[Duo2400] Re: Added VRAM in 2400c

[Tom and Lisa P]

>I no longer have the URL, as I saved the page as a PDF, in Safari. 
>It seemed like the best idea at the time, as the page was in 
>japanese, and I had to translate it through another web page. The 
>translation was incredibly rough, to say the least, but the photos 
>were good, so saving as PDF has enabled me plenty of time to figure 
>out the translation, at my own leisure. I'm more than happy to mail 
>the PDF, should anyone request it.

Please do.  I would like to see it.

>Just an update, tho, the guy I purchased my dead logic board from 
>sent me a 2300c, instead of a 2400c. I have no idea how similar the 
>pieces between the two are, but I'll check my AppleTech info, and 
>also the info on the VRAM chips to find out. if they're not 
>compatible, I'll have to either send the board back for an exchange, 
>or continue looking for a dead 2400, or even dead 3400, for parts. 
>BTW, anyone here happen to have one of those?

The 2300 and 2400 have totally different VRAM chips.  Get a refund.

>To finally get to my point ;-P.....I'm not sure how this hack would 
>apply to a 2300, tho I do seem to now have a board from one in my 
>possession. I will say however, from looking at the board, that 
>there doesn't seem to be room for added VRAM. The 2400 is based on 
>the 3400 logic board. The 3400 logic board has room for 2mb of VRAM, 
>only half of which is installed on the 2400, leaving room to add 
>more.
>
>-Antonio

To get more VRAM on a 2300 you would have to piggyback the extra VRAM 
and run address lines to the correct pins on a transplanted 65225 
video controller.  The 65225 is pin compatable with the 65220 (I know 
because I have done this on a Duo 270c), but I havnt gotten around to 
adding the VRAM yet.

The 3400 does not have room for more VRAM.  There are no open pads 
like the 2400 has.  The 3500 might have 2 MB of VRAM, but the only 
3500 board I have is dead, so I cant be sure.

Mad Dog