FreeBee - AT&T 3B1 emulator
FreeBee is an emulator for the AT&T 3B1. It's a work-in-progress, but currently works well enough to boot the operating system and to compile programs with the standard C compiler.
Phil Pemberton -- [email protected]
There have historically been a few instability issues on the Mac OS X platform, related to the SDL libraries. I've not heard much about them.
Unfortunately I don't have a recent Mac, so I won't be able to reproduce or test issues which affect OS X versions later than High Sierra. Bugs will likely be left open until someone with a more recent system is able to look into them (unless you open a pull request with a fix!)
If you have an issue on OSX and have a Windows or Linux system, please try to reproduce the issue on there as it will be easier for me to test. Please list all the platforms you've tested on (and the result) in the issue.
In summary: all support is on a best-effort basis, but I cannot guarantee that bugs reported solely on Mac OS X will be fixed as I don't have the equipment to test with.
There is a workaround in the memory mapping emulation, which allows supervisor-mode writes to low memory. If this is disabled, the kernel will fail to boot
with a PAGEIN
or PAGEOUT
panic.
If anyone can figure this out,
- Revision P5.1 motherboard with 68010 processor, WD2010 hard drive controller and P5.1 upgrade.
- 720x348 pixel monochrome bitmapped graphics.
- 4MB RAM (2MB on the motherboard, 2MB on expansion cards).
- This is the maximum allowed by the memory mapper.
- Keyboard and mouse.
- WD2010 MFM Winchester hard disk controller.
- Two separate drives.
- Maximum 1400 cylinders (limited by the UNIX OS, see the UNIX PC FAQ, section 5.6).
- Heads fixed at 8.
- Sectors per track fixed at 17.
- Fixed 512 bytes per sector.
- Those numbers are the default configuration; see below for more information.
- WD2797 floppy disk controller.
- Double-sided, 512 bytes per sector, 10 sectors per track, any number of tracks.
- Realtime clock.
- Reading the RTC reads the date and time from the host.
- Year is fixed at 1987 due to Y2K issues in the UNIX PC Kernel.
- Serial port.
- Linux only: file 'serial-pty' is symlinked to PTY that can be used to access tty000
- Usage instructions: README.serial.md
- Printer port
- Modem
- You will get errors that '/dev/ph0 cannot be opened' and that there was a problem with the modem. Ignore these.
- Install the
libsdl2-dev
package - Clone a copy of Freebee (remember to check out the submodules too)
git clone --recurse-submodules https://github.com/philpem/freebee
- Build Freebee (run 'make')
- Download the 3B1 ROMs from Bitsavers: link
- Unzip the ROMs ZIP file and put the ROMs in a directory called
roms
:- Rename
14C 72-00616.bin
to14c.bin
- Rename
15C 72-00617.bin
to15c.bin
- Rename
- Arnold Robbins created a drive image installed with all sorts of tools: here
- David Gesswein created a drive image for the VCF Museum: here
- Uncompress either of these images in the Freebee directory and rename the image to
hd.img
, or create a.freebee.toml
file pointing to the image. (See the CONFIGURATION section of the man page.)
- Download the 3B1 Foundation disk set from Bitsavers: here
- The disk images on unixpc.org don't work: the boot track is missing.
- Use the replacement version of the
08_Foundation_Set_Ver_3.51.IMD
image which is available here.
- Create a hard drive image file:
- Use the
makehdimg
program supplied in thetools
directory to create an initialhd.img
file with the number of cylinders, heads and sectors per track that you want. Limits: 1400 cylinders, 16 heads, 17 sectors per track. - When using the diagnostics disk to initialize the hard disk, select "Other" and supply the correct values that correspond to the numbers used with
makehdimg
. - Alternatively, you can use
dd if=/dev/zero of=hd.img bs=512 count=$(expr 17 \* 8 \* 1024)
to create a disk matching the compiled-in defaults. Initialize the disk using the "Miniscribe 64MB" (CHS 1024:8:17, 512 bytes per sector) choice. - The second hard drive file is optional. If present, it should be called
hd2.img
. You can copy an existinghd.img
tohd2.img
as a quick way to get a disk with a filesystem already on it. When Unix is up and running, usemount /dev/fp012 /mnt
to mount the second drive. You may want to runfsck
on it first, just to be safe.
- Use the
- You can also use the ICUS Enhanced Diagnostics disk. A bootable copy is available here. Uncompress it before using.
- Install the operating system:
- Follow the instructions in the 3B1 Software Installation Guide to install UNIX.
- Copy
01_Diagnostic_Disk_Ver_3.51.IMD
tofloppy.img
in the Freebee directory. - If you wish to increase the swap space size, do so with the diagnostics disk before installing the OS. See these instructions.
- To change disks:
- Press F11 to release the disk image.
- Copy the next disk image to
floppy.img
in the Freebee directory. - Press F11 to load the disk image.
- Instead of
08_Foundation_Set_Ver_3.51.IMD
use08_Foundation_Set_Ver_3.51_no_phinit.IMD
from here. This will allow the emulated Unix PC to come all the way up to a login prompt after the installation.
- Files can be imported using the 3b1
msdos
command which allows reading a 360k MS-DOS floppy image.- Use dosbox to copy files to a DOS disk image named
floppy.img
. This image must be in the same directory as the Freebee executable (or path specified in the .freebee.toml config file). - If the floppy.img file wasn't present on boot or was updated, hit F11 to load/unload the floppy image.
- Run
msdos
from the 3b1 command prompt, grab the mouse cursor with F10 if you haven't already, then COPY files to the hard drive.
- Use dosbox to copy files to a DOS disk image named
- Another option is to use the s4tools here which allow you to export the file system image out of the disk image and import the fs image back. In particular, there is an updated
sysv
Linux kernel module which allows mounting the fs image as a usable filesystem under Linux.
You can scale the display by setting scale factors in the .freebee.toml
file.
Scale values must be greater than zero and less than or equal to 45. This
facility is useful on large displays.
- F10 -- Grab/Release mouse cursor
- F11 -- Load/Unload floppy disk image (
floppy.img
) - Alt-F12 -- Exit
- F1-F8 -- "soft keys" at bottom of screen
- F9 -- SUSPD key (brings up list of windows)
- Alt-Esc -- EXIT key
- Alt-Backspace -- CANCL key
- Page Up -- HELP key
- Page Down -- PAGE key
- Insert -- CMD key
- Enter -- RETURN key
- Alt-Enter -- ENTER key
- Pause Break -- RESET BREAK key
- AT&T 3B1 Information -- the "Taronga archive".
- Includes the STORE, comp.sources.3b1, XINU and a very easy to read HTML version of the 3B1 FAQ.
- Also includes (under "Kernel Related") tools to build an Enhanced Diagnostics disk which provides more options formatting hard drives.
- unixpc.org
- Bitsavers: documentation and firmware (ROMs), software
-
To make an MS-DOS disk under Linux (9 tracks per sector):
dd if=/dev/zero of=dos.img bs=1k count=360
/sbin/mkfs.fat dos.img
sudo mount -o loop -t msdos dos.img /mnt
... copy files to /mnt ...
sudo umount /mnt -
To make a 10 track per sector disk image, just use
count=400
in thedd
command and then format the disk under Unix withiv
andmkfs
. -
See this part of the FAQ on setting up multiple login windows.