C64 Keyboard Connector to DB-25 Female Connector

Here, you can find the connection schema for C128D like keyboard. This keyboard is used in my tower-64 together with an AT-keyboard. So, you need this information if you want to have a seperate compatible C64 keyboard.

Separate C64 keyboard can be consist of three parts:
1. C64 to DB-25(female) cable
2. 25 pin male switch-box cable (found in market)
3. Keyboard to DB-25(female) cable

For the first part, you can use the keyboard's own cable with its connector, since it's hard to find those connectors. Simply desolder the wires from the keyboard and solder them to the DB-25 connector as described below.

For the third part, you need a 20 line strip cable (actually you only need 18 line but 20 is a standard, and since I'm not a native speaker of this language, I don't know the correct term for this cable, sorry). This cable must be soldered inbetween keyboard and the second DB-25 connector.

There are color codes in original C64 keyboard cables, this may help you for not being confused in wiring. If you follow the schema below, you can end up with a C128D compatible keyboard (without C128 specific keys of course).

Here is the wiring:

C64 MotherBoard                     Keyboard

keyboard pins     meaning   DB-25   Label      Cable Color
---------------   -------   -----   --------   -----------
1                  gnd        1        I       white
2              not connected  2

3                restore      3        8       black
4              not connected  4

5                  r3         5        7       grey
6                  r6         6        6       purple
7                  r5         7        5       blue
8                  r4         8        4       green
9                  r7         9        3       yellow
10                 r2         10       2       orange
11                 r1         11       1       red
12                 r0         12       0       brown
13                 c0         13       H       grey-white
14                 c6         14       G       purple-white
15                 c5         15       F       blue-white
16                 c4         16       E       green-white
17                 c3         17       D       yellow-white
18                 c2         18       C       orange-white
19                 c1         19       B       red-white
20                 c7         20       A       brown-white

As it's seen above, there is one-to-one connection from pins to DB-25 By the way, to make a keyboard, I cut the C64 case and mounted the connector to the one of the sides. Then I connected this keyboard to the C64-tower with a 3 meters data-switch-box cable. And it works fine.

Ilker Ficicilar
filker@newton.physics.metu.edu.tr
c068214@orca.cc.metu.edu.tr

[Back]