Thanks to Kuniji Ikeda, we have been informed that the Japanese hardware developer called Illegal Function Call started to distribute its new slot expander MSX Simple 4Slot Expander. The main goal was to introduce a low-cost solution by omitting some technical specifications such as bus buffer, power supply, or audio mixing circuits. Anyway, those options were not completely removed from the design. An external power supply can be plugged into the board switching a jumper and sound outputs are available by soldering RCA connectors (plus other modifications) and then mixed externally.
Moreover, there is a board extension plus a flat cable available for those interested. This device has been tested on several MSX computers, however, some incompatibilities were found with few models. Please, refer to github developer's site for more information. The price is ￥14,190, approximately 90 €.
Relevant link: MSX Simple 4Slot Expander at BEEP shop
Relevant link: MSX Simple 4Slot Expander at Kaden no Kenchan
