Contains a rechargeable battery, five chips, a quartz crystal, a 8bit general-purpose I/O port (9pin male DSUB), and a few odds and ends.
The RTC is a HD146818 (which is a [[PC compatible RTC chip]]).
== Technical ==
Contains a following components: HD146818P ([[PC compatible RTCchip|PC-style RTC]]), a TMP[[Z80 PIO|Z84C20]]P ([[Z80 PIO]]), three logic chips74LS00 (Quad NAND), and a 3.6V battery. * Reportedly: DK-Tronics RTC module used the [[Z80 PIO]] chip to address the RTC itself as Port A of the PIO74LS138 (demux), with a 9-pin user i/o port as Port B. FBE0h Dk'tronics Real Time Clock - probably [[Z80 PIO]] Port A Data 74LS175 (RTC Data bus4bit latch) FBE1h Dk'tronics Real Time Clock - MAYBE [[Z80 PIO]] Port B Data , 9pin male DSUB connector (General Purpose used as an 8bit general-purpose I/O Port) FBE2h Dk'tronics Real Time Clock - MAYBE [[Z80 PIO]] Port A Control FBE3h Dk'tronics Real Time Clock - probably [[Z80 PIO]] Port B Control FBE8h Dk'tronics Real Time Clock - (unknown purposeport), and a rechargeable 3.6V battery.
Not sure The battery is charged while the computer is switched on. The data will be retained for several months even if above addresses are correct, for example, A0 and A1 may be swapped..the computer is not used during this time.?
Uses a Z80 PIO chip to control the HD146818 RTC chip via port A. Do not use Port A seems to be as this will affect the plain RTC operation. FBE0h Dk'tronics Real Time Clock - [[Z80 PIO]] Port A Data Bus, there should be also ([[PC compatible RTC Read and Write signalschip|HD146818P]] RTC Data bus) FBE1h Dk'tronics Real Time Clock - [[Z80 PIO]] Port B Data, which are maybe found in the used for external control (General Purpose 8bit I/O Port) FBE2h Dk'tronics Real Time Clock - [[Z80 PIO]] Port A Control FBE3h Dk'tronics Real Time Clock - [[Z80 PIO]] Port B Control FBE8h Dk'tronics Real Time Clock - Control port for RTC chip (4bit latch) '''(details unknown purpose)''' port? Port B is connected directly to a standard 9-way connector on the left of the interface.
== Software ==
Included BASIC and CP/M+ drivers:
* RSX.BAS (loader) and RSX.BIN (binary)- allows to change the time under BASIC, using following RSX commands** |SETTIME,yy%,mm%,dd%,dayofweek%,hour%,min%,sec%** |ASKTIME,@yy%,@mm%,@dd%,@dayofweek%,@hour%,@min%,@sec%** |POKERTC,index%,value%** |PEEKRTC,index%,@value%** |TIMEON,xpos%,ypos%,interval%** |TIMEOFF** |ALARMON,hour%,min%,sec%,flag%** |ALARMOFF* CLOCK.COM - installs the clock under CP/M+ ** Thereafter, it should be accessible with standard DATE command, and, it should add timestamps to files).** According to english manual, time is set by "CLOCK dd/mm/yy hh/mm/ss" rather than by using the DATE command (?)** Unknown how the timestamps are stored on disk? The normal AMSDOS filesystem / directory entries don't include timestamps.** According german manual, something is (the startup message?) "Datomat RTC und Cdos sind Warenzeichen von CMS International" (=Datomat RTC and Cdos are trademarks of CMS International)
* CLOCK.COM - installs the clock under CP/M+ (thereafter, it should be accessible with standard DATE command, and, it should add timestamps to files).== Timestamps ==
Unknown how '''Below method uses Directory Entries with User Number 31 for Timestamps. Which should be incompatible with AMSDOS, so it is probably NOT used in the CPC. On the CPC, the timestamps are <might> be maybe stored on disk? The normal AMSDOS filesystem / directory entries don't include timestampsin the bootstrap sectors.. == Downloads == [[File:DkronicsRtcDriver.zip]] - none such? == Timestamps =='''
Time stamps - P2DOS and CP/M Plus support time stamps, which are stored in each fourth directory entry.
'''This method uses Directory Entries with User Number 31 for Timestamps. Which should be incompatible with AMSDOS, so it is probably NOT used in the CPC. On the CPC, the timestamps <might> be maybe stored in the bootstrap sectors...?'''
This entry contains the time stamps for the extents using the previous three directory entries. Note that you really have time stamps for each extent, no matter if it is the first extent of a file or not. The structure of time stamp entries is:
1 byte hour in BCD format
1 byte minute in BCD format
== Review ==
<gallery>
image:Amstrad Computer User8707 028.jpg
image:Amstrad Computer User8707 029.jpg
</gallery>
== Photos ==
<gallerycaption="dk'tronics Real Time Clock - 464/664 version">
image:RTC 001.jpg
image:RTC 002.jpg
image:RTC 011.jpg
image:RTC 012.jpg
</gallery>
<gallery caption="dk'tronics CPC6128 Real Time Clock 300dpi scans by Robcfg- 6128 version">
Image:RTC_Front.jpg|Front
Image:RTC_Back.jpg|Back
</gallery>
== Reviews ==
Reviewed in [[Amstrad Computer User]], July 1987, pages 28 and 29.
<gallery>
Amstrad Computer User8707 028.jpg
Amstrad Computer User8707 029.jpg
</gallery>
== Manuals ==
* [[Media:HD146818 datasheet.pdf|Hitachi HD146818 datasheet]]
* [[Media:Dktronics RTC Manual English.pdf|Dk'tronics RTC Manual (English)]]
* [[Media:Dktronics RTC Manual German.pdf|Dk'tronics RTC Manual (German)]]
== Downloads ==
* [[File:DktronicsRtcDriver.zip]] - none such?
[[Category:HardwarePeripherals]] [[Category:PeripheralsHardware]]