The CQFD Scientus is the French version of the VTech Precomputer Developer. At this time VTech France had launched a new branch CQFD (it is French for "QED")

CQFD was announced in 1998 and stopped in 2001 (sources: ​https://www.lsa-conso.fr/cqfd-une-deuxieme-marque-pour-vtech,27091 , ​https://www.lesechos.fr/2001/02/vtech-france-a-la-recherche-dun-nouveau-souffle-710803 )

This machine is likely based on the same z80 chipset as many other VTech laptops. Interestingly it has an AM27C040 UVPROM, meaning the machine was produced in relatively small quantities so a custom mask ROM was not appropriate.

It uses the same soundchip as the IQ unlimited laptop (​https://alexandre.botzung.fr/fr/vtech-i-q-laptop), VTECH part number 27-05992-0-0. It appears to be based on TI MSP50C3x microcontroller.

The display is a mixed text/graphics one. It is based on a 14 x 4 characters matrix, but some characters have a 1px border around them, and some don't. This allows to display graphics in the central area, and text on the sides.

It is laid out as follows:

• 3 continuous columns of 1 char width
• 1 area of 7x4 chars
• 1 continuous column of 1 char width
• 3x4 characters with borders on both the side and bottom

Besides the ROM, soudchip, and CPU glob, there is an audio amplifier and a 74HC175 on board.

The motherboard is behind the display, and connected with wires to the bottom part of the laptop with the keyboard, printer and mouse port, and audio output.

Cartridge port pinout is apparently standardized for all VTech Z80 machines:

• A15, A12, A7, A6, A5, A4, A3, A2, D7, D6, D5, D4, D3, GND, GND, VCC, ??1, N/C
• GND, A14, A13, A8, A9, A11, A16, A10, A1, A0, D0, D1, D2, ??2, A17, A18, ??3, N/C

TODO: confirm which pins are /RD, /WR, /CE (these are probably the 3 remaining pins).

??1 is connected directly to the CPU ??2 and ??3 are also connected to the 74HC175 but it is not clear how that is used.