https://www.amazon.com/gp/product/B06Y4SWV1M
Although it comes with separate power wires to plug into a PC power supply, I found that it appears to accept +5v on pin 20 as well. This would make the power wire unnecessary so long as I moved the jrIDE jumper to provide +5v to that pin. I installed the DOM on the end of the jrIDE card (after a lot of online study to make absolutely sure I wouldn't get it upside down. Found plenty of IDE pinouts online, and confirmed things with continuity tests etc).
I then installed the jrIDE on the side of my PCjr's parallel port sidecar and started up the machine with a DOS boot diskette in A:.
After a screen with the IBM logo and color bar (reporting 640K), lines from the PCjr jrIDE BIOS appeared (reporting 112K base, 736K total memory). Then a couple of odd messages.
With the DOM installed but powered off, these lines appeared:
With the DOM installed and powered on, these lines appeared instead:Drive 0:Not installed.
Drive 1:Not installed.
So -- does this actually mean this DOM is a no-go? Or can I try to format drive(s) anyway? I tried powering it both through pin 20 and through its separate power wires, and got the same results whenever it was powered on.Drive 0:
Error! This drive is too old to support LBA access.
Drive 1:
Error! This drive is too old to support LBA access.
And also, just for my information -- I'm not clear on why two drives, 0 and 1, are mentioned. Does the jrIDE BIOS define two drives as existing there?