Re: colors in dos
- Posted by useless_ Jun 25, 2013
- 1688 views
I contend that, unlike the process of getting a Pi to work with an SID, it is not possible to find information on adding 2GB of ram to a C64 online from the web, as you implied:
OTOH, I have yet to see a manual that describes how to set up a Commodore 64 to use 2GB of RAM. I guess some kinds of versatile simply can't be covered in a manual.
Today, you have to get on the web for this kind of information.
Remember how i memory mapped 74LS163's on the external buss? What if i mapped four 74LVC574 (or some other latch) out there, and made a variable called EA (for external address), and i put the binary value of 2^30 into EA? Then on the other side of those 74LVC574 i attached 2GB of memory in whatever flavor i had handy, along with a few chips such that the last write into EA caused a rear or a write cycle (my choice) to occur on the ram? Lets say i had some space allocated in the memory map, and when i read or wrote there, it was picked off by the card holding my 2GB of ram, and used in that read or write cycle i mentioned? Gosh, that's just about how it can be done! And you know what else? I'll give you a freebie: the SID chip addresses are not fully decoded, you can decode those, use one block for those EA addresses, one for indexes, one for misc processing, one for transparent reads and one for writes, <!presto!> you have not taken out any ram inside the C64 to interface 2GB thru.
There, now that i have posted this, you can find it on the web.
useless
