| Business | Phone |
| Banctec Systems Inc 2120 Industrial Pkwy, Silver Spring 20904 | (301) 622-3500 |
| Terabyte Systems Corp 110 Whitmoor Ter, Silver Spring 20901 | (301) 593-7179 |
| Computer Entry Systems Corp 2120 Industrial Pkwy, Silver Spring 20904 | (301) 622-6400 |
| Key Computer Systems 11720 Kemp Mill Rd, Silver Spring 20902 | (301) 649-3090 |