> Bit of a tangent but the Apple II used a similar approach for its video system. A lot of home computers did. The ZX Spectrum has the same weirdass screen lay

> Bit of a tangent but the Apple II used a similar approach for its video system. A lot of home computers did. The ZX Spectrum has the same weirdass screen layout as Apple II HGR, for much the same reason - the screen is scanned in 256-byte (32 bytes by eight rows) blocks so that you hit all the 256 byte pages with a refresh one after the other. It's kind of an odd choice because the Z80 could be set up to handle DRAM refresh by itself, but the 6502 did not have that luxury.