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The ordered switching power supply arrived today. Its actually rated a 5V 10A, and it seems to run both 527 RAM cards fine.
I ran some memory test on the second 527 card and ultimate found 2 more dead 2114's which I replaced.
So good news, I now have a full compliment of 48K up and running.

Hi, me again, So I'm looking for someone who may have a spare A13 floppy board. I'm looking to hook up a floppy drive to my C24P sometime in the near future so I'm guessing I'll need one of these boards. (Having never seen an A13 board before, it's hard to imagine what the board exactly comprises of...

Today I upgraded the serial to 9600 Baud. One trace cut and a jumper later I now have a super fast connection and I can load SuperDefender in less than 15 seconds. Unfortunately when I was removing the 505B board a pin broke on one of the connectors that connect to the back plane. Fortunately I had ...

Bad RAM found! first I switched around A7 and B7 and I started getting errors at 4400 instead of 441B. Eureka! I then swapped out the 2114 at A7 (formerly B7) for a known good one and so far it seems to be working well. I'm just running through the RAM test program a few times just to be sure. Finge...

Oops, my bad. I was meant to type 527, not 427. I blame my fat fingers. Thanks for the reply. It's very informative and certainly help me understand how the RAM is addressed. I didn't imagine they were in pairs like that. I have reinserted, and even totally removed E7 and F7, however the problem sti...

Just another quick update. I have been testing the memory and these are the locations that seem to error out: 441B 443B 449B 44BB 451B 453B 459B 45BB 461B 463B 469B 46BB 471B 473B 479B 47BB Before 441B and after 47BB the memory tests ok. Seems like a fairly consistent pattern in what address are scr...

Yes. I think I'm definitely going to build a data separator sometime in the future. I've even got my eye on a Shugart SA-400 drive for the machine. I've had a look at the article and it doesn't look too hard to build, but for now I just want to play with BASIC for a bit, and changing out the EPROM s...

Although I have contemplated doing the 2716 mod multiple times over the past 3 days, I have restrained myself. As you say, the machine is working now, and I don't really want to mess with it too much especially seeing as the area in question has already had some serous hacking done to it... I'm goin...

Just a quick reply before I head off to work. Firstly, thanks for all the great info. That makes perfect sense now. ...Look what I just found. http://www.go4retro.com/wp-content/uploads/2011/10/IMG_3076.jpg Seems Jim Brain has literally just finished a limited production of 23xx adaptors, how timely...

Hi Dave, Thanks for the reply. I was thinking my issue was a simple one, but it seems to be a little more complex than I expected. I had to re-read your response 3 times before I understood it. I do have a second 527 board that when installed gives my weird graphics, however I believe that is a powe...