Commodore 128 Diagnostic Instruction and Troubleshooting Manual (314060)
The C128 Diagnostic Instruction and Troubleshooting Manual, Assembly #314060-01/02 is Commodore's manual for its Commodore 128 diagnostic kit, copyright 1986. The scan has 42 PDF pages with an OCR text layer. Assembly 314060-01 is the complete kit (diagnostic cartridge, user port hardware adapter, keyboard connector PCB, cable harness and serial port connector); 314060-02 is the add-on kit without the user port adapter and cable harness, which are the same parts as in Commodore's C64 diagnostic kit (section 1.1).
Contents
[edit | edit source]Section 1, operation and test instructions (printed pp. 1-1 to 1-9): unpacking, basic diagnostic theory, installation, start-up, and the tests in order: zero page, stack page, screen RAM, colour RAM, high and low RAM, the system ROMs, PLA, cassette port, keyboard, control ports, serial port, user port, timers, interrupts, sound, and the lower screen display.
Section 2, C128 system troubleshooting (pp. 2-1 to 2-18): basic preliminary checks, power supply, reset, clocks, video, system RAM with a memory organisation overview, the Z80, the 8502, the data and address bus, the 8564 VIC, the 8721 PLA, the 8722 MMU, the 8563 VDC and the 6526 CIAs.
Section 3, diagnostic symptoms (pp. 3-1 to 3-8): diagnostic errors displayed, incorrect 40-column screen, intermittent boot or lock-up, incorrect 80-column screen.
What it settles
[edit | edit source]- How the cartridge starts: it sits at $8000-$9D5F and the C128 runs it when $8006-$8009 contain "CBM" (section 1.2).
- The preliminary checks, all with the cartridge fitted and to a ±10 % tolerance: +5 V at pin 25 and +12 V at pin 28 of the SID (U5); RESET at pin 40 of the 8502 (U6) low at power-up and rising to +5 V within a second; 14.3 MHz, 8.18 MHz, 1 MHz, 2 MHz and 4 MHz clocks at the 8564 VIC (U21) and 16 MHz at the VDC (U22) (section 2.1). The clock figures are for the NTSC machine.
- Where to trace a missing rail: the + leg of C107 for +5 V, then C99, switch S1, filter L5 and connector CN11; the + leg of C111 for +12 V, about +18 V unregulated at the anode of CR10 ahead of regulator U59, and 9 V AC at the inputs of bridge CR13 (section 2.2).
- The reset timing: C91 and CR15 on one half of the reset timer and C92 and CR16 on the other (section 2.3).
- Tables that map a failing test, or a particular wrong screen in 40-column or 80-column mode, to the signal and chip to check (section 3).
What it does not contain
[edit | edit source]- Component values or parts lists; see the service manual.
- The power supply's internal circuit.
- PAL clock figures.
Pages that cite this document
[edit | edit source]
Download: Commodore C128 Diagnostic Instruction and Troubleshooting Manual 314060-01-02 (1986).pdf (40 MB)