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New PCjr user...well, not really

PostPosted: Sat Sep 14, 2019 9:30 pm
by rhodyne
The wife bought me a PCjr shortly after we married - almost 27 years ago.
IBM PCjr base
PCjr monitor
PCjr wireless keyboard (revised)
IBM 128kb Memory Expansion
IBM Power Expansion
Unlabeled Parallel Port sidecar
IBM ProPrinter
Basic cart

Also have the original power brick but not the power expansion cord.
They've been in the attic for +20 years. Haven't tossed it because the sentimental value.

So I decided to pull it down and see what can be done. Needs a cleaning inside and out. Have to check the caps out before powerup, maybe recap some, and see if I can find one or more boot disks.
I've seen lots of tweaks and mods that weren't available when it was parked. Assuming I can get this thing in operation, I'm interested in mods like the 128k to 512k (or better) upgrade on the memory sidecar, NEC V20 or the jr-IDE card - too bad he stopped selling.

Open to most suggestions so please point me in the direction of any information that may help.

Re: New PCjr user...well, not really

PostPosted: Sun Sep 15, 2019 2:20 pm
by Chuckphd53
Good luck, keep us posted..
chuck

Re: New PCjr user...well, not really

PostPosted: Sun Sep 15, 2019 9:20 pm
by Brutman
The power expansion sidecar just uses another brick. The bricks are getting harder to find but they are not critical anymore now that the ATX hack exists. Alan also has some beautiful internal power cards he was making, but I'm not sure if he's taking a break from those too.

Modifying the 128KB sidecard to 512KB is supposed to be fairly easy; I've never done it myself though. There is a bit of desoldering involved. You might want to start looking for a supply of 256KB DRAMs. The NEC V20 gives you a modest speed bump (a few percent) but it also enables a few new instructions that help some later software that require a 80286 to run. (These are real mode instructions that the 286 added; the V20 has a few of them implemented.) I like parallel ports because you can connect Zip drives, Xircom Ethernet adapters, and all sorts of fun things to them.

Peruse the site for other ideas and enjoy!