Each of the speeds greater than 9600bps deliver a character in less than
1ms. Computing inter-character delays in microseconds therefore can't
be precise enough to be well behaved. Measuring the inter-character
delays in instructions (scalled by the calibrated clock) gets us the needed
precision.
Data arriving on simulated serial ports can arrive faster than the OS running
on the simulated system can deliber it to user mode programs. This happens
when chunks of data are delivered to the mux from a network connection.
This can be due to a file transfer program (kermit) running on the other end
of a network connection and the packet size being delivered exceeds the
simulated OS's type ahead buffer size OR from users who paste arbitrary
blocks of data into a telnet or console session.
This is necessary to avoid kernel type ahead buffer overruns when a user
pastes a chunk of data into a console session as described in issue #246
Other console input speeds can be set with SET CONSOLE SPEED=nnn
A SET CONSOLE SPEED=nnn, where legal values for nnn are common serial
port rates. The speed value will attempt to limit the input data rates to a
simulator to approximately the specified bits per second.
The conversion of time to instructions can overflow an int32 when the
current instructions per second is high and the delay interval is high.
We limit the instruction delay to the maximum value available in an int32,
which for essentially all cases won't matter since the resulting delay is used
for a drop dead timeout and doesn't need to be precise or it will be
canceled before it ever fires anyway.
simh debug integration is only done during simh builds, the original QEMU debug functionality is preserved. The slirp debug flags can be set by the environment variable SLIRP_DEBUG. Mask values 1 - CALL, 2 - MISC, 3 - ERROR.
This should work on all byte addressable host systems using GCC/clang to build.
The QEMU slirp code has been pried out of QEMU and stubs have been created to solve where the current slirp is entangled with the QEMU code. Ths slirp/simh directory contains all the necessary include and glue files to make this useful. Everything in the slirp directory is unmodified QEMU code.
This version of slirp is a fork from QEMU Version 2.4.0.1 slirp implementation
Taken from commit id of 474590efc51f262fb5d81ca417d510cb7fb7a914
in the qemu repository git://repo.or.cz/qemu/ar7.git
Thanks to Fabrice Bellard.
Vector values contained in device information blocks are the true bus relative vector values. CPU specific biased vector values are produced by the respective vector fetching logic and vector values are limited to 9 bits with <1:0> = 0 as specified in both the Unibus and Qbus documents.
Prior logic attempted to load the desired file from the current default directory and if that failed wrote the in memory boot code image to the desired file and then retried the desired load..
A user can still explicitly load a ROM image with a "LOAD -R romfile.bin" command prior to a BOOT attempt if they want to test or otherwise run with a different ROM.
Update description of DEVICE, UNIT, and REG. Correct a number of
typos and formatting glitches. Add description of UNIT_IDLE,
REG_UNIT. Add some missing details in fprint_sym and
sim_vm_is_subroutine_call. Document command matching rule.
cygwin now includes development packages for the SDL2 and SDL video
libraries (libSDL2-devel and libSDL-devel). Adjust makefile to find the
libSDL2.dll.a or libSDL.dll.a library.
