Hopefully we understand the behaviour of the current ASIC well enough for someone to create a replacement, or (as you're suggesting) and enhanced version that is backwards compatible. It's not a small task though!
I have a bunch of test programs that Dave and I wrote for SimCoupe, which tested tested various fringe cases and display quirks. It'd be cool for those to contribute back to real hardware :) Si On 8 Oct 2011, at 15:03, VELESOFT wrote: > > Hi. My project is SAM COUPE clone (but no ASIC replacement). First prototype > will based on big CPLD + fast Z80cpu + big sram + saa1099 sound chip. > > Here is components for first SAM clone: > http://velesoft.speccy.cz/other/ula-xc95288xl.jpg > > http://velesoft.speccy.cz/IMGP3176.JPG > > http://velesoft.speccy.cz/IMGP3178.JPG > > Priorities: > - compatibility with SAM COUPE > - more colours (minimal 256 colors palette) > - faster CPU > - possibility run at full speed 6MHz in all graphic modes (not contended > memory) > - better compatibility with ZX Spectrum (ZX mode can work as ZX128) > - big ram + big rom > - internal peripherals... > > Actuallly I must finish ZX projects: K-MOUSE 2011, complette RGB>VGA > convertor, ULA1 clone (zx clone based on old russian chil ULA1). After it I > can continue on SAM projects... > > VELESOFT