(HP-67/97) Othello for 67/97 40th anniversary

[Jean-Marc Verniajou]

This 199 steps program plays Othello*
The commented code and documentation is in the PDF attachments, English and French.
*LBL A
1
STO E
8
.
8
STO B
CLX
STO C
STO D
*LBL a
CLX
STO 9
STO A
RCL B
CF2
GSB 9
X=0?
F3?
GTO 0
*LBL b
2
.
2
STO A
*LBL c
SF0
*LBL d
RCL B
STO I
*LBL e
RCL A
1
.
1
-
X=0?
CF0
X=0?
SF2
RCL I
+
GSB 9
F3?
CLX
X=0?
GTO 0
X<0?
GTO 1
.
1
ST+ 9
GTO e
*LBL 1
F1?
X>0?
GTO 0
F0?
X>0?
GTO 0
CF0
GTO d
*LBL 0
RCL 9
FRC
ST- 9
1
0
x
x
ST- 9
RCL A
.
1
-
STO A
X<0?
GTO 2
FRC
.
2
X>Y?
GTO c
LSTX
INT
+
STO A
GTO c
*LBL 2
F1?
GTO 3
RCL B
+
STO B
RCL C
RCL 9
X≤Y?
GTO 2
STO C
LSTX
STO D
*LBL 2
RCL B
X>0?
GTO a
RCL D
X=0?
GTO 3
STO B
R/S
SF1
GTO b
*LBL 3
RCL E
0
X≤y?
R/S
*LBL B
CF1
X=0?
GTO A
STO B
SF1
SF0
1
CHS
STO E
GTO a
*LBL 9
STO I
SF3
INT
X=0?
RTN
9
X=Y?
RTN
LSTX
FRC
1
0
x
X≠0?
X=Y?
RTN
CF3
RCL (i)
X<>Y
4
X<>Y
Yx
STO 0
÷
FRC
4
ST÷ 0
x
INT
1
-
RCL E
STx 0
x
x<0?
RTN
F1?
F0?
RTN
F2?
GTO 9
X=0?
RTN
SF2
*LBL 9
RCL 0
ST- (i)
F2?
ST- (i)
RDN
RTN
*LBL E
8
STO I
2
1
8
4
5
*LBL 4
STO (i)
DSZ I
GTO 4
1
9
2
R/S
ST+ 4
ST- 5
CLX

*Othello® TM&©Othello,Co. and MegaHouse.

[Paul Dale]

A wild thought: changing the representation base to 10 would allow the board registered to be displayed (printed)...

My 97 is half a continent away or I'd give it a go.


Pauli

[Jean-Marc Verniajou]

(11-15-2019 05:30 AM)Paul Dale Wrote:  A wild thought: changing the representation base to 10 would allow the board registered to be displayed (printed)...
My 97 is half a continent away or I'd give it a go.

Hi Paul,
You're right. Thank you for your interest.
I first started to write this in 2006 as a challenge that no 70's Othello game programmer (I know some of them) bet a penny on, knowing the limited capabilities of the 67/97. At the time, I wrote it on a 41 with the precious help of continuous memory, and I had not enough time to shrink it below 229 67/97-steps. Using base 4 instead of base 10 helped me squeeze the code a few steps but was not enough to go below 229.
I found enough motivation (rage?) and a little time during 2016 and shrank the code to 199 steps. Staying below the 200 steps mark looked good to me, and I left things as is.
Best,
Jean-Marc