Atari problem solving
6 June 2020
Game Boy Color
6 June 2020
Commodore
VIC20 / 64
If you are lucky enough to still have these memorabilia in working condition (they just gave me one!) And you are also lucky enough to still have a TV with an RF card (antenna), the channel to use these devices in PAL format is 36. - in detail:
| Code: |
|---|
| UHF Band IV |
| Channel Width: 590-598 MHz |
| Channel 36 |
| Carrier: 591.25 MHz |
In practice, turn on the Commodore, turn on the TV, set the TV / Antenna input as the input and do the automatic channel search: at 591.25 it will find the signal! If you have a Commodore NTSC the frequency will be VHF 174 or 230 MHz depending on the channel set on the RF modulator.
If you don't like the RF module and don't want to waste time on its "features", you can always buy an RCA cable:
Aaaahhhhh… 3.5K of RAM (of 5 total) ……
C16 POWER SUPPLY
If the original power supply of this computer fails you open it (3 screws flat screwdriver) and check the fuse (cylindrical glass cruet with 2 metal "caps" on the 2 ends):
if it is burnt (broken internal wire and / or opaque glass and / or no continuity with the tester):
replace it with a similar one (specifications written on the original fuse: T1 / 250V).
C16 RED IGNITION LED WORKING BUT… BLACK SCREEN!
In these cases we have 3 main suspects in this order:
- CHIP TED (MOS) [integrated U1]
- CPU 8501 (or 7501) [integrated U2]
- PLA [integrated U16]
that you find in these positions on the board:
Fortunately they are mounted on a factory socket and therefore are easily replaceable but… they cost several tens of euros and can be replaced with other working ones. Obviously, being no longer marketed, these chips even if working will not last forever even if you put heat sinks on them (the problem that causes them to break is not in fact the heat but is due to the voltage peaks that occur during the on / off, words of those who developed them!).
