For Sale New type of C128 VDC 64k expansion

Ah, so your sandwich board replaces the need for those two on-board RAM chips? If so, then that's fantastic, as I believe that I have one of those RAM chips that is bad (I am getting garbage characters on screen, it's terrible). Your board will save me the trouble of de-soldering and replacing those hard-to-find RAM chips.

Please let me know when you're able to start shipping again. I definitely have a need for your board!

Nope, just pull the video chip, plug the board in, and plug the video chip into the board. Very simple and reversible.
I notice on your photos the two 41464 DRAMs are on sockets. You can now completely remove them to reduce heat and power consumption.
 
Ah, so your sandwich board replaces the need for those two on-board RAM chips? If so, then that's fantastic, as I believe that I have one of those RAM chips that is bad (I am getting garbage characters on screen, it's terrible). Your board will save me the trouble of de-soldering and replacing those hard-to-find RAM chips.

Please let me know when you're able to start shipping again. I definitely have a need for your board!
I have 2 in stock I can ship immediately but I have a small box problem.

Also, if one of your DRAM problem is bad then they must be removed as they could cause short circuits on the DRAM control/data lines. Since they don't need to be salvaged, there is no need to desolder them, you can remove them 'destructively'.

I'll send you a PM.
 
I'm not sure if the existing chips are "bad" in the sense that they're short-circuiting destructively, just not functioning properly enough to store data properly (hence the garbage). I can still see the cursor on screen, and am able to type and see Basic responses, it's just that a good portion of characters are malformed, and there are other random characters distributed across the range of the screen. If the RAM on your board avoids addressing those existing chips (by being upstream and closer to the VDC) then I might not have to remove the existing two RAM chips. But, if I have to do so I reckon I will.

I have 2 in stock I can ship immediately but I have a small box problem.

Also, if one of your DRAM problem is bad then they must be removed as they could cause short circuits on the DRAM control/data lines. Since they don't need to be salvaged, there is no need to desolder them, you can remove them 'destructively'.

I'll send you a PM.
 
I'm not sure if the existing chips are "bad" in the sense that they're short-circuiting destructively, just not functioning properly enough to store data properly (hence the garbage). I can still see the cursor on screen, and am able to type and see Basic responses, it's just that a good portion of characters are malformed, and there are other random characters distributed across the range of the screen. If the RAM on your board avoids addressing those existing chips (by being upstream and closer to the VDC) then I might not have to remove the existing two RAM chips. But, if I have to do so I reckon I will.
I see wishful thinking on a massive scale in your comment. It's impossible not to address the onboard DRAM, only their response is cut off (8 pins cut). Considering the behavior of the DRAM on your C128's VDC, I consider it is unsafe to leave them. There is no telling how they can wreck havoc with the address lines and the CAS, RAS control signals.
Not 'addressing' the onboard DRAM would leave their control lines floating and there is no telling what nonsense they would do. By leaving them connected, the onboard DRAM still receives data and refresh cycles from the VDC but their response is ignored and that's just fine when they are properly working but that's clearly not the case with your machine.
 
It was just a shot in the dark, but now realize that there's a pass-through to the existing RAM on the motherboard. No matter, I'll snip the old RAM off the motherboard.

PM'd with a quantity request.


Edit: Payment sent.
 
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Would like to order 1 SaRuMan-VDC 64k expansion board for the C128. Do you have any left in stock?
 
Mine finally arrived, very well-packed! Gotta love the speedy postal service, lol.

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