Parabellum's Projects Tracker - ISSUES

0000033: Incorrect sound emulation for VectorPilot

The sound emulation does not work correctly for the game VectorPilot (by Kristof Tuts). This is especially obvious for the player's shoot, that sounds quite different on the emulator and on a real vectrex.

Unlike most of the vectrex games, VectorPilot does not update the PSG register only once per frame (about every 20ms). Instead, it does modify the sound registers about every 5ms (roughly 4 times per frame) to output a high-quality sound.

By design, ParaJVE is only updating the sound wave at the end of every frame ; thus the "intermediate" writes to the PSG registers done by VectorPilot are ignored, plain and simple. To achieve a perfect rendering, the sound emulation sub-system must be refactored to update the waveform data whenever a PSG register is accessed (filling a temporary buffer, that will be consumed at the end of the frame, when the sound waveform is to be output).

0000006: Slight glitches in the DAC output sound (Spike)

When the CPU is writing digitized data sound directly to the sound output line (like it does when Spike is speaking, for instance), we can hear some small glitches in the sound emitted by the emulator.

0000031: Emulate the "buzz" sound of the original Vectrex

The very specific background "buzz" noise of the vectrex needs to be emulated in the audio engine - preferably as an optional feature.

0000013: Graphics garbage when displaying text in Moon Lander

The Moon Lander game obviously uses some hand-crafted routines to display its text, and the result is completely unreadable in the emulator (see attached screenshots).

0000007: Vector text position not properly aligned

When the system function is used to display some text on the screen, the text rendered in the emulator is not displayed at the exact expected position. The vertical coodinate seems correct, but the horizontal coodinate seems to be slightly offset to the right.

This bug is likely to happen for every text instance, but it is particularly noticeable for centered text, or for text that gets cut off to the right border of the screen (because of the offset).

0000011: The keyboard-mapped joystick doesn't work on Mac OS X

On the Max OS-X platform, whenever the user clicks an entry in the ParaJVE window's menu, the emulator loose the focus (When the focus is lost, the emulator doesn't receive any keyboard event anymore, so the joystick emulation doesn't appear to work anymore).

Temporary workaround:
To give back the focus to the emulator window after having selecting a menu item, the user just has to click once, anywhere in the game window.

0000008: Add emulation for the 3D goggles

The emulator is yelling for the 3D imager peripheral to be implemented... ;)

0000032: Render intermediate dots (vectors junctions)

Depending on the way the programmer coded his display code, on the real vectrex, there are points that appear at the vectors joints in vectors lists.

The current version of ParaJVE currently has an special function to automatically hide such points ; but with the introduction of the glow shaders, it might be a good idea to add an option to render these points again (maybe with slightly different brightness settings, in order to differentiate them from "true" dots).

0000026: Most games are runnning too fast

Although there has been a fix regarding the emulation speed (cf. issue 0000025), most of the games are still running too fast on the emulator.

For instance, the first level of Scramble is scrolled in 25 seconds in the emulator, while the same area takes 40 seconds on the real Vectrex.

There are other games that are obviously still running too fast. Good examples are Web Wars, or Pole Position.

0000029: Add VecFlash-cartridge emulation

Now that dual-bank switching is fully implemented (see 0000014), the next step is to emulate multiple-banks switching.

The model of choice is Richard Hutchinson's VecFlash cartridge, that can hold as much as 31 binaries (ie. banks) at once.

The bank 0 contains the binary responsible for displaying the games menu, and selecting the associated bank. The VecFlash cartridge controller's selects banks by receiving pulses sent from the PIA16 line on the cartridge port.

0000030: Add global support for bank-switching

ParaJVE now supports bank-switching (issues 0000014 & 0000029), and it would be a very good thing to have ParaJVD support it as well.

But beware, this involves much more than just updating the cartridge ROM area when a bank switch occurs... It also means that the sources for the newly selected banks have to be reloaded/updated, the breakpoints have to be revalidated, etc...

Also, the project management module will need to be updated to support multiple cartridge roms/sources (one couple per bank).

0000014: Add bank-switching support

Several homebrew developers have requested for ParaJVE to support bank-switching (for 64Kb ROMs).

0000028: Reload cartridge does not reload listing

Hi,

reloading the ROM cartridge is a pretty nice feature, however this does not trigger a reload of the listing in the debugger. Would be nice to have. Or at least a "reload listing" menu item. As far as I see there is currently no means to reload the listing...

Take care,
Martin

0000009: Allow ParaJVE to change games without restarting

With the current version, when you want to run another game, you have to exit ParaJVE, then restart it in order to select the new game to be played.

It would be very convenient to let ParaJVE switch directly to another game (without having to pass through the exit/restart process.

0000027: Provide an editor to manage the games configuration

The users can already execute any arbitrary ROM (by using the "Pick Another ROM..." button of the game selector dialog), but there is currently no easy way to add an entry in the predefined games list.

At the moment, one has to manually edit the configuration.xml file in order to add new entries and/or assign overlays.

It would be much better if ParaJVE had a dialog allowing the user to add/delete/edit entries graphically, without having to mess with the inner workings of the XML configuration file.

0000012: Poor sound emulation on Linux

On some Linux platforms, the sound emulation is very bad and has to be turned off. The main problem seems to be that the sound output is shredded (as if there was some kind of buffer underrun issue).

0000025: Bedlam runs way too fast

ParaJVE has some speed timing issues, nonetheless, the games usually remain playable.
An exception is Bedlam, that runs much too fast to be played correctly.

0000015: Provide a native launcher for Windows

On Windows platforms, the emulator is currently started via a batch command file (ParaJVE.bat). It would be much more conveniant to have a native executable to launch the emulator.

0000010: Add Document section : how to tweak the frame rate

"How can I change/force/tweak the emulation frame rate" is a frequently asked question that needs to be addressed in the User Guide.

This question is even more important because there is a timing bug that makes the emulation go much too fast on some dual-core CPUs (when using low resolution timers).

0000021: Implement a Save / Load feature (emulator state persistence)

Having a way to save the current state of the emulator, then load it back later will greatly benefit to ParaJVE : The player would then be able to suspend and resume long gaming sessions, as well as submit specific testcases if appropriate.

0000024: Overlays are too dark

The non-opaque areas of the overlays are too dark (the colours are not visible enough).
Also, the vectors shown through these transparent areas do not get colored enough (as they are on the real vectrex).

0000022: Fullscreen mode not available on Linux Ubuntu

On Linux Ubuntu 8.10 using the java-6-sun JRE (update 7), the "FullScreen" checkbox of the game selector dialog is grayed out (ie. unavailable), because the JRE reports that the system doesn't support fullscreen mode.

Installing and selecting the java-6-openjdk runtime (rather than java-6-sun) fixes the problem : the fullscreen checkbox is available again with this JRE.

However, it would be a good idea to provide a kind of fallback implementation that emulates fullscreen, for all these platforms that don't support a native fullscreen mode.

0000023: Add a project management module

ParaJVD does not provide any 'external' way to specify the debugged sources/binaries yet. At the time being, these files paths are hard-coded in the loader classes and cannot be changed without recompiling ParaJVD sources.

The debugger cannot be released until there is some kind of mechanism to define/select a Project to be loaded.

The minimum pieces of information needed to define a Project are :

Project name
ROM binary file
ASM source file
ASM sources folder (for 'games' that are made of more than one ASM source)

Additional pieces of information that could be added later :

Required peripherals (lightpen, goggles) , if any
Special requirements (Bank switching info, Onboard RAM, ...)
Overlay image file + Overlay information (displacement/scaling)
Miscellaneous project comments (author, version, notes, ...)
Any suggestion welcome... :)

0000019: Split the configuration.xml file into 2 different files

The configuration file currently contains both dynamic and static data.
The static data (the games definitions, that never changes when the configuration file is saved by the emulator) should be taken off the configuration file, and saved in a (static) content.xml file.

0000018: Add a new view : Screen Buffer

This is a feature that would greatly help when debugging the graphics routines (both for ParaJVE debugging, and for homebrew developers).
Ideally, it would be an OpenGL panel (like the main ParaJVE panel) that displays the current content of the work buffer, and the current position of the beam (so that the user could see the vectors being drawn in real time as he's stepping through the code).