speedsys clcmos (software cmos clear?) \ VOGONS

speedsys clcmos (software cmos clear?)

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First post, by fabiensanglard

Posted on 2025-03-06, 02:26

fabiensanglard Offline

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Rank: Newbie
Posts: 41
Joined: 2017-08-18, 06:43

I have been trying to make speedsys work on my IBM PS/1 2168 for a while. I came across command clcmos.

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1speedsys clcmos

Which seems to have helped go past the atapi freeze.

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However after that my machine encountered an error "164 POST detected a base memory or extended memory size mismatch error".

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And the mouse stopped working.

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I ran the same command again and it fixed the machine. Problem solved but still I wonder how this command is working? I thought one was supposed to use jumpers or remove the battery to clear/reset the CMOS. Is there a software way to do that or speedsys command is mislabeled?

Reply 1 of 1, by bakemono

Posted on 2025-03-06, 09:56

bakemono Offline

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Posts: 871
Joined: 2018-01-15, 06:56

fabiensanglard wrote on 2025-03-06, 02:26:

I thought one was supposed to use jumpers or remove the battery to clear/reset the CMOS. Is there a software way to do that or speedsys command is mislabeled?

Yes, software can read and write the CMOS RAM, it's pretty simple. I/O port 0x70 holds the index/address and 0x71 holds the data byte.

GBAJAM 2024 submission on itch: https://90soft90.itch.io/wreckage

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