It's time for a new "module", the Virtual Disk Module! In the photo is that one on the right, near the previous GPIO module.

In the File section is possible see the simple schematic A110417.pdf with two I2C EEPROM 24LC1025.

With this module it is possible to emulate two disks of 128kB each (probably like the floppy disk drives of those years).

Each disk is divided into 32 tracks of 32 sectors. Each sector is 128 bytes long.

Of course to manage this new HW there is a new release of IOS. The new file S221116_R180217_Z80.ino is in the File section.

This new IOS checks if the module is present and prints a message if found:

There is also a new item in the boot selection menu if the virtual disk is found, to use the User led as a disk activity led:

I suggest to activate this option to have an idea of the behavior.

ViDiT

In the File section I've added a simple test program (file "ViDiT - S090417.c") to check the virtual disk. Of course you need to compile it with the C "toolchain":

About I2C speed

With this IOS the I2C speed is 200KHz. Note that if you are using a 16MHz external quartz to clock the Atmega32 the I2C speed will be 400kHz. In this case I suggest to lower the two 4k7 pull-up resistors (on SDA and SCL signals) to about 2k2.

The next Log will bring the CP/M 2.2 up and running...