A few weeks ago, I merged my work-in-progress AT&T 3B2/400 emulator into the main SIMH source tree, and I realized that I should mention it here, where there may be particular interest. The 3B2 and 3B5 were main porting platforms for AT&T System V Release 3, and when I realized how scarce the equipment has become to find, I set out to write an emulator for the 3B2. It was rough going at points due to lack of documentation, but I was able to reverse engineer quite a bit of the system through reading the SVR3 source code, and of course strapping my own 3B2/310 to a logic analyzer. The emulator is fairly complete. It certainly works well as a standalone, single-user UNIX system. Support for multiple terminals is coming very soon (as soon as I find the time, that is) so it will soon be possible to allow multiple users to telnet into virtual terminals, similar to how the SIMH PDP-11 and VAX emulators work.

On Dec 7, 2017, at 18:36, Jason Stevens <jsteve(a)superglobalmegacorp.com> wrote: Wow so glad you got it to boot! It’s great that this reference platform is now ‘alive’ through emulation. To say these machines are super hard to find these days is difficult is an understatement. Even in the mid ‘90s finding anything for these beasts was a monster chore. Outside of college and using them for style and diction, I’ve only seen one paired with an AT&T Definity phone switch, but everything was quickly moving to NCR/SUN. Great job!! Sent from Mail for Windows 10 From: Seth Morabito Sent: Thursday, 7 December 2017 3:10 AM To: tuhs(a)tuhs.org Subject: [TUHS] AT&T 3B2/400 Emulator Hello everyone, A few weeks ago, I merged my work-in-progress AT&T 3B2/400 emulator into the main SIMH source tree, and I realized that I should mention it here, where there may be particular interest. The 3B2 and 3B5 were main porting platforms for AT&T System V Release 3, and when I realized how scarce the equipment has become to find, I set out to write an emulator for the 3B2. It was rough going at points due to lack of documentation, but I was able to reverse engineer quite a bit of the system through reading the SVR3 source code, and of course strapping my own 3B2/310 to a logic analyzer. The emulator is fairly complete. It certainly works well as a standalone, single-user UNIX system. Support for multiple terminals is coming very soon (as soon as I find the time, that is) so it will soon be possible to allow multiple users to telnet into virtual terminals, similar to how the SIMH PDP-11 and VAX emulators work. For now, information about the emulator lives here: https://loomcom.com/3b2/emulator/ Best Wishes, -Seth -- Seth Morabito web(a)loomcom.com

Speaking of which, does anyone have any plans on writing an emulator for the 3B1 (aka PC7300)?