Hi,
Apologies if this info is already widely known, I haven't seen it mentioned before. I was looking for datasheets and other info about NES-on-a-chip ICs, and found an interesting site. (If anyone knows of other NOAC manufacturers, please let me know!)
V. R. Technology http://www.vrt.com.tw/ make a range of chips. There are datasheets, development tools including a fully-featured emulator and examples on their web site. For convenience, I have uploaded an archive of all the datasheets and other files, which you can get from http://rapidshare.de/files/47324611/VRT_files.zip.html (the archive is about 70MB).
Development software includes a C compiler, assembler, picture conversion tool (shows what images would look like on NTSC or PAL TV, or LCD panel), emulator (EmuVT - this seems very comprehensive, so is probably modified from an existing open-source NES emulator), tools for creating your own multi-game cartridges (demo archive includes an 8Mbyte ROM image containing Sonic the Hedgehog and (ahem) lots of other titles...).
There are several interesting features from both a hardware and software perspective. Take for example the VT03 chip:
There is a cool-looking development board, which has a daughter-board containing 32Mbyte SRAM, and a flash chip can be programmed using it too. That connects to a PC USB port.
Edit: The VRT_files.zip archive which I uploaded to rapidshare is no longer there, so I have uploaded the file to Fileserve: File name: VRT_files.zip File size: 70.39 MB
Edit 2: I have re-uploaded the VRT_files.zip archive to http://www.multiupload.nl/09JVN5CC9Q
Edit 3: VRT_files.zip uploaded to 4shared and Mediafire.
Apologies if this info is already widely known, I haven't seen it mentioned before. I was looking for datasheets and other info about NES-on-a-chip ICs, and found an interesting site. (If anyone knows of other NOAC manufacturers, please let me know!)
V. R. Technology http://www.vrt.com.tw/ make a range of chips. There are datasheets, development tools including a fully-featured emulator and examples on their web site. For convenience, I have uploaded an archive of all the datasheets and other files, which you can get from http://rapidshare.de/files/47324611/VRT_files.zip.html (the archive is about 70MB).
Development software includes a C compiler, assembler, picture conversion tool (shows what images would look like on NTSC or PAL TV, or LCD panel), emulator (EmuVT - this seems very comprehensive, so is probably modified from an existing open-source NES emulator), tools for creating your own multi-game cartridges (demo archive includes an 8Mbyte ROM image containing Sonic the Hedgehog and (ahem) lots of other titles...).
There are several interesting features from both a hardware and software perspective. Take for example the VT03 chip:
- 50/60Hz, PAL or NTSC selectable
- Stereo sound! There are two APUs, the second is accessed in the region $4020-$4035
- Optional "one bus" operation, i.e. a single ROM chip contains both PRG and CHR data. (Cartridges for the OneStation console probably use that feature.)
- Timer interrupt facility, can count down PA12 or HSYNC (scanline) transitions
- High-colour palette mode; according to the datasheet, there are 121 possible colours. Colours specified in $3Fxx and $3Fxx + $80
- Built-in bank selection hardware, change H/V mirroring in software ($4106 bit 0)
- 16-colour sprites and large sprites (16 pixels wide)
There is a cool-looking development board, which has a daughter-board containing 32Mbyte SRAM, and a flash chip can be programmed using it too. That connects to a PC USB port.
Edit: The VRT_files.zip archive which I uploaded to rapidshare is no longer there, so I have uploaded the file to Fileserve: File name: VRT_files.zip File size: 70.39 MB
Edit 2: I have re-uploaded the VRT_files.zip archive to http://www.multiupload.nl/09JVN5CC9Q
Edit 3: VRT_files.zip uploaded to 4shared and Mediafire.