3b2_rom/Rev2

AT&T 3B2 Revision 2 ROM images

Standard ROMs

These images are ROMs used on Revision 2 System Boards, including the 3B2/300, 3B2/310, and 3B2/400.

• AAYYC.bin
• AAYYD.bin
• AAYYE.bin
• AAYYF.bin

These are binary images of Intel D2764A EPROMs from an AT&T 3B2/400. The 3B2 reads full 32-bit words, interleaved from the 4 ROMs. The low byte comes from AAYYC, the next byte from AAYYD, the next byte from AAYYE, and the high byte from AAYYD.

• COMBINED.bin

The file COMBINED.bin contains the output of interleaving the D2764A images, and contains 8,192 32-bit words.

• COMBINED.hex

This is a canonical HEX+ASCII dump of the COMBINED.bin file.

• COMBINED.s

This file contains a disassembled and commented version of the Model 400 ROM. It is a work in progress, and has not been fully commented yet.

Debug Monitor (DEMON) ROMs

These images are Debug Monitor ROMs that were an option on Revision 2 System Boards.

• DEMON_0.bin
• DEMON_1.bin
• DEMON_2.bin
• DEMON_3.bin

These are binary images of 16KB Intel D27128A EPROMs containing the AT&T 3B2 Computer Debug Monitor.

• DEMON_COMBINED.bin

The file DEMON_COMBINED.bin contains the output of interlaving the D27128A EPROM images.

• DEMON.jpg

Photograph of DEMON EPROMs installed in a 3B2/400.