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Home Forums 68kMLA Designing a portable RAM card — #6
Post #6 by techknight
Source Forum68kMLA
CategoryHardware
Post DateSun, 5 Oct 2014 - 20:24
Original URLhttps://68kmla.org/bb/threads/designing-a-portable-ram-card.314/
Post
both. In theory, it should be universal. 

the difference between the two models, the Backlit has a Refresh line, whilst the original does not. And the backlit /AS becomes /RAMCS, meaning its stuck at a 5MB ceiling, which is why I will have a pin to allow a wire to branch off to the next slot to pick up /AS for the full 9MB. 

I will also have a DTACK pin as well, that will connect to the CPU DTACK line to allow the remaining 4MB of address space to be mapped to RAM without throwing bus errors. 

In a nutshell, if you want all 9MB, you will have 2 plug-in wires coming of the board going to the ROM slot. or maybe PDS. If you dont want wires, your stuck at 5MB. 

mp.ls