Yes, pin 7 of the modem port is for +12V. The pinout of the DE-9P (except for some early boards with a female DE-9) is: 1 Gnd 2 TXD 3 (not used) 4 MSB (Modem Status Bit) 5 CTS 6 RXD 7 +12V 8 MCB (Modem Control Bit) 9 RI The Tech manual goes on to say all signals are TTL, and the interface is "extremely vulnerable to damage through misuse." Also, some modems with RS-232C connectors need an external adapter box so that the OI isn't damaged. modem port Bob -----Original Message----- From: Gary Hildebrand [mailto:ghldbrd@ccp.com] Sent: Monday, December 16, 2002 11:33 PM To: cctalk(a)classiccmp.org Subject: Re: Computers with ports coming out the front? Lawrence Walker wrote: Besides number of pins . . . . I think the 9 pin Modem port was for the accessory modem and has DC feeding the box that fits in the disk bay. The RS232 could be configured to drive a serial printer which was the common interface back then, especially on daisywheels. Gary Hildebrand St. Joseph, MO