I found the Back to the Garage book at my university's library, and I went about building a Replica 1 myself, sourcing the parts from Mouser and JLCPCB using the CAD files from the book.
I've built everything and the connections look good, but I still need to program the ATMEGA8 for video. Issue is, there's got to be a missing include file or something in the firmware source provided here. I've scoured the internet looking for a reason why, but "i2cstat" isn't a named register or anything, the asm file doesn't define it, and I'm not sure what register it's supposed to be. There were a couple other, minor, errors in the video asm file, but the others assembled no problem using Microchip (Atmel) Studio 7.
I figured it'd be easier to ask someone with one of the older Replica 1's (I think revision C, as long as it uses the ATMEGA8 for composite video).
Could someone here grab the binary off their working ATMEGA8 and send it my way? I'd really appreciate it, as it's all I need to get this guy working!
Vince Briel is a regular on the Apple II Enthusiuasts Facebook page.
Why not ask him directly?