mirror of
https://github.com/ivanizag/izapple2.git
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50 lines
1.1 KiB
Go
50 lines
1.1 KiB
Go
package apple2
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/*
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ThunderClock`, real time clock card.
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See:
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https://ia800706.us.archive.org/22/items/ThunderClock_Plus/ThunderClock_Plus.pdf
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https://prodos8.com/docs/technote/01/
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https://www.semiee.com/file/backup/NEC-D1990.pdf
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uPD1990AC hookup:
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bit 0 = data in
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bit 1 = CLK
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bit 2 = STB
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bit 3 = C0
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bit 4 = C1
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bit 5 = C2
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bit 7 = data out
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*/
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type cardThunderClockPlus struct {
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microPD1990ac
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cardBase
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}
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func (c *cardThunderClockPlus) assign(a *Apple2, slot int) {
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c.addCardSoftSwitchR(0, func(*ioC0Page) uint8 {
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bit := c.microPD1990ac.out()
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// Get the next data bit from uPD1990AC on the MSB
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if bit {
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return 0x80
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}
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return 0
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}, "THUNDERCLOCKR")
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c.addCardSoftSwitchW(0, func(_ *ioC0Page, value uint8) {
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dataIn := (value & 0x01) == 1
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clock := ((value >> 1) & 0x01) == 1
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strobe := ((value >> 2) & 0x01) == 1
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command := (value >> 3) & 0x07
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/* fmt.Printf("[cardThunderClock] dataIn %v, clock %v, strobe %v, command %v.\n",
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dataIn, clock, strobe, command) */
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c.microPD1990ac.in(clock, strobe, command, dataIn)
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}, "THUNDERCLOCKW")
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c.cardBase.assign(a, slot)
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}
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