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208 Part 3 The instruction-set processor level: variations in the processor

Section 1 Processors with greater than 1 address per instruction

c If j = 0, do not change u and v.

If j = 1, add one to v after each execution.

If j = 2, add one to u after each execution.

If j = 3, add one to u and v after each execution.

The modification of the u address and v address is done in program control registers. The original form of the instruction in storage is unaltered.

d On completing n executions, take (F1), as the next instruction. F1 normally contains a manually selective jump whereby the computer is sent to w for the next instruction after the repeat.

e If the repeated instruction is a jump instruction, the occurrence of a jump terminates the repetition. If the instruction is a Threshold Jump or an Equality Jump, and the jump to address v occurs, (Q) is replaced by the quantity j, (n - r), where r is the number of executions that have taken place.

Floating point instructions

64 Add FAuv: Form in Q the normalized rounded packed floating point sum (u) + (v).

65 Subtract FSuv: Form in Q the normalized rounded packed floating point difference (u) - (v).

66 Multiply FMuv: Form in Q the normalized rounded packed floating point product (u) . (v).

67 Divide FDuv: Form in Q the normalized rounded packed floating point quotient (u) ¸ (v).

01 Polynomial Multiply FPuv: Floating add (v) to the floating product (Q)i . (u), leaving the packed normalized rounded result in Q.

02 Inner Product FIuv: Floating add to (Q)i the floating product (u) . (v) and store the rounded normalized packed result in Q. This instruction uses MC location F4 = 00003 for temporary storage, where (F4)f = (Q)i. The subscripts and f represent "initial" and "final."

03 Unpack UPuv: Unpack (u), replacing (u) with (u)M and replacing (v)c with (u)c or its complement if (u) is negative. The characteristic portion of (u)f contains sign bits. The sign portion and mantissa portion of (v)f are set to zero. Note. The subscripts M and C denote the mantissa and characteristic portions.

04 Normalize Pack NPuv: Replace (u) with the normalized rounded packed floating point number obtained from the possibly unnormalized mantissa in (u)i and the biased characteristic in (v)c. Note. It is assumed that (u)i has the binary point between u27 and u26 that is, that (u)i is scaled by 2-27.

05 Normalize Exit NEj-: If j = 1 normalize without rounding until a master clear or until the instruction is again executed with j = 0.

References

Univac Scientific Electronic Computing System Model 1103A, Form EL 338

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