731d99cf65
The WE32100 supports expanded datatypes for its opcodes, allowing an
opcode to override the default size (byte/halfword/word) expected by the
instruction. For example:
CMPH &0x10000,{uword}-8(%fp)
Without the {uword} marker, this instruction would only compare the
lower 2 bytes of -8(%fp) against the lower two bytes of the constant
value 0x10000, since the CMPH instruction compares halfwords. However,
with the {uword} marker, the CMPH instruction promotes the opcode from a
halfword to an unsigned word, sign extending if appropriate.
The CMP{W|H|B} instruction implementation in the 3B2 simulator was
ignoring any expanded type markers on its opcodes when checking whether
to set the "N" (negative) bit in the PSW, leading to a failure in
compiling GCC. This fix causes the instruction to honor the expanded
datatype in this case.
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|---|---|---|
| .. | ||
| 3b2_cpu.c | ||
| 3b2_cpu.h | ||
| 3b2_ctc.c | ||
| 3b2_ctc.h | ||
| 3b2_defs.h | ||
| 3b2_dmac.c | ||
| 3b2_dmac.h | ||
| 3b2_id.c | ||
| 3b2_id.h | ||
| 3b2_if.c | ||
| 3b2_if.h | ||
| 3b2_io.c | ||
| 3b2_io.h | ||
| 3b2_iu.c | ||
| 3b2_iu.h | ||
| 3b2_mau.c | ||
| 3b2_mau.h | ||
| 3b2_mmu.c | ||
| 3b2_mmu.h | ||
| 3b2_ni.c | ||
| 3b2_ni.h | ||
| 3b2_ports.c | ||
| 3b2_ports.h | ||
| 3b2_sys.c | ||
| 3b2_sys.h | ||
| 3b2_sysdev.c | ||
| 3b2_sysdev.h | ||
| README.md | ||
| rom_400.bin | ||
| rom_400_bin.h | ||
AT&T 3B2 Simulator
This module contains a simulator for the AT&T 3B2 Model 400 microcomputer.
Full documentation for the 3B2 simulator is available here:
Devices
The following devices are simulated. The SIMH names for the simulated devices are given in parentheses:
- 3B2 Model 400 System Board with 1MB, 2MB, or 4MB RAM (CSR, NVRAM)
- WE32100 CPU (CPU)
- WE32101 MMU (MMU)
- PD8253 Interval Timer (TIMER)
- AM9517 DMA controller (DMAC)
- SCN2681A Integrated DUART (IU)
- TMS2793 Integrated Floppy Controller (IFLOPPY)
- uPD7261A Integrated MFM Fixed Disk Controller (IDISK)
- Non-Volatile Memory (NVRAM)
- MM58174A Time Of Day Clock (TOD)
- CM195B 4-port Serial MUX (PORTS)
- CM195H Cartridge Tape Controller (CTC)
Usage
To boot the 3B2 simulator into firmware mode, simply type:
sim> BOOT
You will be greeted with the message:
FW ERROR 1-01: NVRAM SANITY FAILURE
DEFAULT VALUES ASSUMED
IF REPEATED, CHECK THE BATTERY
FW ERROR 1-02: DISK SANITY FAILURE
EXECUTION HALTED
SYSTEM FAILURE: CONSULT YOUR SYSTEM ADMINISTRATION UTILITIES GUIDE
NVRAM and Time of Day can be saved between boots by attaching both devices to files.
sim> ATTACH NVRAM <nvram-file>
sim> ATTACH TOD <tod-file>
If you have no operating system installed on the hard drive, on subsequent boots you will instead see the message
SELF-CHECK
FW ERROR 1-02: DISK SANITY FAILURE
EXECUTION HALTED
SYSTEM FAILURE: CONSULT YOUR SYSTEM ADMINISTRATION UTILITIES GUIDE
Once you see the SYSTEM FAILURE message, this is actually an
invisible prompt. To access firmware mode, type the default 3B2
firmware password mcp, then press Enter or carriage return.
You should then be prompted with:
Enter name of program to execute [ ]:
Here, you may type a question mark (?) and press Enter to see a list of available firmware programs.
Booting UNIX SVR3
UNIX SVR3 is the only operating system available for the 3B2. To boot UNIX, attach the first disk image from the 3B2 "Essential Utilities" distribution.
sim> ATTACH IFLOPPY <floppy-image>
sim> BOOT
Once you reach the SYSTEM FAILURE message, type mcp to enter
firmware mode. When prompted for the name of a program to boot, enter
unix, and confirm the boot device is FD5 by pressing Enter or
carriage return.
Enter name of program to execute [ ]: unix
Possible load devices are:
Option Number Slot Name
---------------------------------------
0 0 FD5
Enter Load Device Option Number [0 (FD5)]:
Installing SVR3
To install SVR3 to the first hard disk, first, attach a new image to the IDISK0 device:
sim> ATTACH IDISK0 <hd-image>
Then, boot the file idtools from the "3B2 Maintenance Utilities -
Issue 4.0" floppy diskette.
From idtools, select the formhard option and low-level format
integrated disk 0. Parameters for the default 72MB hard disk are:
Drive Id: 5
Number cylinders: 925
Number tracks/cyl: 9
Number sectors/track: 18
Number bytes/sector: 512
After low-level formatting integrated disk 0, boot the file unix
from the first diskette of the 3B2 "Essential Utilities" distribution,
and follow the prompts.