izapple2/cardThunderClockPlus.go
2019-11-09 18:13:19 +01:00

50 lines
1.1 KiB
Go

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