Notes For V2.9-9

1. New Features

1.1 SCP

- Circular register arrays are supported (mostly for PC queues).
- The timer calibration package has been generalized to support
  up to 8 timers.
- The terminal multiplexor library has new routines to disconnect
  a line, and to print connection statistics.
- RESTORE no longer fails if it can't find a register.  Instead,
  it attempts to skip the saved register data.  This process is
  not 100% reliable.
- The ENABLE/DISABLE commands have been replaced by SET <device>
  ENABLED/DISABLED, where implemented.
- Because ENABLE is used for device configuration, the modifier
  for write enabling a device is WRITEENABLED.
- The LOG/NOLOG command have been replaced by SET LOG/NOLOG, and
  SHOW LOG has been added to show logging state.
- SET VT/NOVT and SHOW VT have been added as a prelude to VT
  terminal emulation for Windows.

1.3 PDP-11, PDP-10 simulator

- PC queue implemented.
- SHOW STAT, SET DISCONNECT added to DZ11.
- SET ADDRESS implemented to support variable device addresses.

1.4 18b PDP, Nova simulator

- PC queue implemented.
- SHOW STAT, SET DISCONNECT added to TTI1.

1.5 PDP-8 simulator

- PC queue implemented.
- TTIX rewritten as a single multiplexor; SHOW STAT, SET DISC added.

1.6 HP2100 Simulator

- Additional disks implemented: 12565A, 12606B, 12610B, 13210A
- Additional tapes implemented: 13181A
- 12920A terminal multiplexor implemented
- Floating point implemented - not yet debugged
- DMS (dynamic mapping system) implemented - not yet debugged

1.7 Other simulators

- PC queue implemented.

1.8 Altair Z80

- Revised from Charles (Dutch) Owen's original by Peter Schorn.
- MITS 8080 with full Z80 simulation.
- 4K and 8K BASIC packages, Prolog package.

1.9 IBM 1130

- Written by Brian Knittel

1.10 Interdata

The I4 simulator has been withdrawn for major rework.  Look for
a complete 16b/32b Interdata simulator sometime in 2002, with
reader/punch, multiple terminals, hard disk, floppy disk, magtape,
and line printer.

2. Release Notes

2.1 SCP

The replacement of OLDPC by PCQ in most simulators will cause
errors in restoring saved configurations.

2.2 PDP-11

RSX11M+ now works correctly on an RQDX3.  M+ is very sensitive to
RQDX3 timing parameters; do not change the defaults.  Autoconfigure
may or may not work if the system disk is DU; if sysgen'ing, a
full manual configuration is recommended.

M+ has been verified with V3.0, V4.2, and V4.5; with DU, DB, and DR
system disks; and in Q22 and URH11 modes. 

2.3 HP2100

The HP2100 CPU has been expanded to include floating point and
dynamic mapping support.  These have not been tested.

2.4 VAX

The VAX simulator boots the hobbyist CD through SYSBOOT, restores the
starter system, and then restores the rest of the installation kit.
It can install and run layered products.  Problems have been reported
with heavy loads on the terminal lines (e.g., Kermit).

2.5 GCC Optimization

At -O2 and above, GCC does not correctly compile the simulators which
use setjmp-longjmp (PDP-11, PDP-10, VAX).  A working hypothesis is
that optimized state maintained in registers is being used in the
setjmp processing routine.  On the PDP-11 and PDP-10, all of this
state has been either made global, or volatile, to encourage GCC to
keep the state up to date in memory.  The VAX is still vulnerable.
