Computer system comprising a storage configuration with access prior to ultimate address calculation

Claim 1

A computer system, comprising: a storage configuration having at least a first store with an address space of 2l possible word locations, and at least a second store consisting of 2m- 1 modules, where m > OR = 1, said modules together providing a second address space, said storage configuration further containing an unused address space defined as ''''void'''', between addresses of the address space of the first store, and addresses of the address space of the second store, said ''''void'''' having a capacity of 2l p- 2l addresses, where p is at least 1, said unused address space being further determined by how many number of times larger a module of the second store is, compared to the address space 2l of said first store; a calculating unit connected to said storage configuration wherein possible word locations in said storage configuration may be calculated on the basis of at least two address components; switching means interdeposed between said calculating unit and said storage configuration; at least two address registers, each supplying one of said address components for calculation of the word location in said storage configuration; detection means interdeposed between said address registers and said switching means for determining, before an address calculation is made in said calculating unit, for which of the stores a request for access is required, said determination being based upon at least a portion of at least one of said address components, said detection means after having made its determination, then supplying a relevant request signal to said switching means; and a second detection means connected to said switching means for signalling that an ultimate result of said address calculating unit is an address of said unused address space.