Minor bug fixes and changes are not listed.
Users (+country) who suggested changes are shown in brackets.

R54 (20 February 2023)
Bug fixes, updated distance to ILS pt A (7500m)
Version 53 intermediate repair, not released.

R52 (20 November 2022)
Bug fixes and improvements.
Versions 50 and 51 intermediate test versions.

R49 (25 February 2020)
Better figures in guiding building models with reflection objects
English files language files are EN instead of UK

R48 (20 February 2020)
All F-keys changed to number keys due to common lap-top design.
Code verified and re-built during extensive tests.

R47 (20 July 2019)
Rebuilt for JAVA as A110J. Test version under development. Runs
100 times faster then DOS version. Uses the same user code as A110,
and can be run in te same directory as the A110 DOS version.

R46 (20 February 2018)
Updated with more efficient code and minor bug fixes.
Maximum number of reflectyion objects set to 11.

R45 (20 February 2017)
Updated with more efficient code and minor bug fixes.

R44 (20 July 2013)
Expanded frequency (40) will always be on (Wills-UK)
4 DOSBox instances can be run independently using “Alt-W”
Maximum number of scattering objects set to 14 (Wills-UK)
R43 (20 June 2012)
Scatter objects resolution improved to 0.1m (Wills-UK)

R42 (20 January 2010)
Updated with more efficient code to run with DosBOX

R41 (20 September 2006)
Scale on Approach can be toggled Threshold – Antenna

R40 (20 September 2005)
Orbit range can be selected NM or meters.
Ground curent mode removed to yield more memory space
Bug fix in Sensitive area in searching for further areas
Show recommended LF filter values on approach

R39 (20 August 2003)
More accurate (F9) listing from data file in SNS (Bakken-NO)
Lateral offset of approach track can be set (Hicham-CAN)
Scale on Approach now shows distance from Threshold (M.Wills-UK)

R38 (20 March 2002)
Sensitive area can be saved as ‘data.xl’ file (Bakken-NO)
Fixed Position, change of antenna also when using +/- keys in graph
Run mode settings stored with model files (Daemen-NL)

R37 (20 November 2001)
Bug fix: BBP not shown when ddm selected in Orbit Mode (Schulkes-NL)
Antenne spacing can be increased with an entered factor by Alt-P

R36 (20 February 2000)
Better control over the Front-Back ratio

R35 (20 April 1999)
More omnidirectional receiver antenna diagram (Engels-NL)
Corrected SBO/CSB phase reading for cursor (Hooijenga-NL)

R34 (03 December 1998)
Cursor stretched to mark the entire vertical scale (T.Brown-UK)
Approach cursor measure distance both from Antenna/THR (Spanner-UK)
(F9)key in Approach shows bend amplitudes in Zones 1-5 (Bender-D)

R33 (09 August 1998)
Theodolite can be located in FWD direction on Approach & Orbit

R32 (25 May 1998)
Toggle CLR ON/OFF by Alt-C will re-compute graphs directly
Rx filter (rad/s) can be adjusted in Approach mode

R31 (20 February 1998)
Adjustable Front/Back ratio of antenna elements (Wipf-CH)

R30 (20 October 1997)
Antenna designer faster to use in Chebychev mode (K›hler-DK)
Corrected offset of curves when using %DDM
New labelling of F-keys in all modes
Fixed position mode can invert sense and use cursor (Spitz-F)

R29 (20 March 1997)
More accurate definition of approach parameters
Approach mode with new option for amplitudes along run (Greving/D)

R28 (10 October 1996)
Reflection plane slopes only active when no scattering objects
Corrected sign errors in some curves
Antenna error settings independent of ADU feed readings (Aslaksen-N)

R27 (10 October 1995)
Multiple Orbit with sparate distance/level (m) setting
(1) adds -90deg and (9) adds +90deg in SBO from modulator
Internal changes

R26 (31 March 1995)
Run mode data (dist. start, stop etc) were corrupted with
old version of the AL.004 file. Version is now checked.
Antenna system file can now be changed in Network Mode
Corrected remaining DATA when loading library files (F7) (Spitz-F)
Save most run-mode settings & toggles in setup mode (F3)
Alt-F2 Will copy scatter objects in “F8-Scatter Editor”
Workfile & Saved Screens directories easier to administrate
Scatter object made of several sheets can be offset as one unit
Different receiver types may be simulated in Orbit Mode
Modulation Sum (SDM) displayed in Orbit mode by Alt-S

R25 (20 april 1994)
SCATT.GB file contains a number of models for scattering objects
Scatter phase computation modified for certain sheet orientations
Modified scatter computation for systems with separate clearance array

R24 (20 December 1993)
Corrections – save clearance array when CLR Tx off (Kristiansen-N)
CDI/DDM and Meters/Feet selections added to default setup.
Bug fix – could not change antenna system in setup mode (F3).
Adjustments in some antenna element radiation diagrams (Breien-N)
Bug fix – Overview (A-key) not responding to SBO phase (Nyback-N)
10 show directories under Mode 1 for storing/deleting screens
10 work directories under (F7-key) for storing models

R23 (20 September 93)
Internal changes in the software organisation.
Scatter objects picked by F2 and F3 keys instead of S and W

R22 (20 August 1993)
Overwrite protection if attempting to save an existing file name
Antenna designer (F4) compute SBO and CSB course array separately.
(F6)key enables Excel readable output file in Table output mode
Corrected erratic reading of saved files in release 21.

R21 (05 August 1993)
Modified file format – Scatter sheets are measured from bottom edge
Approach distance scale may be shown in meters, feet and NM.
Scatter objects may be loaded from a list in the SCATT.LST file
Most Character-key functions (L)oad (S)ave etc changed to F-keys
Multi language version. All texts are loaded from disk files.

R20 (20 June 1993)
Optional Bend Limits for Cat I, II or III on Approach graph
Wire sections can be simulated as scattering object (Bartlett-GB)
Alt-D toggles readings and curves between %DDM and æA (Wipf-CH)
Approach distance scale may be shown in Nautical Miles
Scatter location and orientation shown on Approach graph (Spitz-F)

R19 (20 April 1993) [NEW MAIN RELEASE]:
Alt-T Insert practical random tolerances in antenna feeds (Greving-D)
Alt-M Toggles measures between meters and feet
Some Hot-keys changed from one-key to Alt-keys.
Threshold distance adjustment in Control Panel corrected (Rchardt-D)
Bug Fix – Sensitive Area mode could lock computer (Hermens-NL)
Warning if Course Sector has been changed after a run (Breien-N)
Correction in BBP processing for Orbit mode (Haaland-N)
3D mode forced on when having reflection objects.
F9-key loads antenna system *.ASY files directly (Bastman-SF)
External DATA files enabled for Mode 3 and 5 (Wipf-CH)
Printout can be set for printers with Roman8 character set.
Set aircraft speed and receiver/plotter response (Rchardt-D)
Library files are selected with cursor keys (Rchardt-D)
Toggle panels in each Mode for faster selections (Bastman-SF)
Sensitive Area mapped for CAT I, II and III on given conditions.
New modular format on saved files for better grouping of DATA.
Antenna system *.DEF files converted to *.ASY files
Reflection sheet can be lifted from ground level and tilted.
New scatter integration algorithm for upto 16 simultaneous sheets
based on the Fresnel-Kirchhoff diffraction integral for
computation of reflection, diffraction and shadowing.

R18 (20 April 1992):
Beam Bend Potential referenced to SBO graph in Orbit Mode 3
Right-Left arrow keys also display BBP values in Orbit-graph
Modified systems can also be saved as new DEF files by F7 key
Common height can be set for Clearance-Only elements (Rchardt-D)

R17 (20 February 1992):
Ground current separately for SBO, CSB and CLR signals.
Replay speed can be adjusted by ñ keys (Ala-Mello-SF)
Full scale deflection range expanded to ñ6 – ñ800æA
0-key enables graphic cursor to measure relative dB values.
Move cursor between amplitude curves with up/down keys.
Move cursor along curves with left/right keys in Mode 3 and 5

R16 (20 January 1992):
More feed parameters information in graphic printout sheet.
Graphic Colours can be user edited in the AL.009 file
S key toggles ground slopes FSL & SSL between ø and % (Rchardt-D)
Files library directory may be selected by user (Rchardt-D)

R15 (20 October 1991):
Right-Left arrow keys display values in Orbit-graph (Erlandsen-N)
Direction may be reversed in Approach mode (Nilsson/Strandh-S)
New format on saved files gives better system handling.

R14 (20 April 1991):
B Key toggles between Black & White and Colours (Berglund-N)
Default settings in Runmodes initiated from AL.004 file.
Invert, save, load and replay graphic screens (Brown-GB)

R13 (20 March 1991):
Reflection factor may be added to objects at runtime (Rchardt-D)
adds Clearance to Course curves in Orbit w/Dual freq.
Clearance elements may use a separate element type (Rchardt-D)

R12 (20 March 1991):
Capture effect computed by multiple Fourier instead of Butterworth
Hot keys de-activated when not in Control Panel (Bastman-SF)
Orbits may use multiple runs on same diagram (Dullaart-NL)
Re-entry of Licence number required when updating to R12.
Bug fix – element azimuth diagrams in nearfield incorrect.
Improvement in scatter computations off specular angles.

R11 (22 September 1990):
Bug fix – Cursor jump in (F8-key) and color bleed (Bastman-SF)
VLOC graph Mode 5 selectable Deviation or Modulus (Breien-N)
A Hot-key list all feeds including DEV/DDM values (V„re-SF)
DD Hot-key toggles Control Panel readings %DDM and æA (V„re-SF)
Corrected failure to find best screen at first registration.
Type ‘EXIT’ prompt always on as a reminder while SHELL to DOS
Improved error handling (Krosby-N)
Clearance array may have separate antenna heights (Schwendener-CH)
(G)raphics or (S)cale direct at all Menu options (Antila-SF)

R10 (20 June 1990):
Bug fix – error when making VLOC radiation diagram files (Bakken-N)
Improved design of the Control Panel for setup simulations.
DB Hot-keys toggle amplitude readings dB/percent (Krosby-N)
C Hot-key toggles Clearance Signals ON/OFF (Krosby-N)
Re-entry of Licence number required when updating to R10.

R09 (08 June 1990):
ADU output DEV (æA) displayed separately for Clearance (Krosby-N)
Improved Sector computation in CrossOver Mode.
Amplitude graphs for SBO & CSB in Fixed Position Mode (Nyback-N)
DEF file format change – Antenna elements in each DEF file.
ADU SBO Attenuator enabled for antennas listed in DEF file (Garder-N)

R08 (08 May 1990):
ADU output DEV (æA) for each antenna is displayed.
FSL and SSL impact on signals enabled
Bug fix – refl. objects on FLY RIGHT side ‘invisible’.
F4-key enables simple design of new antenna systems.

R07 (27 April 1990):
Colours can only be set in F3 mode ,change setup (Schwendener-CH)
7 Hot-key for colour control for screen text.
Rejects old AXIS 100 files due to new definitions.
Improved bend synthesizing of airport buildings.

R06 (16 April 1990): [AXIS 110]
Fixed Position module added as item 6 in the menu
Ground Current module added as item 7 in the menu
Bend Analyzing module added as item 8 in the menu
Generates the SBO/CBS radiation diagram file for VLOC if
not present for the actual antenna system, or on users
request on simulating system errors.
VLOC Scatter routine can be run as a sub module
for either Cross Over or Approach modes.
Reflection objects defined as vertical reflecting walls
Upgraded to version 110 with additional features.

R05 (01 April 1990):
SBO attenuator adjustable in 1/100 dB steps (Garder-N)
Enabled Hardcopy printout of Tables (Krosby-N)

R04 (06 March 1990):
Course Sector Setting adjusts the SBO Attenuator (Garder-N)
Amplitude graphs in either dB’s or Percent (Bastman-SF)
3 Thomson CSF antenna systems added to the AD.DEF list (Dubois-F)

R03 (17 February 1990):
2 Plessey antenna systems added to the AD.DEF list (Strandh-S)
M Hot-Key toggles between fast 2D and true 3D models.
Approach mode activated for A) and T) runs.
New AL.DEF file format for longer System Label field.
3 Wilcox antenna systems added to the AD.DEF list (Strandh-S)

R02 (07 February 1990):
The AL.DEF file contains a list of upto 99 standard
antenna systems available from ‘NAMEx.DEF’ files.

R01 (06 February 1990):
All Normarc antenna systems (4 off) as built-in DEF files.
First version built up using many of the modules from
AXIS 310. Only the Orbit Cross Over Module is active.

1990 : Written for Training and antenna system evaluation
purposes on IBM compatible machines as AXIS 100
on request from Dag Strandh, CAA Sweden.

1983 : Ultra-compact P-N6/12 and C-N6/12 releases
2.0 – 2.4 written for Casio FX-702 and LLZ releases
7.0 – 7.9 for CASIO PB-700. Main usage is portable
field work and advanced training courses (Krosby & Holm).

1979 : Developed as an advanced versatile tool for
simulation of localiser behavior under erronous
operation and adverse environment.
Written in HP-BASIC on HP9845 Computer as LZ1 in
a number of versions up to 1983 (Bakken & Holm).

…. and before that – we used slide rules, which we
did not have any software for…