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I started working on fixing the 452C Keyboard. As all but the LM393 are socketed, and many of the IC's are the same I thought the simplest way to fix it was to but a few IC's (6 in total. I even managed to track down some 8T26's at Akihabara) and just replace each IC one at a time and test. If the r...

Just wondering if anyone here has the schematic for the 542C Keyboard?

Thanks

I can do one better than that. I can point you to Terry's (AKA Tezza. Yet another Kiwi) site, where you can find the MPI 51 manual. Maybe this would be great to link to from your site. http://www.classic-computers.org.nz/blog/2009-12-12-micro-peripherals-model-51-51-disk-drive.htm Terry is an avid c...

Picked up two bearings today and replaced the old ones. The difference is night and day. The mechanism is so quite now, and spins smooth with a nice whirr noise. Great!
Still have no idea if the drive actually works or not.

I have pulled the drive apart and pulled out the main spindle and bearings. Actually once I loosened the nut the unit spun pretty freely, but I have decided I will replace the bearings anyway as one bearing looks to be in a bad condition. It spins ok, but it may not have any grease left inside and i...

Hi again,
Did anyone happen to get a stash of these. I'd love to get a few spare ones just incase?

Cheers
Philip

I received a 23XX adaptor from Jim Brain today. I will burn a couple of EPROMs for testing sometime soon. Just wanted your opinion. As I don't know the order in what each 256k block should be in the EPROM, I was wondering if anyone knew what order that came install in the OSI masked ROM? The three p...

Great, I might install a 3.58Mhz Xtal tonight. Do I have to replace the 11.79648 Xtal for a 12mhz? Also, you mentioned that the keyboard was upgraded between the C2-4P's and the C4 . I have temporarily installed the C2-4P's keyboard in the C4, so hopefully there is no issue in doing this. I know the...

I'm still a little concerned about the drive, and of course still have not tested it with a OSI formatted disk. I have put in an unformatted disk and it seems to spin well, and came out no worse for ware. I did leave it spinning again (actually alway spins so I can't really avoid it) and after about...

In restoring my color Challenger 4p I noticed that, as far as I can tell, the only parts difference between the 540B video board in this machine and the 540B video board in my black and white C4-2P is the Xtals...all other parts seem to be installed. If I swap out the main 11.79648 Xtal for a 12mhz ...