A brief WIP update, nothing too exciting this time.
The GT family graphics boards are now working better and faster, and the implementation is starting to look a bit tidier as more pieces of the puzzle fall into place. There are still a few problems with clipping and line drawing, and anti-aliased drawing modes aren't supported at all, but the basics for all three models (GT, GT+ and GTII) are in place now. The main difference between these boards are the addition of double-buffering for the GT+/GTII, and a "highlight" plane (2bpp) for the GTDB. I'm not 100% sure how the latter is connected to the RAMDAC, but I'm pretty confident it will use the overlay/underlay functionality of the Bt459 (not implemented yet). Turns out the GTDB boards for the 6xxx systems also have an SCC which supports the keyboard and optional digitizing tablet, and also an InterPro mouse port, making the 6xxx system configuration approach more consistent overall.
Learning that the EnvironV Screen Manager likes to configure single-screen systems with a virtual screen by using 4 bits/planes for each screen helped, and it also meant I can finally get some "full" colour applications displaying properly (in all 256-colour glory). The screenshot below is from an application called ModelView, an image processing tool. It includes ray-tracing and video creation among its capabilities, typically relying on 3D MicroStation CAD files as its input, and even has an option to divide processing jobs up and execute them on networked systems, via another piece of software called NetVideo.
There are three work-fronts open now:
- C400 MMU support
- EDGE graphics support
- Improve network transmit/receive timing
Of these, the first is probably the highest priority because it's the main remaining obstacle to getting all the supported systems to boot and run CLIX. Unfortunately, there's almost no documentation on the hardware for these devices, unlike for the reasonably well documented C100/C300 version. The last item is necessary to get networking working reliably (basically, to add realistic delays into the transmission and reception of network data), so it's a MAME-wide improvement, rather than an InterPro-system specific one.