Published on Jun 6, 2012
Just a homebrew computer, I built in my spare time. Specs are:
- MC68008 CPU, clocked with 10MHz
- 4MB dram
- dual SID stereo audio
- V9990 Video Display Processor
- IDE/ATA interface
- Floppy Disk interface (WD1770, DD)
- Real Time Clock (RTC72421)
- 10base-T LAN interface (CS8900a)
- two ps/2 compatible keyboard and mouse ports
- two Atari style joystick ports
- RS232 and parallel port
Just a short demonstration. Working so far: ATA/IDE (FAT filesystem), interrupt subsystem, RTC, audio and video system.
Sorry for the bad picture quality. This monitor is crap and I had to use composite instead of RGB. Second the computer boots into NTSC while the cam is PAL only. Well, the starfield demo is written to use PAL mode at least. :-)
The system is an ported version of Enhanced Basic 68k. It has been modified to use the V9990 for output and is linked with the open source FAT library from ultra-embedded.com.
The starfield demo uses doubble buffering. Back- and frontbuffer are switched while vertical blanks (via interrupts). Music comes from an SID file ("Passport" from the HVSC) which has been dumped with 50Hz. The player routine is called within the interrupt service routine, which meets this frequency in PAL mode.
Project website: http://www.ist-schlau.de/