4K HP 67 Games rom attached for testing

[Dieter]

(11-03-2016 02:33 AM)Gene Wrote:  Hmm. I checked the errata / NOP listings for all the HP-67 games pac programs and there were no changes to the SpaceWar program.

I do see what you mean, but sadly my real HP 67 card reader is not reading cards tonight. :-(

Well, there is a way to get a printed listing into an HP67... ;-)
On the other hand... do you also have a 41 with card reader ?-)

But do we have to know how the original program behaves? If it really has a bug here it's not how the 41 version should behave. Looking at the listing I'd say that the routine at LBL 0 returns the number of Alglogs (that's what the comment says) by comparing the input with register A, B and C (Alglog positions), adding 10 for each match. If this is correct, the routine is buggy.

BTW, the program does not seem to use the secondary registers, so R20...25 can be replaced by R10...15. Maybe I'll post a reviewed version that you can test.

Regarding the random number generator: here is an overview that shows which programs use a RNG with or without a seed prompt:

Code:

Prog   RND?  SEED?
------------------
2636   R00    yes
ST     ---    ---
ART    R00    yes
ML     ---    ---
OB     R01    no
CH     ---    ---
BSP    R03    yes
JT     R02    no
SPW    R09    yes
GF     R00    yes

The ones that do not use R00 can be easily modified so that a common RNG routine for all programs is possible. However, I am not sure if this saves memory. How many bytes does a call like XEQ"R" require? The simple frac(x+pi)² generator is merely 6 bytes...

Finally, I just did another BSP version with a bit more friendly output ("you win / "you lose"), requiring 174 bytes (compared to 173 for the current version) including a "SEED?" prompt. There also is a (very) slightly different version with just 164 bytes.

Dieter