Articles tagged “DS1307”
Booting CP/M 3 from an SD card
Up to this point I have been running CP/M 2.2 on the Z80 computer. CP/M 3 adds a number of useful features, including the following:
Support for more than 64KB RAM via banked memory. Standardised access to real-time clock for file date and time stamping.Improved text entry on the command-line when using the memory-banked version, such as the ability to move the cursor when editing and recall the previously entered line.Support for disks with physical sectors larger than the default record size of 128 bytes.
Comments ATmega644P AVR CP/M DS1307 Electronics SD card Z80 Z80 computer
Times, backlights and off-page calls
Dates, times and backlights
I'm using a DS1307 real-time clock to provide the computer with real-time date and time functions. It's a great little chip - all it needs is power, two lines for I2C communications, a 32768Hz crystal between two pins and a back-up battery to keep it ticking when main power is removed and it's happy. That accounts for seven pins; the last remaining pin can be used as a one-bit output (you can set it to a high or low state in software) or it can be configured to output a square wave at 1Hz, ~4kHz, ~8kHz or ~32kHz.