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86Box v3.7

July 31, 2022 - written by richardg867

This is the July 2022 update to 86Box, bringing initial suport for dual monitors, performance improvements and bugfixes. As always, you can download 86Box v3.7 from GitHub.

Dual monitors: color and monochrome

86Box v3.7 brings initial support for pairing a CGA, EGA or VGA color video card with a secondary MDA or Hercules monochrome card. This kind of dual-monitor arrangement is possible because CGA/EGA/VGA and MDA/Hercules use different memory and I/O addresses which usually don’t conflict with each other. Some applications are capable of using both cards for display output:

As for newer emulated setups running operating systems such as Windows 98, we have plans to extend this feature to PCI VGA cards in the future, since many of those have hardware and software support for multi-monitor operation using multiple cards.

Improving performance by slowing hard disks (no, really)

Another new feature brought by this release is a hard disk speed emulator by new contributor elyosh. You can pick a speed profile when adding or editing an IDE or ESDI hard disk on the Settings window, which factors in the rotation speed, physical layout and cache size of an average hard disk from around 1989, 1992, 1994, 1996, 1997, 1998 or 2000; alternatively, the RAM Disk profile maintains the previous instant-access (as fast as the host disk can read/write) behavior. The emulator is currently only available for IDE and ESDI hard disks, but we’re hoping to expand it to other disk types in the future.

But wait, there’s more! It turns out throttling disk speeds has a positive side effect of improving emulation performance (as measured in %), since it effectively spreads the emulated CPU’s I/O workload over time; in other words, the CPU has to work less often than it would with an instant-access disk, reducing or even eliminating the percentage dips that occur due to interrupt bursts during I/O.

With the significant improvement to emulation performance consistency afforded by disk throttling, we’ve opted to set [1997] 5400 RPM as the default IDE and ESDI speed profiles when migrating an emulated machine from a previous version of 86Box to v3.7. As a result of this change, you will see a difference in your setup’s operating system speed and responsiveness if it uses IDE or ESDI hard disks, especially if their images are stored in an SSD, but that’s a worthy sacrifice in the name of consistent performance, especially while running games. You can always restore the old behavior without downgrading 86Box by switching all IDE/ESDI hard disks to the aforementioned RAM Disk speed profile.

Changelog for v3.7

Emulator

User interface

Machines

Hardware

Changelog for v3.7.1

Emulator

User interface

Machines

Hardware