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--- blog:commodore_c64_dtv_hacking [2023/01/31 10:17] – [Commodore C64 DTV Hacking] john
+++ blog:commodore_c64_dtv_hacking [2023/01/31 11:29] (current) – [Power Supply] john
@@ Line 1: / Line 1: @@
 ====== Commodore C64 DTV Hacking ======
-~~TOC_HERE 2-5~~
 From [[https://en.wikipedia.org/wiki/C64_Direct-to-TV|Wikipedia]]:
@@ Line 9: / Line 7: @@
 > had previously designed the C-One.
-These are my on hacking the C64 DTV into a capable, full-features 8bit computer system.
+These are my notes on converting the C64 DTV into a capable, full-featured 8bit computer system. I've written these notes down since a lot of the information on the C64 DTV has been lost over the years. This is a combination of the old web pages I've found, technical specs and my own findings/diagrams used to build my own C64 DTV Computer System.
 {{:blog:c64:commodore64_dtv_mugshot-x600.jpg?200|}}
@@ Line 20: / Line 18: @@
   * 2048 kbytes ROM
   * DMA memory transfer engine
+  * Example serial/date codes:
+    * 041107
+    * 041103
 == DTV (version 2) ==
@@ Line 30: / Line 32: @@
   * 8bit digital audio
   * Chroma/Luma bugged - //fixable//
+  * Example serial/date codes:
+     * 050728
+     * 050919
+     * 050921
+     * 050927
 == DTV (version 3) ==
@@ Line 40: / Line 47: @@
   * 8bit digital audio
   * Chroma/Luma output fixed
+  * Example serial/date codes:
+      * 050927
+      * 051005
+      * 051008
+      * 060118
 == Hummer Game ==
-The 'Hummer' offroad game model is mostly similar to the later DTV, but a number of useful signals are not present on the board (i.e. it doesn't have all the joystick lines available), so it presents more of a challenge.
+The 'Hummer' offroad game model is mostly similar to the later DTV (version 3), so has all of the bugged-features fixes, //but// a number of useful signals are not present on the board (i.e. it doesn't have all the joystick lines available), so it presents more of a challenge.
 ----
 Realistically, the //best// version is clearly the DTV (version 3) which has all of the bugs fixed. But the DTV (version 2) is definitely useable if you are prepared to fix the Chroma/Luma output (linked below). Non-working blitter transparency is a pain, but could be worked around. If you want to take advantage of the unique DTV features, then the DTV (version 1) is **not** what you want.
+You can see that there is a period in September 2005 when the production of the DTV (version 2) change to the (version 3). If you want a fixed model then you need to look for serial numbers around or above **0509xx**.
 ==== Power Supply ====
-The DTV normally gets ~6v from 4x AA batteries in the joystick. But also has a red LED connected which regulates down the supply to the 3.3v circuitry on the PCB, as used by a number of the chips. If the DTV is removed from the case and original power switch and LED, it is important that a LED is refitted to remain as a regulator.
+The DTV normally gets ~6v from 4x AA batteries in the joystick. But also has a red LED connected which is used as part of the regulator circuit to reduce the supply down to the 3.3v circuitry on the PCB, as used by a number of the chips. If the DTV is removed from the case and original power switch and LED, it is important that a LED is refitted to remain as a regulator.
 //Note: The LED should have a **forward voltage** rating of **1.8v**.//
+=== Power Switch Wiring - DTV 1 ===
+On a DTV 1, the power switch is wired as follows:
+{{:blog:c64:img20230128171536.jpg?500|}}
+Note that the (black) ground wire is soldered directly to the battery tab (the - terminal). The floating (red) positive wire is soldered to the battery tab (+ terminal).
+=== Power Switch Sub-Board ===
+A more detailed image of the power switch sub-board:
+{{:blog:c64:img20230131102833.jpg?400|}}
+From left to right, the connections above are:
+   * LED - (~+3.3v return to PCB)
+   * LED + (+5v from PCB)
+   * VDD + (+5v to PCB, connected by switch)
+   * VCC + (+5v from battery compartment, connected to switch)
+Seen from above, and with the plastic cover removed, the power supply sub-board also has markings to indicate the connections:
+{{:blog:c64:img20230131103754.jpg?400|}}
+In summary:
+{{:blog:c64:c64_dtv_v1_psu.png?500|}}
+=== Power Switch Wiring - DTV 2/3 ===
 ==== Joystick Port 1 ====