mirror of
https://github.com/hsoft/collapseos.git
synced 2024-11-30 23:18:06 +11:00
17 lines
539 B
Plaintext
17 lines
539 B
Plaintext
|
Structured flow
|
||
|
|
|
||
|
|
z80a also has words that behave similarly to IF..THEN and
|
||
|
|
BEGIN..UNTIL.
|
||
|
|
|
||
|
|
On the IF side, we have IFZ, IFNZ, IFC, IFNC, and THEN,. When
|
||
|
|
the opposite condition is met, a relative jump is made to
|
||
|
|
THEN,'s PC. For example, if you have IFZ, a jump is made when
|
||
|
|
Z is unset.
|
||
|
|
|
||
|
|
On the BEGIN,..AGAIN, side, it's a bit different. You start
|
||
|
|
with your BEGIN, instruction, and then later you issue a
|
||
|
|
JRxx, instr followed by AGAIN,. Exactly like you would do
|
||
|
|
with a label.
|
||
|
|
|
||
|
|
(cont.)
|