Atari Mega ST Service Manual

The Mega Service Manual is Atari Corporation's service manual for the Mega 2 and Mega 4, sold as the Atari Mega ST2 and Mega ST4. It is undated; its drawings carry dates from 1986 and 1987. The scan has 90 pages with a text layer.

Contents

With the printed page numbers:

• Section 1, Introduction: main components, case design (figure 2 on p. 1.2 shows the battery compartment), differences from the 520ST/1040ST (p. 1.5)
• Section 2, Theory of operation: Glue, memory (1 Mbit × 1 DRAMs, 16 per bank), DMA, MFP, Shifter, Blitter, the RP5C15 real-time clock with its 3 V battery backup (p. 2.7), and the monitor, MIDI, mouse/joystick, printer, RS-232, floppy and hard disk port pinouts (pp. 2.8 to 2.14)
• Section 3, Testing: dead-unit procedure (pp. 3.2 to 3.3), the Mega/ST diagnostic cartridge revision 4.0 with every test and error code (pp. 3.4 to 3.19)
• Section 4, Disassembly and reassembly (pp. 4.1 to 4.3)
• Section 5, Symptom checklist (pp. 5.1 to 5.2)
• Section 6, Diagnostic flowcharts
• Section 7, Parts list (main board capacitors, resistors, crystals, connectors and ICs with Atari part numbers and locations) and assembly drawings
• Section 8, Schematics and silkscreen: main board PCB C100167 Rev 5.0 (assembly CA200019), the ASP34-1 power supply schematic and wiring, and test-fixture drawings
• Section 9, Glossary

What this document does not contain

• The main board schematic sheets are low-resolution and hard to read.
• The power supply has a schematic but no separate parts list.
• The later Mega 1 is not covered.

Pages that cite this document

• Atari Mega ST: cites Section 1, pp. 1.1–1.5, Section 8, PDF pp. 71–81, Section 7
• Atari Mega ST Capacitor Replacement Guide: cites Section 7, PDF p. 62, Section 8, PDF p. 73, Sheet 5
• Atari Mega ST General Maintenance: cites Section 6, p. 6.1, Section 4, pp. 4.1–4.3, Section 2
• Atari Mega ST Troubleshooting Guide: cites Section 3, pp. 3.1–3.19, pp. 3.2–3.3, pp. 3.4–3.17, pp. 3.18–3.19

Download: Atari Mega ST Service Manual.pdf