Super MVS convertor II
Uses a PAL18CV8 and two LS245 transceivers for the 68k data bus on the prog board. Two corresponding footprints for SIL pull-up resistors on the MVS side are left unpopulated.
The chip is actually a custom marked Altera MAX EPM240 CPLD. Boundary scan device ID replies BB085040 (EPM240 signature reversed) and the header on the back is for JTAG: