The Pro-325/350 were introduced in 1982 and the Pro-380 in 1985 by Digital Equipment Corporation (DEC) as high-end competitors to the IBM PC.

Like the cosmetically similar Rainbow 100 and DECmate II (also introduced at that time),[1] the PRO series uses the LK201 keyboard and 400KB single-sided quad-density floppy disk drives (known as RX50[2]), and offers a choice of color or monochrome monitors.

BYTE in 1984 reported that Venix on the PC outperformed the same operating system on the DEC Professional and PDP-11/23.

By comparison, many existing CP/M applications (see the Rainbow 100) were easily ported to the similar 8086/8088 chips and MS-DOS operating system.

Porting existing PDP-11 software to the PRO was complicated by design decisions that rendered it partially incompatible with its parent product line.

Industry critics observed that this incompatibility appeared at least in part deliberate, as DEC belatedly sought to "protect" its more-profitable mainstream PDP-11s from price competition with lower-priced PCs.

The failure of DEC to gain a significant foothold in the high-volume PC market would be the beginning of the end of the computer hardware industry in New England, as nearly all computer companies located there were focused on minicomputers for large organizations, from DEC to Data General, Wang, Prime, Computervision, Honeywell, and Symbolics Inc.[citation needed] The PRO-325 and -350 use the F-11 chipset (as used in LSI-11/23 systems) to create a single-board PDP-11 with up to six expansion slots[4] of a proprietary CTI (Computing Terminal Interconnect) bus using 90-pin ZIF connectors.

[citation needed] Other available operating systems include DEC RT-11, VenturCom Venix, and 2.9BSD Unix.

The RTI has two serial line units: one connects to the VAX environmental monitoring module (EMM) and the other is a spare that can be used for data transfer.