New port of Missile Command to the BBC Micro

[tricky]

I'm still feeling less than 100%, but COVID is passing.
I started playing with Atari's Missile Command a few weeks ago after first looking at it a few years ago!
I'm still not sure that it will be easy as the software pixel plotting routines are about 15X slower than the HW versions in the arcade game!
I've probably finished for the day, but here is a sneak peek with all buttons pressed on free play, hence the continuous two player game!

URL:https://youtu.be/EaHIyEWFTd0 View at 720p+ for 50hz, not that it matter much with this game!

[TobyLobster]

Looking very good - the BBC could do with a better Missile Command. What would the controls be? You choose which base to fire from don't you?

[tricky]

I was thinking:
single for button fires from the third of the screen that the cross hair is in.
Keyboard has three fire buttons.
PS/2 Mouse/trackball has three buttons.
You can use keyboard and mouse/joystick at the same time, like my other games.
I generally like all controls to enable as they are detected, but I'm not sure about analogue Vs digital joystick.

[TobyLobster]

Sounds good. Maybe if the chosen base to fire from is empty, then fire from the nearest one that isn't?
Re: digital vs analogue: I guess you could start by assuming a digital joystick. If you detect a joystick position that isn't close to the middle or extreme edge then you've found an analogue joystick.

[tricky]

I was thinking along those lines.
In most of my games I have no bytes to do any fancy checking, but space is looking plentiful, at least until I have to start adding code and sprites to speed up drawing.

[tricky]

I'm trying to map the mostly 4 colour (8 at the bottom) missile command to the beeb at the arcade resolution.
The actual colours change every couple of rounds, so this is just an example of how the palette could be used.
Currently the games usually runs at 50 fps, although 60 could be a simple change but can slow down a little with many explosions on screen.
The most noticeable difference is the holes left in the ground. These could match the arcade, but would slow the rendering down.

URL:https://youtu.be/106x0SGp9-g View at 720p+ for 50hz, not that it matter much with this game!

[TobyLobster]

Looking good, the colours work well and it looks smooth. The rapidly flashing colours might need an epilepsy warning though!

[tricky]

... The rapidly flashing colours might need an epilepsy warning though!

Try it on an original 24" (I think) arcade CRT!
Actually, it would be an easy change to not have the colour cycling.

[tricky]

I felt like a bit of beeb programming this morning so added keyboard support and now it seems playable.
There is no sound, no Joystick support, no trackball support and the keyboard movement speed is fixed.
Keys are 1 and 2 to start a 1 player or 2 player game.
Shift, Space and Return to fire from the three bases left to right.
Z X / * to move the target for your ICBMs.
Escape to quit the game cleanly (well, as clean as it can!).
Nothing about the port is final, but it should all be the same as the arcade game apart from where there aren't enough colour bits on the beeb!

Please feel free to make suggestions, no promises though

[lovebug]

Pure excellence as always

Well done tricky

[TobyLobster]

Very good - this plays very well already.

[tricky]

Added first pass at converting POKEY sound to the beeb - needs work!

[lovebug]

oh tricky you had covid sorry dude

get well soon

[tricky]

That was a few weeks ago now, the antivirals saw it off.
More sound tweaks!

[tricky]

Today, I added the code to support my PS/2 Mouse/trackball adapter to my version of beebem to try to debug why my new code firstly didn't detect the trackball and if I forced it, why it crashed the beeb!
It turned out that I had played a little fast and lose with the spec and on my emulated mouse, it was failing with a timing error.
I fixed the over optimised line of code and it worked in emulation and on real hardware, but I still have what looks like the same crash!
At least I can debug it in beebem and not with the scope by toggling fire button 2 to see where I have got to! :O
I'll use it for a while before publishing the beebem changes, but when I do, they will be based on the version of beebem I posted a couple of years ago with speech support and all my extra debugging bits

[tricky]

Here is the port so far:

TrickyArcadeMissileCmd.ssd

(15.5 KiB) Downloaded 34 times

Controls are:
1, 2 to start a one or two player game.
Z, X, *, / to move the target.
SHIFT, SPACE, RETURN or G, H, J to fire from the left, centre or right.

You can mix and match keyboard and other controls.

Digital joystick is the default, just press fire on the instructions screen.
Analogue trackball, joystick or in beebem analogue mouse stick is selected by pressing T on the instructions screen.
The first fire button will fire from the left if the target is on the left, right if on the right and centre when the others are empty.
The second fire button will always fire from the centre.

P will try to initialise a PS/2 device on the user port, wired as per my adapter post and uses the most basic commands (RESET and Read Data).
If using a PS/2 mouse/trackball, the left, middle and right buttons wil fire from the left, centre and right silos.

If you have one of my four fire button GESA pad adapters, you can press any fire button to auto select it.
If you have a SEGA pad and adapter, the buttons will fire (A) left, (B) center and (C) right.

I'm planning on adding the AMX mouse next, but as I don't have one, it will be based on the docs and the beebem implementation!

Any other requests, please add them to this thread.

I know someone mentioned something that I have, but can't remember what it was and can't find my stash as I haven't finished unpacking from September!

[RobC]

I'm planning on adding the AMX mouse next, but as I don't have one, it will be based on the docs and the beebem implementation!

PM me if you want to borrow one as I have more than I use.

[Pernod]

I'm planning on adding the AMX mouse next, but as I don't have one, it will be based on the docs and the beebem implementation!

I wouldn't trust the BeebEm emulation, it's implemented to satisfy the AMX software, and may have unexpected behaviour with anything else. I think this is a case where MAME would be a better test platform.

[tricky]

Thanks both of you, I'm implementing the code from the specs and will test in beebem.
If it works, I'll post the image here and if not, try name and try making my beebem match the spec.
RobC, posting an SSD is probably safer than posting rare hardware

[tricky]

I think that it was the Marconi trackball that someone asked about. This looks similar to the AMX Mouse wiring wise, the the code should be very similar.
I hope it wasn't anly supplied with Doomsday systems!

[tricky]

Here is an update with first pass at AM Mouse support.
It seems fine in beebem, but what I can't tell and havent found is what DPI it is and so if it needs scaling.
The PS/2 default seems fine for my trackball and the only PS/2 mouse I could find.
It would be good if anyone with an AMX mouse could try it and firstly check if the movement is in the correct directs and if all three fire buttons work as expected - Left should fire left and act as a 1P start, middle should fire middle and right fire right.
It would also beed good to know if the movement required on the mouse is reasonable, that is does the mouse move too fast or too slow - I know this is subjective, especially if you are used to PC mice with accelorations and adjustable settings.

TrickyArcadeMissileCmd.ssd

File updated 12:30

(15.75 KiB) Downloaded 37 times

PS File updated 12:30, same controls, just tweaked the sound a bit and made sure that the user via was set to defaults.

[Ukwebb]

Here is an update with first pass at AM Mouse support.

TrickyArcadeMissileCmd.ssd

the download isnt working Tricky

[Pernod]

Plays well in MAME, gets quite frantic a few levels in

[tricky]

Thanks both of you.

The download downloads OK for me and when transfered to SD card, work with SmartSPI on a Model B.
I know, I should do more testing, but only have Bs set up

Here is an update with first pass at AM Mouse support.

TrickyArcadeMissileCmd.ssd

the download isnt working Tricky

Do you mean that you can't download it or that the .ssD doesn't work for you?
If the .ssd, what are you trying it on?

Plays well in MAME, gets quite frantic a few levels in

Is that the game that works, or the game and AMX Mouse?

[RobC]

I think that it was the Marconi trackball that someone asked about. This looks similar to the AMX Mouse wiring wise, the the code should be very similar.
I hope it wasn't anly supplied with Doomsday systems!

Definitely available separately - I think it came with some sort of painting software. I have a few of these too if you need someone to test the code.

[tricky]

Thanks Rob, I'll add the code, but the only docs I have is a pin-out, hopefully that will be enough

[Ukwebb]

Thanks both of you.

The download downloads OK for me and when transfered to SD card, work with SmartSPI on a Model B.
I know, I should do more testing, but only have Bs set up

Here is an update with first pass at AM Mouse support.

TrickyArcadeMissileCmd.ssd

the download isnt working Tricky

Do you mean that you can't download it or that the .ssD doesn't work for you?

it was the actual download - just said "the file is no longer available", but it does work now - i have an amx mouse so fully intend trying this out later - got to go out just now tho

[Pernod]

Is that the game that works, or the game and AMX Mouse?

Both!

Thanks Rob, I'll add the code, but the only docs I have is a pin-out, hopefully that will be enough

Also supported in MAME so can be used for testing.

[tricky]

MAME is great, but I'm more used to working in beebem when debugging as it has many custom features
I just mention this in case people think that I'm not a fan of MAME.
I often use the debugger in MAME when porting ROMs to the beeb.

I guess a quick look at the two drivers in MAME should tell me how similar the two quadrature mice are, maybe they are even the same code with just the wires connected differently to the user port.

[tricky]

Just got a few minutes, so added the Marconi mouse but haven't tested it!
I have to go out and don't remember how to launch MAME with compact, DFS and .ssd with Marconi mouse in user port! - maybe later.
RobC, if it isn't too much trouble, maybe you could give it a go on HW?

TrickyArcadeMissileCmd.ssd

(15.75 KiB) Downloaded 39 times

This may be the final version, so any testing and bug reports are welcombe.