Editing Atari 260ST (section)

== Architecture ==

The 260ST uses the identical architecture as the [[Atari 520ST]], differing only in the amount of installed RAM:

* '''CPU:''' Motorola MC68000P8 (DIP-64) or MC68000FN8 (PLCC-68), running at 8.00 MHz
* '''Architecture:''' 16/32-bit (32-bit registers and ALU, 16-bit external data bus, 24-bit address bus)
* '''RAM:''' 256 KB, using 16× 64k×1 DRAM ICs in two 8-bit banks (vs. 16× 256k×1 on the 520ST)
* '''ROM:''' Early units: small boot ROM that loads TOS from floppy disk. Later units: 192 KB TOS 1.00 in 6× 32 KB mask ROMs
* '''Custom ICs:''' Shifter (C025914), GLUE (C025915), MMU (C025912), DMA controller (C025913) — identical to those used in the 520ST

=== Major ICs ===

<templatestyles src="Template:StyledTable/styles.css" />
{| class="wikitable"
! Function !! Part Number !! Notes
|-
| CPU || MC68000P8 / MC68000FN8 || 8 MHz, DIP-64 or PLCC-68
|-
| Video Shifter || C025914-38 || Pixel serialiser; reads DRAM and generates video output
|-
| GLUE || C025915-38A || Bus timing, address decode, video timing
|-
| MMU || C025912-38 || DRAM row/column multiplexer and refresh controller
|-
| DMA Controller || C025913-38 || ACSI hard disk and floppy DMA
|-
| FDC || WD1772-00-02 || Floppy disk controller, 250 kbit/s DD
|-
| MFP || MC68901 || Multi-function peripheral: timers, interrupts, UART
|-
| ACIA (×2) || MC6850 || Keyboard/IKBD (7812.5 baud) and MIDI (31.25 kbaud)
|-
| Sound/PIO || YM2149F || 3-voice PSG + parallel I/O ports
|-
| RS-232 drivers || MC1488 / MC1489 || Line-level conversion for serial port
|}