68 lines
1.7 KiB
Go
68 lines
1.7 KiB
Go
// Copyright Terence J. Boldt (c)2021-2022
|
|
// Use of this source code is governed by an MIT
|
|
// license that can be found in the LICENSE file.
|
|
|
|
// This file provides conversion to and from ProDOS time format
|
|
|
|
package prodos
|
|
|
|
import (
|
|
"time"
|
|
)
|
|
|
|
// DateTimeToProDOS converts Time to ProDOS date time
|
|
// 49041 ($BF91) 49040 ($BF90)
|
|
//
|
|
// 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0
|
|
// +-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
|
|
// DATE: | year | month | day |
|
|
// +-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
|
|
//
|
|
// 49043 ($BF93) 49042 ($BF92)
|
|
//
|
|
// 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0
|
|
// +-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
|
|
// TIME: | hour | | minute |
|
|
// +-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
|
|
func DateTimeToProDOS(dateTime time.Time) []byte {
|
|
year := dateTime.Year() % 100
|
|
month := dateTime.Month()
|
|
day := dateTime.Day()
|
|
hour := dateTime.Hour()
|
|
minute := dateTime.Minute()
|
|
|
|
buffer := make([]byte, 4)
|
|
buffer[0] = ((byte(month) & 15) << 5) + byte(day)
|
|
buffer[1] = (byte(year) << 1) + (byte(month) >> 3)
|
|
buffer[2] = byte(minute)
|
|
buffer[3] = byte(hour)
|
|
|
|
return buffer
|
|
}
|
|
|
|
// DateTimeFromProDOS converts Time from ProDOS date time
|
|
func DateTimeFromProDOS(buffer []byte) time.Time {
|
|
if buffer[0] == 0 &&
|
|
buffer[1] == 0 &&
|
|
buffer[2] == 0 &&
|
|
buffer[3] == 0 {
|
|
return time.Time{}
|
|
}
|
|
twoDigitYear := buffer[1] >> 1
|
|
var year int
|
|
if twoDigitYear < 76 {
|
|
year = 2000 + int(twoDigitYear)
|
|
} else {
|
|
year = 1900 + int(twoDigitYear)
|
|
}
|
|
|
|
month := int(buffer[0]>>5 + (buffer[1]&1)<<3)
|
|
day := int(buffer[0] & 31)
|
|
hour := int(buffer[3])
|
|
minute := int(buffer[2])
|
|
|
|
parsedTime := time.Date(year, time.Month(month), day, hour, minute, 0, 0, time.Local)
|
|
|
|
return parsedTime
|
|
}
|