What's New

16th Dec 1999 22:06 PST

Fixed some of the icons which were messed up and I updated the grossly out of date 'future projects' bit.

14th Mar 1999 23:59 PST

Finally finished the program updates, bug fixes and all the other bits and pieces that got in the way. Galaga'88 has been added into the JAS-SYSTEM1.
Click here for details and download ! JAS-SYS1 beta 1.2

26th Feb 1999 23:30 PST

Well ! It's been almost a year since any update to the JAS project and this one's good !  The system 1 emulation has gone so well here's the public Beta release of the first Namco system 1 emulator.

15th Apr 23:30 PST

JAS 1.1 - with PacLand support !! Took a while getting it ready.

Ok, performance is a big issue here. You'll need a Pentium 166MMX to get full frame rate, it'll also run on a Pentium 133 with the frame sync disabled, read the JAS.TXT file for details. 

New Features

- Screen shots can be made, in Windows .BMP format, by hitting F12 during gameplay
- Game names now also match the ROM directory name

8th Feb 22:30 PST

JAS-Multi Game in OUT !  Finally got the thing completed, all known bugs killed !  JAS ( Jrok's Arcade Emulator )  plays  Mappy, Gaplus, Dig Dug 2, Super PacMan, Galaga3 ( Midway version of Galplus ) and Sky Kid all  in one package.

New Features

- Full command line support, you can set every option from the command line
- All games have the quicksave game feature ( you just hit F1-F9 to save a game image).
- VESA  video mode for 400x300 & 320x240 pixels, this should fix any video problems !

If you want to run using the VESA mode's you'll a driver which can handle it, look at http://www.scitechsoft.com for a commercial VESA driver.

Development History

A quick history to the development of the Jrok's Arcade Simulator  ( JAS ).

After seeing the PATHETIC effort Namco made in emulating Mappy for the PC, running under winslows'95 it was terrible.  I decided it was about time someone wrote a decent Namco emulation ( for purely educational uses by owners of the original game boards ). Having already learned 6809 assembly programming, through another project, I figured that writing a simulator in x86 assembler wouldn't be a big deal, well the 6809's hardly got any registers and only a small number of instructions ( I think it's like 79 total).

So after a little coding, and a lot of debuggering, the 6809 simulator lived, a few days after that 'hey presto' the Mappy emulator was born! Unlike the official Namco release, which when run on a Pentium Pro @233MHz ( yes I overclock ) only manages 96% original game speed ( or only 31% if the screen is maximized ), mine achieves 100% speed of the original, even on an old Pentium 90 !!

The emulator was coded over a period of about 6 weeks, during the months of May to June. I was looking for something else to do rather than actually complete PC*Bert. The first release of the emulator was at the San Diego Classic Arcade party, have a look at some pictures from that event here http://www.spies.com/arcade/photos/index4.html

After getting the first version out, which were stand alone programs, I decided it'd be a good idea to merge them into one program. The core program can support multiple games, the specifics of each game are handled by a custom 'driver' to emulate the particular hardware. All emulated game share the 'core' routines which handle things like 6809 emulation, sound generation, sprite and text drawing.

The Emulator

The emulator core now supports 6 games completely, these are Dig Dug 2 , Gaplus, Galaga3, Mappy, PacLand, SkyKid and Super PacMan. Galaga 3 is the Bally Midway license of Gaplus, the hardware is identical.

I was going to to Pac'n'Pal but the game is just to horrible to do, besides it's emulated in Mame so it's not important. Same is true of The Tower of Druaga, which is basically a Dig Dug 2 boardset with additional colours. The game is TOO horrible though.

The emulator completely simulates the original game boards features the 6809E cpu's, all custom IC's and sound. It's totally encapsulated and contains no code of the original, all graphics, sound and program are read from the game ROMs and converted into more manageable internal formats for emulation 'on-the-fly'.

The 6809E emulation, screen, redraw and audio mixing is 100% assembler, everything else is in 'C'. Mappy & Super Pac should work on everything from a 486DX2-66 with PCI video upwards. Dig Dug 2 required a bit more CPU power so you'll need a p90 or better to run that game. Gaplus needs a lot of horsepower to simulate the three CPU's, it'll JUST run on a Penitum 133, providing you use Awe-32 or Gravis sound ( the soundblaster mixing slows it down too much ).  SkyKid and Pacland really eat up the CPU power, you'll need a Pentium 166MMX, with a good video card, to run these games at the full 60 frames/sec, they'll run well enough on a Pentium 133 providing you turn of frame sync, see the jas.txt file for details.

Video Modes, the emulator uses a custom video mode. Like the PacPc games the screen resolution is 224x228. THIS VIDEO MODE WILL NOT WORK ON SOME MONITORS. To fix this you need to get a VESA driver and use the 'V' mode on the command line.

Sound support for Soundblaster, Gravis Ultrasound/Interwave based card, AWE/SB32. So that should cover all the most popular sound cards. With the Gravis/Interwave and AWE/SB32 cards you do need RAM as I upload the waveform ROM to the card.

The emulator is also Windows'95 friendly. It won't trash windows, lock up, require you to download some obscure DPMI driver, add EMM386 to your config.sys or any crap like that. To enhance performance you might want to run the emulator in pure DOS only mode.

Screen Shots & Game Play

JAS in Action

Click image for screen shots of Gaplus, Mappy, Dig Dug2, Sky Kid & Super PacMan

walkpac2.gif (3448 bytes)Screen Shots from Paclandpac-run.gif (3848 bytes)

Dig Dug 2 - Click for game play details


Future Projects

Nothing much to report here, I should see about adding a few more games to JAS-SYS1 really.  But that's about it, other arcade related projects take my time so the arcade simulator doesn't get worked on... Oh well... it's not dead it's just 'resting'   (  and it's not nailed to its perch ).


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