Refactor in preparation for the addition of a Rev 3 simulator for the
3B2/1000 system.
This change also includes a full cleanup of the rat's-nest of includes
and externs that plagued the 3B2 simulator and made it difficult to
understand and maintain. Headers are now required in the following
order:
compilation unit -> "3b2_defs.h" -> {... dependencies ...}
Finally, HELP has been added to the CPU device.
- The previous fix for STRCPY introduced a new bug. STRCPY must always
copy the final NULL terminator of the string, but must NOT increment
the source or destination pointers for the NULL terminator.
- The CTC simulation did not correctly support streaming mode, which
can in some cases request reads that are not on 512-byte block
boundaries.
- To begin to support System V Release 4 UNIX, the NI card (called EMD
under SVR4) needed to support several more CRC codes for pump code.
This change adds support for the WE32106 Math Acceleration Unit (MAU).
The WE32106 is an IEEE-754 1985 compatible floating point math
acceleration unit that was an optional component on the 3B2/310 and
3B2/400.
The MAU is implemented using software floating point routines. As
always, there may be bugs, but the MAU currently passes extensive
floating point tests with exactly the same results as a real 3B2/400
equipped with a physical MAU, so I hope these are few.
This change also addresses some unused function parameter warnings
issued by GNU Flycheck (not generally used by the build process, but
useful when editing files with Flycheck enabled)
This change cleans up warnings issued when compiled with
-Wall.
- Removed unused functions and variables.
- Moved static declarations out of headers and into source files
- Added braces around initialization where suggested.
Adds a skeleton framework for CIO ("Common I/O") feature cards. The
first feature card to be implemented will be the "PORTS" serial MUX.
Part of this support involved reworking IRQ handling in the CPU. It
now respects both IRQ Vector and IPL.
This change also removes all 'assert(0)' calls from the simulator and
replaces them with generic "Simulator Error" halts. These should only
happen if there's a genuine logic error lurking somewhere.
This change is a major refactor of how DMA and the DUART interact.
DMA implementation can now be overridden by individual devices that
require DMA. Disk and Floppy both continue to use a generic DMA
implementation, but the DUART code replaces the generic DMA with its
own implementation that correctly rate-limits TX. Among other things,
this allows the simulator to work correctly with real serial
terminals. This functionality has been tested on an AT&T 5620 "Blit"
terminal, which can run the 'layers' windowing software from the
simulator.
The 3B2 emulator did not have support for traps, rendering debugging
under the simulator fairly useless. This change adds support for
trap handling. The 'sdb' UNIX debugger under SVR3 should now work
correctly.
This commit improves the integrated disk (ID) controller's behavior,
enabling full support for up to two 72MB (emulated WREN II)
integrated winchester disks.
Clock reset was not being handled gracefully at all, leading some
diagnostic tests not to pass, or not to pass consistently.
This change will "kick" the system clock whenever the timer divider is
reset, so the new divider is picked up immediately.
