Changes
/* PC Series (gray) */
** more RAM (8Kbyte; instead of 2Kbyte)
** more EPROM (8K+16K, or optionally 32K; instead of 16Kbyte)
** additional IBM character set (instead plain 7bit Epson/ASCII charset)
** AutoLF signal supported (enabled via J4 jumper; instead of GNDing the AutoLF input)
** and, maybe... additional italics support (DMP2000 doesn't explicitly mention italics support; though probably both DMP2000+3000 do support them)?