Atari VCS 2600

In february 2002 i've started developing for the Atari VCS 2600.
To be able to play homebrewn programs on my VCS 2600 i tried to modify a 32in1 game card (CX26163P) to use EPROMs on it.

Here is an abstract schematic of this PCB:
32in1-card schematic
 

Take a look at this modification if you would like to play 16 games of 4KB each instead of 32 games of 2 KB with this PCB.

Here are some pictures of the PCB of the 32in1 card:

32in1 card inserted into the 2600
As you can see, when playing you are normally facing the soldering side of the PCB.

The top side of the PCB (Move mouse over the several parts to get infos about them):
top side of the cardResistors for datalines d0-d5The 64 KB PROM, holds 32 games of 2 KB each.4024 chip, an 7-bit counter (5-bits are used as addresses A11-A15)7414 chip, used for a) inverting the A12-signal of the card slot to use it as /CE for the PROM and b) clock signal for the 4024 chipThis capacitor provides power for some seconds to the 7414 and 4024 chips, so the 4024 keeps its current stateTop1: D3Top2: D4Top3: D5Top4: D6Top5: D7Top6: A12 (used as /CE when inverted)Top7: A10Top8: A11 (not used because games have only 2KB)Top9: A9Top10: A8Top11: Vcc (+5V)Top12: Shield ground

Without the PROM:
top side without PROM

Bottom (soldering ) side of the card (Move mouse over the several parts to get infos about them):
bottom side of the cardResistors for datalines d0-d5The 64 KB PROM, holds 32 games of 2 KB each.4024 chip, an 7-bit counter (5-bits are used as addresses A11-A15)7414 chip, used for a) inverting the A12-signal of the card slot to use it as /CE for the PROM and b) clock signal for the 4024 chipBottom1: GroundBottom2: D2Bottom3: D1Bottom4: D0Bottom5: A0Bottom6: A1Bottom7: A2Bottom8: A3Bottom9: A4Bottom10: A5Bottom11: A6Bottom12: A7


28pin-EPROM-FLASH-socket adaptor:

Because it is more convenient to use an E2PROM or a FLASH-ROM instead of EPROMs (which have to be erased using UV-light), but FLASH/E2PROMs use a slightly different pinout, i've built an adaptor:
 
Schematic for the FLASH-ROM adaptor Modification for the A14-addressline Modification for the /WE-signal

The connection drawn in green is the A14-addressline; on a Xicor X28C256P-20 E2PROM which i'm using, the pin 27 is used as the write-enable signal /WE, so we have to connect this pin to Vcc (+5V) (yellow connection).


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