result in an inability to save settings, causing system instability or failure to boot. To fix this, the RTC chip can be replaced with an equivalent or repaired by cutting into it and soldering on a new external coin cell holder. Replacement guides are available at https://github.com/necroware/nwX287 or https://github.com/necroware/nw12887, depending on the actual chip used.

• Slow cache without "dirty bit" chip installed

This motherboard uses a chipset that does not support a 7+1 bit tag system for cache, and requires a dedicated SRAM chip for dirty bit tracking. If this chip is not installed, all blocks in cache will always be marked as dirty and main memory latency will be significantly higher.