As part of the documentation for Bulgarian 8 inch floppy disk drive model ISOT 5071E / ES 5074 we add C13.060.216 TO (Technical Description) and C13.060.216 TS (Table of Signals).
Recently we acquired a brochure of Institute for Microprocessor Instruments and Systems in russian and english language, printed in 1500 units by Bulgarreklama.