Mike's PCjr Page

Really happy to see the jr-IDE that alanh sent me get here today. Many thanks to him for the fast ship!

I have some questions about getting started with it. I've looked at the jr-IDE pages here and on retrotronics.org and didn't see answers to these, but if I overlooked them my apologies in advance.

1) I went ahead and ordered the 16-GB DoM mentioned in another thread (https://www.amazon.com/Hotusi-Vertical- ... B078L8NLLZ), and it's supposed to be here tomorrow. I'm not seeing anything physical that will prevent me from inserting the DoM flipped upside-down on the IDE pins. Any help on which way it should go?

2) Is the CR2032 battery inserted the usual way in the holder (side marked with plus sign facing outwards and visible)?

3) Does it need any drivers, autoexec.bat/config.sys lines etc (besides rtc.com for the clock), or do I just insert the two items above, plug it into the side of the PCjr and turn it on?

4) The two-character alphanumeric display, which to my eye is on a part of the board that won't be visible once it's in a sidecar, is interesting. What's that for?

5) Any documentation on the various pins for jumpers or connectors, dip switches, etc?

Thanks much --

Both the jr-IDE and the DOM should have pin one marked. Just make sure you match them up.

Besides rtc.com you will want he memory manager I don't remember the name of it right now, but you need it for the jr to use all of the memory.

The coin cell battery goes in the normal way.

Enjoy you jr-IDE.

Thanks, Ken. Besides rtc.com for the clock, I also ran across jrconfig.sys and its doc file -- will check out those.

At this point I'm still not clear on a few points about using a DOM. Does it show up as a drive with a letter? What needs to happen on bootup to enable that? Also, do I need to reset a jumper to power the DoM? And can the jr be set to boot from the DOM, or does it always boot from floppy? I'll keep looking around, though.

The 2 digit display is a diagnostic tool.
It is to print out BIOS POST codes.
https://en.wikipedia.org/wiki/Power-on_self-test

See "progress and error reporting"

If your JR ever stops booting someday, you can find out what code it is hanging on and then using the technical reference manual, we can find out where to start looking for the problem.
----
The DOM is just a solid state hard drive, so it will require the normal hard drive initialization that any PC would require to make it a bootable device.
That is, you hook it up, boot to a DOS diskette, run fdisk, create a bootable partition, reboot the PC, boot to the floppy again and "format C:/s" the bootable partition.
From that point on, your ideJR+DOM will be a bootable device and the only time you'd need your floppy drive is to copy mountains of files onto all the DOM.

Hargle wrote:The 2 digit display is a diagnostic tool. ... The DOM is just a solid state hard drive, so it will require the normal hard drive initialization that any PC would require to make it a bootable device. ...

Thanks! Very clear now.