Native PS/2 mouse implementation for 386/486 boards using the keyboard controller

Discussion about old PC hardware.

Re: Native PS/2 mouse implementation for 386/486 boards using the keyboard controller

Postby feipoa » 2018-5-01 @ 17:59

Interesting. I have a board based on this same chipset and the PS/2 mod worked. It, too, originally had the L738C41 KBC.
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Re: Native PS/2 mouse implementation for 386/486 boards using the keyboard controller

Postby keropi » 2018-5-01 @ 18:52

Weird. Mine just won't boot , just like the kbc is missing. Could be a hardware config issue , go figure... :dead:
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Re: Native PS/2 mouse implementation for 386/486 boards using the keyboard controller

Postby feipoa » 2018-5-01 @ 19:51

Although, mine has the uncommon AWARD 4.20 BIOS. Looks like yours is AMI.
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Re: Native PS/2 mouse implementation for 386/486 boards using the keyboard controller

Postby keropi » 2018-5-01 @ 20:22

yep it's AMI ... the boring expected 386-era one LOL
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Re: Native PS/2 mouse implementation for 386/486 boards using the keyboard controller

Postby Rio444 » 2018-5-16 @ 15:41

feipoa wrote:The other thought is, I am using 2.05K for the current limiting resistor into the transistor's base. You are using 4.7K. Did you determine that 4.7K was needed, or did you just use whatever you had?

Forgive me for missing a long time.
The value of this resistor does not matter much.
It is needed to protect the output of KBC from overload.
In the first version of the device, it was completely absent.
But I'm not sure that all the KBC chips can survive after that.
I would recommend to use mouse data/clock pull-up resistors in the 2-3k range.
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