Autor ::Roman Bórik Poslaná :: 24.04.2015 11:50:53 Predmet ::Re: PMD-85A
On the following site you can find whole schematic of the PMD 85-2A (other models PMD 85 too). http://www.sapi.cz/pmd-85/pmd85-2a.php
You can try to replace old 1kB ROMs by new 4kB/8kB ROM.
ROM begins at 8000h and ends ar 8FFFh. Keep in mind that ROM is mirrored from 0A000h to 0AFFFh.