Editing Commodore 128 (section)

== Memory and Storage ==

The C128 features a substantial memory upgrade over its predecessor. Memory was enlarged to 128 KB of RAM in two 64 KB banks<ref>{{cite web |url=https://en.wikipedia.org/wiki/Commodore_128 |title=Commodore 128 - Wikipedia |publisher=Wikipedia |date=2025-06-06 |access-date=2025-06-09}}</ref>. From this, 38,911 or 122,365 Bytes are free for use under BASIC<ref>{{cite web |url=https://www.c64-wiki.com/wiki/Commodore_128 |title=Commodore 128 - C64-Wiki |publisher=C64-Wiki |date=2019-10-27 |access-date=2025-06-09}}</ref>.

The C128's RAM is expandable from the standard 128 KB to 256, 512 or even 1,024 KB, either by using commercial memory expansion modules, or by making one based on schematics available on the internet<ref>{{cite web |url=https://en.wikipedia.org/wiki/Commodore_128 |title=Commodore 128 - Wikipedia |publisher=Wikipedia |date=2025-06-06 |access-date=2025-06-09}}</ref>. Commodore's RAM Expansion Units use an external 8726 DMA controller to transfer data between the C128's RAM and the RAM in the expansion unit<ref>{{cite web |url=https://en.wikipedia.org/wiki/Commodore_128 |title=Commodore 128 - Wikipedia |publisher=Wikipedia |date=2025-06-06 |access-date=2025-06-09}}</ref>.

The C128's complex architecture includes four differently accessed kinds of RAM (128 KB main RAM, 16–64 KB VDC video RAM, 2 kNibbles VIC-II Color RAM, 2-KB floppy-drive RAM on C128Ds, 0, 128 or 512 KB REU RAM)<ref>{{cite web |url=https://en.wikipedia.org/wiki/Commodore_128 |title=Commodore 128 - Wikipedia |publisher=Wikipedia |date=2025-06-06 |access-date=2025-06-09}}</ref>.