Changes
== About uRTC-8 ==
uRTC-8 is a universal RTC that can be connected via a Z80 shim to any Z80 computer that has a socketed CPU. It uses an 8 bit comparator and a set of jumpers to enable I/O base address selection, just like uIDE-8. The RTC used is an Epson RTC72421 which has 16 registers, directly accessible via IN and OUT instructions. As a result, the base I/O address is a four bit number between 0000 and 1111 (0-15), putting the device at any of the I/O addresses 00h, 10h, 20h, 30h, 40h, 50h, 60h, 70h, 80h, 90h, A0h, B0h, C0h, D0h, E0h or F0h. From that address any of these base addresses to xFh [base address + 0Fh] are the 16 registers of the Epson RTC.
uRTC -8 is powered by the host computer, but also has a battery backed supply to maintain the time and date when the host is powered down. The battery is a common CR2032 3v button cell.
== Project status ==
As of this time (April 2019), the uRTC boards are designed and in fabrication. Work has started on the utilities.
== Downloads ==
Along with the device itself, there are downloadable utilities:
* uRTC.COM allows the user to set and get the time on the RTC chip.
* uRTCTX.com transfers the time and date to the host computer's operating system (normally CP/M). If you have uIDE-8 installed, add a call to this program to your PROFILE.SUB and locate the program on an IDE partition so it loads and runs faster.
* uRTCTX.FID performs the same function as uRTCTX.COM, except as a FID (field installable driver). Use this to set the PcW system clock when booting into LocoScript (also works under CP/M but is slower to load than a copy of uRTCTX.COM that's sitting on a uIDE partition).
=== uRTC.COM ===
Use to set or display the time and date on uRTC-8.
usage: uRTC - show date and time from the RTC clock"
uRTC [[day] [dd/mm/yy] [hh:mm[:ss]]] [-b ADDR]"
set RTC day/date/time"
-b ADDR specify alternative uRTC base I/O register"
(default is A0)"
The following examples should illustrate its use:
A>uRTC
Tue 10 Nov 2017 12:42:36
A>uRTC 18/12/18
Tue 18 Dec 2018 12:42:52
A>uRTC 17:05
Tue 18 Dec 2018 17:05:00
A>uRTC 17:05:55
Tue 18 Dec 2018 17:05:55
A>uRTC
Tue 18 Dec 2018 17:05:13
=== uRTCTX.COM ===
A small utility that copies the time from uRTC-8 to the PCW's CP/M internal clock. Install it to the boot disk and call from PROFILE.SUB. If you have uIDE-8 installed, copy it to an IDE drive and call from PROFILE.SUB for improved speed.
=== uRTCTX.FID ===
A small FID that copies the time from uRTC-8 to the PCW's CP/M internal clock. Install it to the boot disk / start of day disk and it will run each time the PcW cold boots. (Note, requires CP/M Plus v.1.15 or higher).
== Technical info ==
