Mike's PCjr Page

Hi dudes, Let me start with a few precisions about my setup. First, my keyboard is wired. Second, the switch on my Drive Two is in the "jr" position. Third, to power the Xircom adapter, I use a universal wall wart rated for 1A, which I set to 12VDC, positive center. When the adapter is pow...

Still not working. :( Hardware: IBM PCjr computer w/ V20 CPU 512K RAM (64+64+384) PCjr keyboard (wired) Racore Drive Two Enhancement Package Xircom PE3-10BT Ethernet adapter Straight through Ethernet cable 2Wire ADSL+ modem/router Software: MS-DOS 6.22 JRCONFIG 2.14 DOSKEY PE3PD 3.08 mTCP tools, Apr...

Got my Xircom PE3-10BT Ethernet adapter the other day. Read Mike's DOS networking pages. Found the packet driver for the PE3-10BT (PE3PD.COM). Set up Internet Connection Sharing on my Windows XP box (which has two network adapters) in order to have a DHCP server running on the unused adapter. Connec...

Hi all, I have a Racore Drive II and I've been looking for a way to render its parallel port bidirectional. Here's how you can do it: First, you have to unsolder the 74LS273 chip that is near the DB25 connector (don't confuse this chip with the 74HC273 that is near the top edge of the board). Since ...

It looks like we don't have the same board. Mine has 6 banks of 64 KB, each bank being comprised of eight 64 kbit chips. It could be that 256 kbit chips didn't exist yet at the time this datasheet was written. However, I think I found the information I was looking for in the "PCjr Club Library&...

I found a datasheet too, but it's an abridged version. Yes, it "directly adresses 256KB without external devices", but this card has a few other chips on it, so I guess the designers managed to address 384K (added to the 128KB already installed in your Junior, you get 512KB). The datasheet...

The DRAM controller is a TMS4500A. I'd rather use the 4164 chips I already have. I know it would involve a little more than just piggybacking new chips on top of existing ones. I would have to bend some pins and run jumper wires. I've seen home computers upgraded that way. Well, I'll look into that....

Does anybody know if the Drive Two memory expansion card (w/ 384K) can be hacked in order to boost RAM to 640K or even 736K? I'm thinking about something like piggybacking 4164 chips or replacing them with 41256 ones. I already have a bunch a 4164 chips lying around.

Thanks,

Christian

Up and running now! Thank you guys!

Christian

Hi folks, I've made some progress, but I still have issues. Someone gave me a nice working 360K disk drive, which I installed in my modern PC. I now have a reliable way to write to 360K diskettes. Hurray! I also used Interlnk to establish a connection between my modern PC and my PCjr using a paralle...