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本文介绍用游戏卡作为PC机并行输入口的方法。该游戏卡插在PC机的8位扩展槽中,具有两个游戏端口。它由一个地址译码器(用于游戏端口地址201H译码的两只74LS138 和 74LS32)和四只NE558C定时器(它们将单只游戏
This article describes the game card as a PC parallel input method. The game card inserted in the PC’s 8-slot expansion slot, with two game ports. It consists of an address decoder (two 74LS138 and 74LS32 for game port address 201H decoding) and four NE558C timers (they will be a single game