https://github.com/electrified/rc2014-ds1302-rtc

DS1302 Real Time Clock for the RC2014 computer
https://github.com/electrified/rc2014-ds1302-rtc

Last synced: 2 months ago
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DS1302 Real Time Clock for the RC2014 computer

• Host: GitHub
• URL: https://github.com/electrified/rc2014-ds1302-rtc
• Owner: electrified
• Created: 2018-01-27T17:46:06.000Z (almost 7 years ago)
• Default Branch: main
• Last Pushed: 2024-06-28T22:09:57.000Z (7 months ago)
• Last Synced: 2024-08-04T16:06:21.872Z (6 months ago)
• Language: Shell
• Homepage:
• Size: 5.43 MB
• Stars: 22
• Watchers: 7
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

Awesome Lists containing this project

• awesome-rc2014 - DS1302 Real Time Clock

README

        
# DS1302 Real Time Clock for the RC2014 computer

![Picture of the board](./board-r1.jpg?raw=true)

## The board

RomWBW has code to support a DS1302 Real Time Clock, enabling files to be timestamped and other timekeeping operations. This board implements the clock in a standard way for the RC2014. 

The design is largely based on the clock implementation on the [RetroBrew Computers SBC V2](https://retrobrewcomputers.org/doku.php?id=boards:sbc:sbc_v2:start) and [Zeta SBC V2](http://www.malinov.com/Home/sergeys-projects/zeta-sbc-v2).

## What can you use this for?

Telling the time :)

## Getting started with RomWBW

Set ```DSRTCENABLE``` to true in the configuration and rebuild your ROM image.

On startup you will see the time shown.

![Boot](./boot.png?raw=true)

ZSystem has more complete support for time utilities than CP/M. After booting into ZSystem by pressing Z, Run ```ldds``` to load the resident time driver. ```td``` can then be used to set the time as well as view it.

In CP/M ```RTC.com``` can be used for querying and setting the clock but it is very basic.

## Jumpers

SW1 - Address configuration. For the default address of 0xC0, set switches 5 and 6 to on.

## Bill Of Materials

Reference| Value|Farnell part no|Rapid part no|Digi-key part no|

---------|------|---------------|-------------|----------------|

P1|1x39 right angled pin header|||732-5350-ND|

BT1|Keystone 106 20mm battery holder for CR2032|1650672||36-106-ND|

BT1|CR2032 battery|||P189-ND|

U1|CD74HCT688E COMPARATOR, SINGLE, PDIP-20|2407104||296-2131-5-ND|

U2|SN74HCT125N LOGIC, BUS BUFF TRI-ST QD, 14DIP|1739676||296-8386-5-ND|

U3|CD74HCT174E 74HCT CMOS, 74HCT174, DIP16, 5.5V|1105983||296-2100-5-ND|

U4|DS1302N+ RTC W/ RAM, 248B, D-D-M-Y, HH:MM:SS, DIP|2515367||DS1302N+-ND|

U5|SN74HCT32N IC, QUAD 2-INPUT OR, 74HCT32, DIP14|9591982||296-1615-5-ND|

C1-5|0.1uF MLCC capacitor|||BC2665CT-ND|

Y1|32.768 kHz crystal|9712887||535-9034-ND|

RN1|10k 8 Pin Commoned Resistor Network||63-0125|4608X-1-103LF-ND|

SW1|6 way DIL switch||80-0338|CT2066-ND|

U1|CONN IC DIP SOCKET 20POS TIN|||AE10015-ND|

U2|CONN IC DIP SOCKET 14POS TIN|||AE10012-ND|

U3|CONN IC DIP SOCKET 16POS TIN|||AE10013-ND|

U4|CONN IC DIP SOCKET 8POS TIN|||AE10011-ND|

U5|CONN IC DIP SOCKET 14POS TIN|||AE10012-ND|

## Construction tips

The footprint for the battery holder is designed for a Keystone 106, other battery holders should work if the pins are ~20.5mm apart, which seems to be fairly standard.