On 1/19/15 11:45 AM, Seth Morabito wrote: What about the two documents I just uploaded? http://bitsavers.trailing-edge.com/pdf/att/3b2_hardware/

On 1/19/15 11:45 AM, Seth Morabito wrote: What about the two documents I just uploaded? http://bitsavers.trailing-edge.com/pdf/att/3b2_hardware/ [1]

Hi everyone, I've made tremendous progress on my 3B2 emulator. It's being implemented under the SIMH simulator platform, which has been a huge help. My WE32100 core is getting closer to being complete. I'd consider it alpha quality right now, but it has enough instruction coverage to pass the 3B2's power-on self tests and to (barely) run some of the 3B2 firmware mode tools. Implementing the WE32100 core has been thanks to the processor manual and assembly language manuals that are available on BitSavers, but outside of the CPU, virtually all of my understanding of the 3B2's architecture has come from studying the ROMs and the SYSVR3 source code. I've also been helped by having remote access to a running 3B2 so I can assemble and disassemble code using the real AT&T tools. Beyond that, I have found precious little documentation. I'm at the point now where I'm pretty well stuck until I can find more information. I understand large chunks of the memory map now and should be able to do things like simulate the floppy and hard disk controller, but there are large gaps in my understanding. There are many undocumented registers that are used by the firmware, but don't appear in the SYSV source code anywhere. What they mean and what they're for is anybody's guess. I've just stubbed them out for now. If anybody has access to schematics, architecture docs, or other memory map information, I'd be eternally grateful if you could share it! -Seth

* On Tue, Aug 11, 2015 at 09:36:36AM -0500, Jerry Kemp <other at oryx.us> wrote: Hi Jerry, Sadly, it's been stalled for quite some time now. Current status is pretty much the same as it was in January. The simulator can boot the 3B2/400 firmware, pass diagnostics, and read directories from virtual floppy disks. Unfortunately, it can't get much beyond that -- trying to boot the UNIX kernel still fails miserably. I'd hoped to have much better progress to share, but Real Life intervened by throwing me several major curve-balls in the first half of this year, and it's only now that things are really starting to settle down. Even so, two things are still really holding me up: 1. Lack of good documentation for the system design of the 3B2 2. Lack of access to a physical 3B2 I hope to get #2 sorted out soon(-ish), so I can run a 3B2 with a logic analyzer attached. There's still some mystery surrounding some system timers and interrupts that I need to figure out before I can really make progress. I'd still love to get #1 sorted out, too. There are some 3B2 internals docs on their way to Al Kossow that I hope will get scanned in the next few months, I think that would help greatly. Best Wishes, -Seth

Hello Seth, We were having a 3B2 discussion on the Sun Rescue list, and that got me to thinking about your emulator project. Can you share a status update? Is there anything us non-developers can do to assist? Thank you, Jerry On 01/19/15 01:45 PM, Seth Morabito wrote: > Hi everyone, > > I've made tremendous progress on my 3B2 emulator. It's being > implemented under the SIMH simulator platform, which has been a huge > help. >