With the release of V1.0 of the Aquarius⁺ firmware, the system supports hardware that does not have a physical Z80 installed. This is useful if you are unable to acquire a Z80 CPU of the proper speed and footprint, now that Zilog no longer manufactures the chip. Note that this is an OPTIONAL fix for users with hardware Z80s installed.

• Aquarius⁺ Standard - rev2
• Aquarius⁺ Mini - rev0

1. Install V1.0 or later of the Aquarius⁺ firmware, using the RUN "ESP:SETTINGS" and then either the update or updategh method. If your hardware has not yet been flashed/updated (self-manufactured devices), follow the installation instructions in the firmware download. After updating, reboot and ensure V1.0 or later of the OS (not plusBASIC) has been installed by looking at the top of the start screen.

2. Turn OFF your Aquarius⁺ and remove all cables and connected devices. Also remove your SD card.

3. Open your Aquarius⁺ by carefully removing the four Phillips-head screws on the bottom of the case. Do so in a clean, antistatic environment where you have room to work.

Note that the Aquarius⁺ Mini version will look slightly different from the image below.

4. Remove the PCB from the case and locate the FPGA Spare IO header (J10). Using a soldering iron and a small bit of solder, you will be installing a standard 1x2 header in the left-most two pins. Soldering is done from the BACK side of the PCB, not the front. You may need to use putty to temporarily hold the header in place on the front of the PCB while soldering from the back. Clean up any flux or solder splatter after you are done.

5. Install a 1x2 jumper across the two header pins. This tells the FPGA that the system is running WITHOUT a Z80 CPU installed (even if one is installed), and it will force the system to use ONLY the T80 software core. The jumper can be removed at any time, if you want to have the option of using the hardware Z80.

6. Reinstall the PCB in the Aquarius⁺ case, taking care when putting the screws back in place to not overtighten them. The plastic resin of the case is strong, but threads can strip out if too much force is used.

7. Reconnect all cables and insert the SD card, and test your Aquarius⁺ by navigating the contents of the folders. Note that the old RUN "ESP:SETTINGS" command no longer works. You must now type CTRL + TAB to bring up the Settings overlay. If installed properly there should NOT be an option for Use external Z80 listed.

Again, a reminder that this is not a required update for most users. Even without the jumper installed, the updated Settings overlay can turn on or off the use of an installed Z80 CPU.