4164 vs. 4464 RAM chips

[airship]

At some time in its history, the C128 moved from using 4164 (65kx1) RAM chips to 4464 (8kx8bit) chips. I'm not sure when.



But this question arises: the 4164 was dynamic RAM, while the 4464 was static. As I understand it, the VIC-II is responsible for refreshing dynamic RAM. I assume there was a hardware change to the board to eliminate the refresh. But were any firmware changes required?

I'm sure you see where I'm going with this: did the VIC-II have less to do on later boards, and does that result in any performance enhancement?

[geneb]

Airship, the 4464 is a dynamic RAM chip just like the 4164, but only two are needed instead of the 8 to make a full bank.



g.

[airship]

So... all of the datasheets online that call this a STATIC RAM are wrong???

http://pdf1.alldatasheet.com/datasheet-pdf/view/107828/NEC/UPD4464C-12.html

It specifically says: 'requires no clock or refresh to operate'.

I'm confused.

[BigDumbDinosaur]

So... all of the datasheets online that call this a STATIC RAM are wrong???

http://pdf1.alldatasheet.com/datasheet-pdf/view/107828/NEC/UPD4464C-12.html

It specifically says: 'requires no clock or refresh to operate'.

I'm confused.

The plain 4464 used in the C-128 is a DRAM and requires refresh circuitry.  The NEC UPD4464C-12 (CMOS) part is static and is rated at 120 ns.  No, there is no advantage to using it in the 128.  But if you wanted to scratch-build your own 65xx-based computer the 4464C would be a good choice, since you wouldn't have to deal with refresh circuitry.

[airship]

See, I knew the problem had to be my own ignorance. As usual.

Thanks for the insight.