77.3.1. Data General Nova

77.3.1. Data General Nova
	77.3. Data General

Odkazy:

Data General Nova

Populární 16-ti bitový počítač.

Obrázek 77.1. Tvar istrukcí počítače Nova

NO ACCUMULATOR-EFFECTIVE ADDRESS
  0   1   2   3   4   5   6   7   8   9  10  11  12  13  14  15
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
| 0   0   0 |OP CODE| @ | INDEX |         DISPLACEMENT          |
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
                          0   0   (0;DISP)   ZERO PAGE
                          0   1   (PC+DISP)  PC RELATIVE
                          1   0   (AC2+DISP) INDEXED BY AC2
                          1   1   (AC3+DISP) INDEXED BY AC3


ONE ACCUMULATOR-EFFECTIVE ADDRESS
  0   1   2   3   4   5   6   7   8   9  10  11  12  13  14  15
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
| 0 |OP CODE|  AC   | @ | INDEX |         DISPLACEMENT          |
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+


TWO ACCUMULATOR-MULTIPLE OPERATION
  0   1   2   3   4   5   6   7   8   9  10  11  12  13  14  15
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
| 1 |  ACS  |  ACD  |  OP CODE  |  SH   |   C   | # |   SKIP    |
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+


INPUT/OUTPUT
  0   1   2   3   4   5   6   7   8   9  10  11  12  13  14  15
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
| 0   1   1 |  AC   |  OP CODE  |CONTROL|      DEVICE CODE      |
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+

Při nepřímém přístupu s pomocí adres 20_OCT-27_OCT je adresa v těchto slovech automaticky zvětšena o 1 (AutoIncrement). Při nepřímém přístupu pomocí adres 30_OCT-37_OCT je adresa v těchto slovech automaticky zmenšena o 1 (AutoDecrement).