Famous Graphics Chips: TI TMS34010 and VRAM

Written by | Science

This is the latest installment of a series of short articles about graphics chips, controllers and processors, that changed the course of the computer graphics (CG) industry — The TI TMS34010 and VRAM introduced in 1986 by Texas Instruments. In 1984 Texas Instruments introduced TI’s VRAM, the TMS4161. The TMS34010 and VRAMs are related but not in the way one might think — Karl Guttag had started the definition of what became the TMS34010, having previously worked on the TMS9918 “Sprite Chip” and two 16-bit CPUs and the issue of memory bandwidth was a critical problem. The basic VRAM concept of putting a shift register on a DRAM was floating around TI, but the way it worked was impractical to use in a system. So Guttag’s team worked out a deal with TI’s MOS Memory group on how Guttag’s team would help define the architecture of the VRAM to work in a system if the memory division of TI would build it. In between the VRAM design, and the release of the 34010 Guttag’s team also developed the TMS34061, a simple VRAM controller, that they could get out much faster than the 34010.

In 1986 TI introduced the TMS34010, the first programmable graphics processor integrated circuit. It was a full 32-bit processor which included graphics-oriented instructions, so it could serve as a combined CPU and GPU. The design took place at Texas Instruments facilities in Bedford, UK and Houston, Texas. First silicon was working in Houston in December 1985, and first shipment (a development board) was sent to IBM’s workstation facility in Kingston, New York, in January 1986. Karl Guttag also personally showed a working 34010 to Steve Jobs at NeXT in January 1986. The Intel 82786 was announced shortly after the TI TMS34010 in May 1986, and became available in the fourth quarter. It was a graphics controller capable of using either DRAM or VRAM, but it wasn’t programmable like the 34010. Along with the chip, TI introduced their new software interface, the Texas Instruments Graphics Architecture (TIGA). TI claimed the 34010 was faster as a general processor than the popular Intel 80286 in typical graphics applications. The 34010, said Guttag, waits on the host 90% to 95% of the time with the way Microsoft Windows was structured by passing mostly very low-level commands.

TIGA was a graphics interface standard created by TI that defined the software interface to graphics processors, the API. Using this standard, any software written for TIGA should work correctly on a TIGA-compliant graphics interface card. The TIGA standard was independent of resolution and color depth which provided a certain degree of future proofing. This standard was designed for high-end graphics.

The chip had several dedicated graphics instructions. They were implemented in hardware and consisted of essential graphics functions, such as filling a pixel array, drawing a line, pixel block transfers, and comparing a point to a window. The chip supported Pixel Block Transfers, Pixel Transfers, Transparency, Plane Masking, Pixel Processing, Boolean Processing Examples, Multiple-Bit Pixel Operations, and Window Checking. There was also a graphics-oriented register indirect in x, y addressing mode. In this mode, a register held a pixel’s address in x, y form—the pixel’s Cartesian coordinates on the screen. The mode relieved the software of the time-consuming job of working out the mapping of each pixel’s memory address to its screen location.

Last modified: February 8, 2019