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Talk:Programmable interval timer

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Would it possible for somebody to get information on how the PIT is activated for this page?

Jatos 22:17, 3 December 2006 (UTC)[reply]

PIT does not have a separate crystal

[edit]

The comment regarding about the PIT having a separate crystal is wrong. The original IBM PCs had a single 14.31818 MHz crystal (four times the NTSC colourburst rate) for everything. It was divided by 3 to get 4.77MHz for the CPU and 12 to get 1.19MHz for the PIT. Thus the exact rate is (30*525*227.5)/(1.001*3) = 1193181.8181... Hz. —Preceding unsigned comment added by 91.153.27.229 (talk) 10:41, 22 June 2009 (UTC)[reply]