Jane's Longbow 2/Anthology: Rocketing to success

A discussion on optimising the Jane's Longbow 2/Anthology setup to maximise rocket effectiveness.and suggestions for effective use in-game.

The issue

When engaging targets with the FFAR rockets, they will often seem to fall hundreds of metres short of the actual vehicle being engaged, despite there being a solid valid lock with the I-beam reticle on the HUD.

This has been an on-going issue which seems to have begun around the release of v2.09 patch and/or the use of cpu's exceeding the recommended specs of the game.

Subjective opinion seems to lean towards, higher spec cpu's, or the v2.09 patch or a combination of both creating the issue or increasing ithe impact to the point it affects gameplay.

The issue isn't due to emulation as the issue was present with higher spec legacy cpu's as indicated by Flyboy's FAQ (see: Why do the rockets fall short of the targets, even though I have a valid lock?).

Increasing effectiveness

These following suggestions cover changing the PCem virtual machine used to play Longbow 2, to try and reduce the impact of the issue.

AmnHLT driver

Use of the AmnHLT driver was discussed in the Longbow 2//Anthology setup guide, Jane's Longbow 2/Anthology: Rocketing into PCem, and is repeated below:

There is an additional virtual device driver that can be installed to increase the performance of the 86Box emulator. Quoting the VOGONS post by Jo22:

AmnHLT is a third-party VxD that issues a HLT (halt) instruction to the CPU whenever Windows 9x is idle. It's meant to avoid a 100% processor usage in VMs - and emulators. HLT is supported by late 486 processors and higher.

It can be obtained from the VOGONS post by SA1988. AmnHLT.7z is a 7zip archive. Only the amnrefr.vxd file is required from the archive.

The following installation instructions were provided in a VOGONS post by 0x6A7232:

• In Win98SE, open regedit.

• Go to HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\VxD.

• Create a key named AmnHLT.

• Create a binary value named Start with a value of 00 inside the AmnHLT key.

• Create a string value named StaticVxD with a string of AMNREFR.VXD inside the AmnHLT key.

• Shutdown the operating system and close the emulator.

• Copy amnrefr.vxd driver into the C:\Windows\System folder of the virtual hard disk.

• Start the Win98SE virtual machine.

Credit and thanks go to VOGONS members Jo22, SA1988 and 0x6A7232.

Limiting Voodoo Graphics frame rates

The Voodoo Graphics emulated in the PCem Win98SE virtual machine can be frame rate limited to 30fps. This seems to help as high frame rates may also contribute to the issue, as discussed in the SimHQ forums post, Rocket pod problems.

These steps should be carried out within the Win98SE virtual machine:

• Add the following to end of autoexec.bat in the PCem VM:

call c:\windows\glideenv.bat

• Create the file c:\windows\glideenv.bat.

• Add the following Voodoo environment variables to the file:

SET SST_SCREENREFRESH=30
SET FX_GLIDE_SWAPINTERVAL=0

Choosing a CPU

The virtual machine motherboard ([Super 7] FIC VA-503+) was chosen as it supports a wide range of cpu's and cpu speeds. Given that the issues also seems to be somewhat dependant on the host machine, this allows for testing multiple cpu speeds and selecting the 'subjectively' best one for your machine.

The CPU can be changed within the PCem virtual machine config, without having to make any other changes, making it convenient to change and test.

Recommendations are for an emulated cpu speed between 166-233MHz. In addition it may be worth testing alternatives to Intel CPU types, such as the IDT WinChip 200.

Game considerations

Targeting & engaging

When engaging a target the targeting mode should be set to TADS with the laser designating the target. In the casual flight mode the laser is used automatically but should be manually enabled for realistic flight mode.

There can be a huge 200m discrepancy between the range reported by the PCR mode and the TADS range. Rockets are more accurate using TADS targeting with the laser.

Speed & altitude

The following SimHQ thread, LB2 Rocket Issues discusses speed and altitude issues when employing rockets. From my own testing I've found rockets work best at:

• Very low speed, 15-20kts or less and it's usually better to hold position and hover.

• An altitude of 100ft+ works subjectively best although there are alternatives discussed in the SimHQ post including the position of the flight path marker in relation to the I-beam reticle.

Final word

Unfortunately there isn't a 'one size fits all' solution but hopefully the advice presented here will make rockets more effective in your Longbow 2 missions.

Credit and thanks go to Floydii (Discord) for finding SimHQ posts and additional testing and to SimHQ for hosting these older discussions.

Good hunting!