CBM Game Cartridge Configuration

Date: 2001-07-25 10:47:02

Hi All,

I have noticed something I cannot understand when I tried to reverse
engineer the schematic for a couple of CBM cartridges. The cartridges have
jumpers which are either soldered or not depending which memory config is

When configured for games running in Ultimax mode, the /IO2 line is often
found to be connected to the EXROM line. I can only decipher this to mean
that access to $DF00 will map in the ROM to $8000. But what holds it there??
Would it not disappear without a capacitor or something to hold the EXROM
line low?

- Nick


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