A friend is stymied in getting his emulator for the Panasonic JR-200 computer complete. The machine uses some parts that are long discontinued. I'm hoping someone here might have an old databook that contains more information that can currently be found on the web. The MN1800A was apparently equivalent to the 6802. He has that working and so no mystery there. I just bring it up since the other parts were perhaps related. MN1544 -- here is the most information I can find after an couple hours of googling: 4-Bit Microcontroller-Microcomputer On-Chip RAM (Bytes)=1k On-Chip ROM (bytes)=4k Number of Interrupt Lines=2 Number of Maskable Interrupts=2 No. of I/O Ports=6 Vsup Nom.(V) Supply Voltage=5.0 Package=DIP Pins=N/A Military=N Technology=NMOS MN1271 -- Likewise, MN1271 Peripheral Interface Adapter (PIA) - Universal Interface Adapter Word Size=16 Data Transfer Type (S/P)=Multimode Vsup Nom.(V) Supply Voltage=5.0 Package=DIP Pins=64 Military=N Technology=CMOS If anybody has any more information than this, my friend would appreciate it. BTW, his emulators, including the JR-200, are here: http://www.geocities.com/emucompboy/ Thanks