Threaded Mode | Linear Mode

Sylvain Cote · (This post was last modified: 06-22-2023 07:43 PM by Sylvain Cote.)

From the Software Developer Handbook, assembly code for the FORTH word → TIME

Code:

       FORTH

*                                TIMEASM

*                        FORTH TIME: Primitive

SAVEFP EQU #E717A           FORTH entry points:  Save FORTH pointers

GETFP  EQU #E71A5                                Recover FORTH pointers

STKLFT EQU #E7320                                Lift floating-point stack

CMPT   EQU #125B2          System entry points:  Read time

IDIV   EQU #0EC7B                                Full word integer divide

HXDCW  EQU #0ECB4                                Hex to decimal

FLOAT  EQU #1B322                                Integer to floating point

CLRFRC EQU #0C6F4                                Clear fractional part

DV2-12 EQU #0C4A8                                12-digit divide

* TIME : Read system clock in seconds; return result to X

       WORD 'TIME'

       GOSBVL SAVEFP

       GOSBVL STKLFT

       P=     5              *** workaround for bug 1084

       GOSBVL CMPT           C(W) = Time in hex 512ths of a second

*

ACLC24 A=C W                 Unsupported entry point. 12B79

       C=0 W

       P= 4

       LCHEX 2A3             C = 2A30000

       D=C W                 D = 2A30000 ( 24 hours in 512th's of a second )

*

       GOSBVL IDIV

       GOSBVL HXDCW

       A=C W

       GOSBVL FLOAT

       C=0 W

       P= 12

       LCHEX 512             C = 5.12

       GOSBVL DV2-12         A,B = Time*100

       GOSBVL CLRFRC         A,B = IP(Time*100)

       GOSUB TRUNCC

       C=C-1 X

       C=C-1 X               C = TIME

       SETHEX

       D0=(5) #2FBD0         X-Register

       DAT0=C W              X = TIME

       GOSBVL GETFP

       RTNCC

TRUNCC P= 0                  unsupported system utility at 12B4A

       LCHEX 00499           rounds 15-digit A,B to 12-digit C

       ?A<=C A

       GOYES TRUN20

       C=-C A

       ?A>=C A

       GOYES TRUN20

       C=0 W

       A=A+A A

       GOC TRUN10

       LCHEX F00

       C=A S

TRUN10 RTNCC

TRUN20 C=A W

       C=B M

       RTNCC

       END

Usage: (in FORTH environment)

Code:

TIME  F.  [endline]

edit 1: add Jean-François correction
edit 2: add missing TRUN routines