Atari 130XE

How the 128 KB memory works

The 6502 addresses 64 KB at a time. The 130XE therefore divides its extra 64 KB into four banks selected through PORTB. The selected bank appears in the 16 KB window at $4000–$7FFF.

The CPU and ANTIC can independently access base or extended memory. This can separate program data from display data, for example. The program must switch memory banks itself.

Uses for the extra memory

A program written for 64 KB runs on the 130XE as before; more memory does not automatically provide more space for an Atari BASIC listing. Programs with bank-switching support can use the extra RAM.

Another use is a RAM disk. DOS 2.5 creates one with RAMDISK.COM. RAM disk files disappear when power is switched off, so they must be copied to permanent storage before finishing.

ECI and SIO devices

ECI adds bus signals alongside the cartridge slot. Devices designed for the XL series' PBI require an adapter for this pair of connectors.

Disk drives, cassette recorders and printers still use SIO. The computer also has two controller ports and monitor and RF outputs. Power supply selection must account for the 130XE's higher current consumption and any connected upgrades.

How the 128 KB memory works

Uses for the extra memory

ECI and SIO devices

Sources and further reading