VCL-M/8 Rastergraf High Resolution Intelligent PMC Graphics Controller

The Rastergraf / Peritek VCL-M High Resolution Intelligent PMC Graphics Controller is a single board 34020-based graphics display controller for PMC equipped VMEbus, CompactPCI, and other PMC/PCI Bus computers. The VCL-M/8 includes an 8-bit overlay. The overlay screen can remain static while the primary scrolls (or vice versa).

The display memory which is used for the primary and overlay can be combined to support either primary-only double-buffered or high pixel count (e.g. 2048 x 1536) displays.

The 40 MHz TMS 34020 32-bit Graphics System Processor draws random points at a 10 Megapixel per second rate, and normal pixblt, pattern fills, and vector generation at up to 40 Mpix/sec rate. Hardware acceleration features include color and writemask registers, VFILL, and VBLT, and can give up to 160 Mpix/sec on a block write.

The 34020 can receive interrupts from the PMC Bus, serial I/O, and vertical sync. It controls the video timing, supporting almost any screen resolution from 256 pixels to 2048 pixels, at 30 to 80 Hz vertical and 15.7 to 100 KHz horizontal refresh rates. Standard display formats range from 640 x 480 to 1600 x 1280. Interlaced and non-interlaced formats are supported. A PLL clock generator allows the user to change the pixel clock.

The VCL-M supports binary vertical zoom (1,2,4,8,16), non-integer horizontal zoom (by virtue of the PLL pixel clock), horizontal pan and vertical smooth scroll. The display memory uses VRAMs, which gives about 95% availability to the 34020 and host processors. The display size ranges from 1 million up to 4 million addressable pixels.