Atari Jaguar CD

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Chip Info

  • U1: Power driver: TDA7073AT
  • U2: Digital servo processor: TDA1301T
  • U3: Digital servo processor: TDA1301T
  • U4: Data amplifier and laser supply: TDA1302T
  • U5: Voltage Regulator LM2941
  • U8: Digital decoding: SAA7345GP
  • U9: 500490 "Orbit", AKA Butch
  • U10: BIOS: 700066 (27c020)
    • Note: These are typically EPROMs, but I've had bad luck erasing & reprogramming them. If you want to do a BIOS swap, consider purchasing new chip or a clean pull.
  • U12: Serial EEPROM: IS93C46P
  • U13: Voltage Regulator LM2941

Reference Pictures

Common Problems

Boots to zooming Jaguar logo followed by red screen
Boots to graphic showing back of CD module power connector
Won't run cartridge software
Jag CD A/C adapter or connector is disconnected or defective
The Jag CD has 2 female cartridge ports, and one connecting card. The bottom of the connecting card connects to the Jaguar console, the other side connects to a female port inside of the Jag CD, and the main cartridge port is on top. If any one of these are dirty or damaged, the Jag CD will not operate correctly. See Jaguar common problems for notes on cleaning / inspecting cartridge & cartridge ports.
Icon with question mark (?) over CD appears. Can see CD spinning through CD door window.
System cannot read the CD. Defective or dirty laser.
CD is an older unsigned homebrew and requires a bypass cartridge or modified BIOS. See note below
Icon with question mark (?) over CD appears. CD doesn't ever spin up.
Check that the CD motor hub spins freely. Sometimes these can get pressed down and lock up the mechanism
Check that the lid switch mechanism is in place and assembled correctly. See reference pics above.
System cannot read the CD. Defective or dirty laser.


Capacitor List

Purchase these parts as a kit

Jaguar CD, rev C
C8	47uf	25v
C10	22uf	25v
C12	22uf	16v
C21	22uf	25v
C23	33uf	10v
C24	33uf	10v
C35	47uf	10v
C36	47uf	10v
C39	47uf	25v
C42	1uf	50v
C47	1uf	50v
C48	4.7uf	50v
C54	4.7uf	50v
C58	1uf	50v
C59	47uf	10v
C73	10uf	25v

The BIOS and homebrew titles

Many original homebrew games required the use of a bypass cartridge or game with built-in bypass routines, such as Protector SE or Battlesphere Gold.

The routines to properly sign homebrew software are now available, allowing the boot of homebrew software on unmodified Jaguar CD consoles, but older original titles still need a bypass option.

If you don't have access to a bypass cart, replacing the stock BIOS with a 27c020 programmed with an altered BIOS will allow booting of all software. A kit to replace the factory BIOS is available here. If you have a burner, the BIOS image may be downloaded from this page.