|#FB7F||%xxxxx0x1 0xxxxxx1||[[765 FDC]] (internal) Data Register||Read||Write
|-
|#FBDC||?%xxxxx0x1 xx0xxx00||[[Amstrad Serial Interface]] 8253 Timer counter 0||Read||Write
|-
|#FBDD||?%xxxxx0x1 xx0xxx01||[[Amstrad Serial Interface]] 8253 Timer counter 1||Read||Write
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|#FBDE||?%xxxxx0x1 xx0xxx10||[[Amstrad Serial Interface]] 8253 Timer counter 2||Read||Write
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|#FBDF||?%xxxxx0x1 xx0xxx11||[[Amstrad Serial Interface]] 8253 Timer Modus Select|| - ||Write
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|}