First post, by harry250

User metadata
Rank Newbie

Hi DOSBox team! I'm really getting into using DOSbox for running all my DOS games collection.

I've got Simon Hradecky's Airline Simulator 2 in "bigbox" on original CD running dual screen via two DOSBox 0.74.3 sessions connected together using the built-in IPX master to client feature - on Windows 10, i7 8700, 16gb RAM, AMD r9 390 card - but Ican't get both sessions running together perfectly.

Here's what's happening at the moment:
When I load two independent DOSBox sessions running Airline Sim 2 independently on each, the FPS are fluid - over 100 FPS on each.
But when the two DOSBox sessions are connected together via the Built in DOSBox IPX feature, adding lines like this to the bottom of the master and client DOSBox configs:


mount c c:\4\AS2
jemmex load frame=e000
loadfix atp


mount c C:\5\AS2
jemmex load frame=e000
loadfix atp

JemmEx is the fix to get this sim running in DOSBox 0.73.

The "master" DOSBox window runs perfectly fluid, 200+ FPS, but there is a noticeable lag in FPS on the client side: only 15 FPS, that sort of thing.
All the client is doing in the sim is slewing from receiving update position heading attitude data from the master, and the master controls how the sim flies.
i.e. you fly it from the master side and the client side follows the master.

When I emailed Simon Hradecky recently about there being a lag in FPS on the client side when using 2 DOSBox sessions connected together using IPX, he said the following :

Simon Hradecky wrote:

I used the IPX driver always under pure DOS, never under Windows, so I have no experience with the Windows implementation. It is well possible, that the Windows implementation of IPX is causing issues here.
The master never computes more than 18 updates per second, regardless how fast the frame rate becomes. All updates are calculated with the PC timer tick (DOS timer), that runs at 18.2 Hertz.
It is possible however, that the slave on Windows has an issue on receiving the broadcasts, gets temporarily stuck and therefore loses the visible frame rate. This could have even worsened with the later Windows versions, as the IPX support has basically ceased decades ago in favor of IP (and due to lack of a reasonable IP implementation on DOS I never made an IP driver), and I recall tremendous problems even with Novell's Netware under Windows (in particular as soon as Windows became 64 bit, then none of the clients worked anymore and data corruption was normal).

Is there an easy fix for this in Windows 10? i.e. turn something off in Windows 10 Networking, that sort of thing?
or could the DOSBox IPX feature be made faster in later releases of DOSBox?

PS. I recently bought on GOG the Falcon3 collection. It was on sale for only 3.75, and I've been using that included version of DOSBox in the Falcon3 GOG installer to run some of my other DOS games and have found it runs games smoother and faster than the DOSBox releases in the Download tab on this site.
Was this a specially done custom version of DOSBox tuned to make Falcon3 GOG run smoothly?