FYI.... status update....
Found an issue with the modified circuit board I made. I had the "ACK" and "ACT" lines swapped. Oops! This was easy enough to fix with a cut/jump on the board though.
I was able to get the RaSCSI software running on a Raspberry Pi 4. My Quadra is able to see the virtual hard disk I created, as well as format, read and write to it. I ran a quick benchmark, and the performance seems to be on par with my SCSI2SD v5.
My current sticking point is with CD-ROMs. Using various SCSI tools, the Mac can see that there is a drive present at the correct SCSI ID, but it hasn't detected any of the images that i have "Inserted". So, I'm going to keep working that.
In the next few days, I'm hoping to run some benchmarks comparing the different versions of Rasperry Pis, and maybe on some different Mac models. But first, I'm trying to get the CD-ROM functionality working.
Ok thanks. I will give that one a try. I just bought a Macintosh Portable battery from that seller.
On a side note, I picked up this Macintosh Portable as not working, for cheap. When I got it, it looked brand new. The space bar is the same color as the other keys. No dirt at all inside or on the feet. I thought I would just try the new battery not expecting much and to my surprise it booted up just fine.
I'm pretty sure the board has not been recapped, but is likely pretty clean as I don't think this machine was used. My intention was to use this for writing because I love the keyboard, but it is in such good shape I feel like maybe I should not.
My question: Should I just preserve it like it is, maybe find one more beat up to use? If I use it maybe the board will go out or something or I will in some way damage it. This is my first vintage Mac aside from a G4 Cube.