An apparatus for processing a sequence of instructions, which comprises a LCALL instruction, a FCALL instruction and a common re-jump instruction (return), comprises a means for reading-in an instruction, to perform the read-in instruction of a means for examining the instruction. In the case of the presence of LCALL or FCALL, a stack memory is filled, while the stack is emptied in the case of the presence of a re-jump instruction. At every re-jump, a predetermined amount of re-jump information is taken from stack and supplied to a means for decoding, which is formed to access the stack again in the case where the predetermined amount of re-jump information indicates a change of the physical memory window, to finally supply the correct address for the next instruction in the instruction sequence to the means for reading in. Thereby, the same re-jump instruction can be used for a call with FCALL (outside of a current physical memory window) and a call with LCALL (within the physical memory window), without a microprocessor change, by encoding the re-jump information on the stack and by decoding them by the means for decoding. Thereby, the re-jump instruction provided for the microprocessor can be used for both jump instructions.