AltairZ80 uses 0 for the VM-specific HLT instruction stop code.
SCP defines SCPE_OK as 0.
SCP uses 0 to mean all errors ("ON ERROR").
The command "ON 0" will generate "%SIM-ERROR: Invalid argument: 0".
This PR changes the HALT stop code from 0 to 5.
This avoids a potential invalid pointer dereference when formatting
the return value from sim_instr() if it is < SCPE_BASE but greater
than the previously defined static array size.sizeof
Update simh.doc to reflect this generic change.
This commit adds a "PMMI" device to the AltairZ80 VM that emulates
the PMMI Communications MM-103 MODEM & Communications Adapter.
This device was added at the request of a Facebook user that is
attempting to preserve and document various relevant communications
programs for CP/M and allow users to experience communicating and
sharing information with other remote computers of the same time
period, all on modern hardware.
This device attempts to emulate the MC6860L digital modem chip in
such a way that communications software written for the PMMI MM-103 can
communicate over a serial port or socket without a phone line or
the ability to MOdulate/DEModulate data over a phone line.
This commit adds two new devices, "M2SIO0" and "M2SIO1", to the AltairZ80
VM. These two independent devices emulate "raw" 88-2SIO ports that can
be used instead of the "SIO" device for attaching socket and serial
ports using TMXR.
These changes facilitate more robust parameter type checking and helps
to identify unexpected coding errors.
Most simulators can now also be compiled with a C++ compiler without
warnings.
Additionally, these changes have also been configured to facilitate easier
backporting of simulator and device simulation modules to run under the
simh v3.9+ SCP framework.
The first disk controller made by North Star was a single density
controller (MDSA). This was followed by the double density controller
(MDSAD) that is already supported in SIMH. This update adds support for
the single density controller as device MDSA. Since the controllers are
not software compatible, this update allows running of older software
designed for the MDSA controller.
