As part of my repair series on the Europlus, the next step I'm taking to investigate the "screen full of question marks" is to ensure the ROMs are working, valid chips.

As before, I decided to use my TL866II to dump the ROMs, with suitable mapping of pins between the ROMs, and a similar ROM that t...

The Apple II Europlus uses 4116 type RAM ICs.

On my board, there were about 4 different manufacturers and speeds - obviously some have failed in the past and have been replaced. Without a booting machine however, how can I test that the RAM is working OK?

Thankfully, a circuit for testing 4164 I...

The Z80 softcard is somewhat of a curiosity. Released in 1980, it added a Z80 CPU to the Apple II, allowing CP/M (a popular business operating system) to be ran.

With CP/M gave the ability to run programs like WordStar, dBase, programming languages like PASCAL, and interactive adventures, such as...

I had previously programmed an ATmega328P using AVRDude - this was some time ago, and I was not even sure what program I had applied.

When I attempted to overwrite the program using the Arduino IDE, I hit a dead end. I got the error message:

stk500_recv(): programmer is not responding

It was c...

As part of the repair process for the Apple II Europlus, I have been testing each IC on the motherboard, to ensure it is working correctly. I have been able to test many of the 74 series ICs with my Xgemu 866 Universal Programmer, but there are some ICs that require more complex circuits to test tha...

These disks have been converted with c2t, and can be used in the same way as the Apple II Disk Server. Connect to the audio input of your Apple II, and at the basic ] prompt, type LOAD and press enter. Then play the chosen file below. The disk image will be written to a blank floppy, inser...