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Found ENDC in wrong location in dwread.asm and dwwrite.asm. Corrected. Moved the native 6309 code in dwread.asm and dwwrite.asm into the H6309 labeled area and changed IFEQ H6309 to IFNE H6309. Also moved the 57600bps 6809 code to the default location. This change had been done in the old dwread.asm and dwwrite.asm files to make it easier to follow. Though these two files were overwritten from the HDBDOS project dwread.asm and dwwrite.asm files. So this conversion needed to be done again so it made the source easier to follow.
author drencor-xeen
date Wed, 23 Jan 2013 12:36:55 -0600
parents 7d70b7e1cb21
children aaba193af04f
line wrap: on
line source

***********************************

* 16 x 8 Multiply (24 bit result)

* OTHER MODULES NEEDED: none

* ENTRY: A = multiplier
*        X = multiplicand

*  EXIT: A = product byte 1
*        X = product bytes 2 & 3

 nam 16x8 bit Multiply
 ttl Assembler Library Module


 psect MULT168,0,0,0,0,0
 
MULT168:
 PSHS A,X save numbers
 LEAS -3,S room for product
 LDB 5,S get lsb of multiplicand
 MUL
 STD 1,S save partial product
 LDD 3,S get mupltiplier & msb of multp.
 MUL
 ADDB 1,S add lsb to msb
 ADCA #0 add carry
 STD 0,S save sum of partial products
 LDX 1,S get 2 lsb's
 LEAS 6,S clean stack
 RTS

 endsect