Apple II port to BBC Master computer

[kieranhj]

There is a high pitched ding sound effect, similar to - I guess - gates fully opening or closing, or the spike sound, that plays occasionally. Seemingly out of nowhere, for no apparent reason. Even after playing all levels, it's still unclear to me what audio clue/indicator this is supposed to be. All I know is, from what I can tell, this is specific to your port. If you do not understand what I'm referring to, I could make a recording.

* The sound of a gate completely closing can be heard even if that gate is not visible.
Just like in the SNES version: viewtopic.php?f=122&t=4149

I also did some more digging to discover the origin of the mystery "ding" sounds that happen seemingly at random. It is actually the GateDown sound effect being played when a gate closes, regardless of where the player is in the level. To compound, if you have multiple gates closing then you will get all of the sound effects happening one after another even if you are many screens away. This is how the original Apple II code is written, and you can hear the effect on that version - it's just that the GateDown effect is just a small "tick" sound, not the more extravagent "ding!" that we have on BBC. Note that the code shares the same sound effect for GateDown and spikes appearing.

I decided to fix this by only playing the sound effect if the gate is present on the visible screen (or the gate is on the edge of the visible screen.)

[David]

I found a misspelling in the intro: https://github.com/kieranhj/pop-beeb/bl ... Prolog.png
It says "absense" instead of "absence".

[kieranhj]

I found a misspelling in the intro: https://github.com/kieranhj/pop-beeb/bl ... Prolog.png
It says "absense" instead of "absence".

Great spot, thank you! Have added to GitHub issues: https://github.com/kieranhj/pop-beeb/issues/153

[Norbert]

Is there any way you could cut down the 8 second loading time?
Maybe decrease the "BITSHIFTERS" promo?

[Edit: Video may be temporarily unavailable. If it is, please check back later.]

[Norbert]

Minor issue. Restarting insta-chomps the prince.
Only happens if death is by chomper (anywhere in the level), and the top row has that chomper.
Maybe the game doesn't reset the prince's horizontal position quickly enough - or something?

[Norbert]

How sure are you about the cheat codes for the 'released game', as mentioned by you in the README.md?
In particular the following:

KILL - Kill guard on screen
ZAP - Zap guard to 1 health

I'm asking because the cheats of the Apple II version include a ZAP that kills.
(I didn't look at the code of your port. Maybe you simply modified these.)

[kieranhj]

Hi everyone,

Just to let you know that I release v1.0 of the port last night. You can find more details and the download / online emulator here: https://bitshifters.github.io/posts/pro ... -beeb.html.

Big thanks again to Norbert and David for all their help playtesting, giving feedback on the port and explaining some of the finer details of the game that I wasn't aware of. Both have been incredibly generous with their time and immensely helpful for me to get to this point.

There are already a few compatibility issues and requests coming back, so there will no doubt be a v1.1 release soon, but for now I need to take a little rest!

Let me know what you think.

[Norbert]

Let me know what you think.

Congratulations on the release!
Solid port.

If you have time, can you look into this.
[Edit: Never mind. I looked into it myself.]

Also, currently, for me, make.bat results in:

version.txt:1: error: Bad hex.

EQUB $, $0/, $3/, $9:, $2 , "no"
^
Assemble failed!

[Edit: Probably simply doesn't work with Wine.]

Finally, can you tell me if there are any cheat codes currently unmentioned in the "Cheat Codes (Released game!)" section of README.md (e.g. easy guards)?

Too bad the GitHub code currently doesn't fully reflect the released version, even though you didn't make code changes after the release datetime.

[David]

version.txt:1: error: Bad hex.

EQUB $, $0/, $3/, $9:, $2 , "no"
^
Assemble failed!

[Edit: Probably simply doesn't work with Wine.]

version.txt is generated by this line in make.bat:

Code: Select all

echo EQUB $%DATE:~8,2%, $%DATE:~3,2%, $%DATE:~0,2%, $%HH%, $%TIME:~3,2%, "%USERNAME:~0,2%" > version.txt

This would extract parts of the current date with substring operations, assuming a certain date format (DD-MM-YYYY), and it creates garbage if the date format is different from that.
It doesn't work for me either because my system uses YYYY.MM.DD.

You could change the character positions or just enter fixed values.

[Norbert]

You could change the character positions or just enter fixed values.

Yeah, I already figured that out. Thanks anyway.
But then I noticed the GitHub code doesn't actually reflect the released port, so I decided to just ignore all the code and not build anything myself.

[David]

But then I noticed the GitHub code doesn't actually reflect the released port, so I decided to just ignore all the code and not build anything myself.

Take a look at the release-candidate branch.
If I compile the source on that branch, then the resulting disk image will match the released version from here, except for the few bytes that are the version number.

[David]

PoP crashed on level 12:

Here is the savestate:

crash_level_12.zip

(142.21 KiB) Downloaded 98 times

Unfortunately I did not save the game *before* the crash, so I can't easily test whether the game always crashes at that point.

[Norbert]

Take a look at the release-candidate branch.

Ah.

[kieranhj]

Hi Nobert & David,

Sorry for the slow reply - it's been a crazy few days. I see you have figured out the versioning system and located the build number within the disc image.

If you hadn't found them yet, the level files start at offset 0x24200 and are spaced 0xA00 bytes apart (not 0x900.)

I did change the cheat codes because 'Z' is a movement key (left) in the standard keyboard configuration, so settled on 'ZAP' and 'KILL'. I also added 'EASY' which just divides the guard strike and restrike probabilities by 2 to make the game a little bit easier for those of us who don't have the same reflexes as we did when the game was released!

Thank you for the bug report and save state file - I will take a look into this when I get chance. I'm taking a week's holiday so likely won't be for a while. I did complete the game myself before release and have had others report successful completion as well but there are still clearly some issues remaining so will do a V1.1 when I am happy with any fixes & changes.

For this build, to start the game directly (skipping the attract sequence) change the byte at offset 0x428 from 0x8A to 0xD5. (Changes the JMP AttractMode to JMP DOSTARTGAME.)

To alter the start level change the byte at offset 0x12F9 from 0x01 to the level number. (Changes the Accumulator register before JMP start in master.asm.)

I hope this helps! Thanks again for your help.

[Norbert]

For this build, to start the game directly (skipping the attract sequence) change the byte at offset 0x428 from 0x8A to 0xD5. (Changes the JMP AttractMode to JMP DOSTARTGAME.)

To alter the start level change the byte at offset 0x12F9 from 0x01 to the level number. (Changes the Accumulator register before JMP start in master.asm.)

Thanks.