C64 Dual Diag

Fig. 1: Retro Rewind Dual Diag

Two is better than one. The Retro Rewind Dual Diag cart provides you with a double headed Commodore 64 cartridge for all your diagnostic needs.

With our cartridge you get:

  • 586220++ Diagnostics - Updated with proper Kernal and SX-64 detection.
  • 781220 Dead Test - The ultimate tool to diagnose your dead C64.

This cart is a perfect replacement for both the single C64 Diag and Dead Test cartridges.

Compatible with the Commodore 64, 64C, SX-64 and C128 (in 64 mode only).

In order to take full advantage of the 586220++ diagnostics a full test harness is required.

781220 Dead Test

The Dead Test Diagnostic Cartridge is designed to test the C64 and C128/C128D (in C64 mode), even if your system fails to display video information on Power Up.

The Dead Test was used by Commodore technicians to assist in repairing dead PCBs.

The Dead Test is almost completely dedicated to System RAM testing and does no type of ROM, dedicated IC or Port Testing. For that you should use the 586220++ diagnostic side of the Dual Diag.


586220++ Diagnostics

The 586220 based diagnostic cart was used by Commodore technicians in house to diagnose problems with C64s.

When paired with a full test harness, the software exercises the CPU, system RAM, ROMs, dedicated ICs (SID, PLA, VIC, CIA, etc) and various I/O circuits of the C64. The test will report if something is bad and possibly display what IC has failed.

Refer to the manual below on proper operation and how to diagnose issues when using the 586220 cartridge.