Here's some of the issues I've encountered:
* Mouse synchronization: Since the iPEPS provides a PS2 mouse to the host, which provides relative movements, synching the VNC mouse cursor to the host's notion of where the cursor is gets "interesting". The iPEPS has a mouse calibration/synchronization feature where it will attempt to locate the mouse pointer within the VGA picture. This is a bit of an error prone process and the iPEPS will tell you not to have any motion on the screen or icons in the upper left corner as it tries to find the mouse pointer. Assuming it locates the mouse pointer, the VNC mouse and host mouse can continue to get out of sync as mouse acceleration is not constant or consistent across hosts/OS'. The iPEPS has a button to resync the two by moving both to the upper left corner, but that seems a bit error prone as well. When using RealVNC, you can enable a Single Mouse Mode within the iPEPS where there is no discrepancy between the host mouse and the VNC cursor. The VNC movements are directly translated to relative PS2 movements. This works OK, but requires very low latency, and even then is kind of slow.
* VNC compatibility: The iPEPS' VNC server seems to be lacking in the compatibility dept. Out of the box, I was unable to get OSX's Screen Sharing to even connect, Chicken of the VNC would crash or lockup, and Vine Viewer would crash frequently. The RealVNC client for either Windows or OSX seems to work great. The iPEPS also has the ability to force protocol 3.3 compatibility, and then it seems far more compatible, but I lost the ability to enter Single Mouse Mode.
* Support for random video inputs: the iPEPS does seem to work with SoG and most video inputs, but there have been problems. When connected to an HP 712 machine, it almost works with 1024x768 @60Hz, 70Hz, and 75Hz, either SoG or not. By almost works, I mean it displays fine, but every once in a while seems to lose sync for a moment, and the iPEPS will display "no signal" or similar. This is just a flicker, but still makes it difficult to use. The iPEPS does have a rather extensive ability to modify the VGA sampling parameters, which I have not played with sufficiently yet to know if I can solve the issue that way.
It also would not recognize the output of a SuperMac Spectrum 1152 nubus video card in the IIx, under any output resolution I could select. However, a Radius Precision Color 24X works great.
I look forward to testing it with more obscure video inputs, like the ADB NeXT slab.
Other notes are:
* mouse synchronization is only really supported on various versions of Windows and on Solaris. The Addr FAQ explicitly states it does not work on "MAC", and I can confirm it doesn't work very well on System7. The workaroud is to use the Single Mouse Mode, which requires the RealVNC client.
* On hosts that have decent mouse synchronization support, I've successfully used VNC from iSSH on the iphone and ipad. But, anything that requires the SIngle Mouse Mode does not work well, including Mac OS hosts. HP-UX hosts seem to kinda work. Mostly.
* Key translation from the VNC client to the host varies widely with the VNC client. With RealVNC on OSX, the Command key on your client's keyboard is mapped to the Alt/Option key. To send Cmd in RealVNC, you have to select a menu option, unfortunately.
* And of course no critique of a VNC device would be complete without complaining about VNC: it has high latency, requires relatively high bandwidth, and has the video chunking artifacts. But that's just VNC and is kind of expected when using a VNC device.
Those are the down sides. The up side is, I can use my IIx (and the rest of the machines) from almost anywhere. Despite being restricted to RealVNC and a slow mouse and difficult to use key combos, this really is useful. With the DualAccess model of the iPEPS, you still get to use the console so it is unobtrusive in that way. None of the mouse synchronization or keymapping issues above affect the console. Console access appears to be straight through, with the exception of the iPEPS' on screen display and trapping of configurable hotkeys. Even when the iPEPS doesn't recognize the video input, it is passed through to the console unmolested, so at least the console still works.
Additionally, the iPEPS has support for KVMs in the form of a Host list, which can store video and mouse settings per host, and you can configure hotkey macros the iPEPS will run to automatically switch the KVM to the selected host.
