Mera–Elzab Meritum – a family[1] of Polish personal computers based on TRS-80 Model I with BASIC Level II.

[2][7][8][9] In the late 1970s and early 1980s, there was no small microcomputer available for the general public in Poland.

It produced terminals, monitors, and computers, but did not manufacture products for the mass consumer market.

[10] ITM was a small foreign company operating in Poland selling measuring systems.

Mera–Elzab analyzed existing western small computer systems and the following aspects were taken into account for a new product:[3] Based on the above assumptions, TRS Model I with BASIC Level II was selected.

Peripheral chips produced in Poland by CEMI factory for the MCY7880 processor (Intel 8080 clone) could be used for both the Z80 and U880.

Small businesses were the primary target market, followed by research and education institutions.

[2] The fathers of the computer were Zygmunt Korga, later technical director of Mera–Elzab and Paweł Podsiadło, an employee of ITM company.

The computer was presented to the public for the first time at the Poznań International Fair in the autumn of 1983.

The press pointed out technical specification is not impressive, especially lack of graphic mode.

[10] The computer never became popular, mostly because of a low number of units produced,[11] the price and technical specification were not competitive to other products,[8] and lack of software and documentation.

[5] The computer was equipped with parallel and serial port not compatible with TRS-80 Expansion Interface.

Parallel port was based on MCY7855 universal I/O chip which was Polish clone of Intel 8255.

Thanks to this chip the computer could generate sound (1 channel), initially using built-in speaker later using an amplifier in a monitor.

[5] There were some changes in ROM adding support for disk drive, parallel printer and second timer chip as a sound generator (which was never installed in production units).

Placed in a large 360×192×315 mm housing with a weight of 12.5 kg (with power supply for both devices).

In 1985, Mera–Elzab submitted to the Ministry of Education a proposal to create a network version of a computer for Polish schools.

[11] The network project was developed by scientists from the Computing Center of the Silesian University of Technology.