Thomson EF9345

Lore & Background

The EF9345 was a single-chip microprocessor dedicated to video image control, housed in a 40-pin DIP package. It was primarily employed in the Matra Alice 32, Matra Alice 90, and Philips VG5000 microcomputers, and also in Minitel 1b terminals built by either Alcatel or Philips, with total production exceeding 2 million units. The chip could display 8 colors from an RGB palette, 128 alphanumeric characters, and 128 semigraphic characters.

It offered one semigraphic mode and two text modes: 40 characters × 25 rows (similar to teletext) with an 8×10 pixel font, and 80 characters × 25 rows with a 6×10 pixel font. The 40-column mode supported selectable background and foreground colors, and styles including double height, double width, blinking, reverse, underline, conceal, insert, and accentuation of lowercase characters. The 80-column mode supported blinking, underlining, reverse, and color styles.

The on-chip character generator provided several character sets, including alphanumeric and videotext-compatible semigraphics. The chip could output at 50 or 60 Hz, with interlaced or progressive scan, and addressed up to 16KB of dedicated video RAM.

Reader's Guide

The EF9345 is notable as a semigraphic video processor that powered several home computers and the widely deployed Minitel 1b terminals, with more than 2 million units produced. Its integration of a character generator, multiple text modes, and support for 8 colors made it suitable for both consumer computing and teletext-like applications. The chip's 40- and 80-column text modes, along with semigraphic capabilities, provided flexibility for alphanumeric and simple graphical displays. Its use in the Matra Alice 32, Alice 90, and Philips VG5000 microcomputers placed it in the European home computer market, while its role in Minitel terminals gave it a significant presence in early online services. The EF9345's design, with an on-chip character generator and dedicated video RAM addressing, reflects the transition from discrete video logic to integrated video controllers in the 1980s. Its successor, the Thomson EF9347, continued this lineage.

Did You Know?

• The EF9345 was used in more than 2 million Minitel 1b terminals built by Alcatel or Philips.
• It could display 8 colors from an RGB palette and 128 alphanumeric characters.
• The chip supported both 40-column and 80-column text modes, with different font sizes and style options.
• It was encapsulated in a 40-pin DIP package and could address up to 16KB of dedicated video RAM.