Atari 5200

Chip Info

CA018087 (4-Port Original)

• VR1, VR2: +5V Regulator: 7805
• U1: 4050 (CPU & Antic /RESET, Video Buffer)
• U2: CPU: CO14806 (6502C-based)
• U3: ANTIC: CO12296
• U4: LS244
• U5: GTIA: CO14805
• U6: 74LS139 (Address decoder)
• U7: POKEY: CO12294
• U8: ROM: CO19156A
• U9-U13: 4052 (Keypad multiplexers)
• U14: LS10
• U15: LS244
• U16, U17: 74LS258 (DRAM address multiplexer)
• U18-U25: RAM: 4516
• U27: 74LS00
• U28: LS10
• U29: 4013 (Power ON/OFF latch)

CA020108 (4-Port "Universal")

• VR1, VR2: +5V Regulator: 7805
• A1: 4050 (CPU & Antic /RESET, Video Buffer)
• A2: CPU: CO14806 (6502C-based)
• A3: ANTIC: CO12296
• A4: Removed
• A5: GTIA: CO14805
• A6: 74LS139 (Address decoder)
• A7: POKEY: CO12294
• A8: ROM: CO19156A
• A9-A13: 4052 (Keypad multiplexers)
• A14: 74LS125
• A15: 74LS51
• A16, A17: 74LS258 (DRAM address multiplexer)
• A18-A25: RAM: 4516
• A26: 4013 (Power ON/OFF latch)
• A27: 74LS00
• A28: Removed

CA021374 (2-Port)

• VR1, VR2: +5V Regulator: 7805
• A1: 4050 (CPU & Antic /RESET, Video Buffer)
• A2: CPU: CO14806 (6502C-based)
• A3: ANTIC: CO12296
• A4: Removed
• A5: GTIA: CO14805
• A6: 74LS139 (Address decoder)
• A7: POKEY: CO12294
• A8: ROM: CO19156A
• A9-A11: 4052 (Keypad multiplexers)
• A14: 74LS125
• A15: 74LS51
• A16, A17: 74LS258 (DRAM address multiplexer)
• A18-A25: RAM: 4516
• A26: 4013 (Power ON/OFF latch)
• A27: 74LS00
• A28: Removed

IC functions provided by the 5200 FAQ [1]

Schematics

5200 4-Port Schematics - CA018087 (4-Port Original)

This appear to be for the original release 4-port model as the modification for the VCS adapter is not shown.

• 
  Schematic A: CPU, Pokey, Antic, GTIA
• 
  Schematic B: RAM
• 
  Schematic C: Controller Ports, Power, Output

5200 4-Port Schematics - CA020108 (4-Port "Universal")

These schematics show a modified pin 24 on the cartridge port and are probably from the * model 4-port 5200.

• 
  Schematic 1: Controller Ports
• 
  Schematic 2: Power & Video
• 
  Schematic 3: CPU, Pokey, Antic, GTIA
• 
  Schematic 4: RAM

5200 2-Port Schematics - CA021374 (2-Port)

• 
  Schematic 1: Controller Ports
• 
  Schematic 2: CPU, Pokey, Antic, GTIA
• 
  Schematic 3: RAM
• 
  Schematic 4: Video
• 
  Schematic 5: Power

Controller / Keypad / Trackball Schematics

• 
  CX52 Controller
• 
  CX53 Trakball: X-Y Encoders
• 
  CX53 Trakball: Keypads

Capacitor List

Purchase these parts as a kit

Four port: CA018087

C45	4700uF	25v

Four port: CA020108 and Two port: CA021374

C45	47uF	25v

Other caps for consideration

Styrene audio circuit caps which occasionally fail. Optional MLCC caps are included in our 5200 kits.

C13	820pF	25v
C14	820pF	25v

Service Manual

• 
  Atari CX 5200 Field Service Manual

4-Port mod for VCS (2600) Adapter

Purchase these parts as a kit

C1: .1uf ceramic
R1: 1k
R2: 1k
R3: 3.3k
D1-5: 1n914

Download the Atari 5200 VCS Adapter Modification manual.

4-Port Switchbox Elimination Modification

The special switchbox used on 4-port Atari 5200 units is unique to the console and can be failure prone. With a simple modification the need for the switchbox can be bypassed and a conventional switchbox or direct fit adapter can be used. Similar modifications were performed by Atari service personnel in the 1980s, and instructions were posted at Atariage here and here

Theory

The console & switchbox send power and RF over the same cable. If the RF & power circuits are split, you can manually add a power jack and use a conventional switchbox.

History & Example Installs

https://atariage.com/forums/topic/17441-5200-4-port-power-mod-success/

https://atariage.com/forums/topic/20871-atari-5200-4-port-power-modification-warning-big/

Schematics

Purchase these parts as a kit

• 
  Original power circuit
• 
  Remove large capacitor C45 and coil L8. Drill and install DC jack.
• 
  Connect DC jack center post to diode (non band end. Connect band-end of diode to the positive terminal at C45. Solder 47uF cap in C45 location and .1uF cap across DC jack + and -
• 
  3-terminal DC jacks should have the wires connected as shown. These types of jacks have built-in switches for use in devices with both battery and DC connections. Soldering negative to both isn't electrically necessary but takes out the guesswork of which terminal is active when a plug is inserted.

Notes

Diode is for reverse-polarity protection and isn't strictly necessary

Original 4700uF can be used in place of 47uF but will need to be relocated and have it's leads extended.