Quayle Consulting Inc.

CHARON vs. Open Source

"My VAX is a PC"

A VAX or Alpha can be emulated on a modern computer, which allows the existing operating system (such as VAX/VMS), its software, and all applications to be run without change.  No reprogramming is required.  In fact, the emulated system can be much faster than the original system!

There are two choices for VAX or Alpha emulation:
  1. CHARON-VAX, a product of Stromasys.
  2. Open source emulators, such as SIMH and TS10.
Here are the the advantages (+) and disadvantages (-) of each:

CHARON
+ Commercial-grade product.  Proper operation of VMS and other operating systems are tested for each product release.
+ Certified by HP as being a true emulation of a VAX or Alpha.
+ Support for user's Q-bus hardware is available.
+ Installation, configuration, and migration can be contracted on a turn-key basis from
+ Annual support contracts and periodic product updates are available.
+ DEC/Compaq/HP software licenses can be transferred to the emulated system.
+ User training is available.
+ The "Plus" versions of CHARON-VAX support Accelerated CPU Emulation (ACE), which makes the product up to 4 times faster.
+ SCSI drives are supported, including disk arrays and tapes.

Open Source
+ Can be downloaded from the Internet.
+ User-extensible, since source code is available.
- Existing DEC/Compaq/HP software licenses cannot be used legally on the emulated system.
- Not necessarily licensed for commercial use.
- Installation, configuration, and migration are the responsibility of the user.
- No support for Q-bus hardware.
- VAXeln operation not tested.
- Not certified by HP as being a true emulation of a VAX or Alpha.
- No training or support are available.
- No support for physical devices, especially writing magnetic tapes.

Click here to learn more about CHARON-VAX.  Click here to learn more about CHARON-Alpha.

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