Editing CVT Avant Stellar

{{infobox dkeyboard
| image name   = Stellar_Cropped.jpg
| manufacturer = [[Creative Vision Technologies]]
| interface    = PS/2
| rollover     = NKRO
}}

== Description ==

The Avant Stellar is a programmable mechanical keyboard that was made by Creative Vision Technologies, Inc., also known as CVT.

== History ==

CVT was the successor company that took over the line of mechanical keyboards from [[Northgate Computer Systems]] after it became defunct in the mid-1990s.  CVT's keyboards included the Avant Prime and Avant Stellar.

The Avant Stellar is the successor to the Northgate OmniKey/Ultra-TP, and the Avant Prime is the successor to the [[Northgate OmniKey/101P]].

== Features ==

The Prime and Stellar have similar design, features and circuitry.  The Stellar is a 117-key keyboard with two rows of F-keys along the left and a separate row of F-keys (which by default act as shifted F-keys) along the top.  The 
Prime is a 105-key keyboard with one row of F-keys along the top.

Like their Northgate predecessors, the CVT Avant keyboards are noted for their durable build quality, use of sought-after Alps keyswitches, and customization features.

The Prime and Stellar are programmable via the keyboard itself and through software.  The user can remap any desired keys to other positions in order to create a custom keyboard layout; and users may also create macros consisting of multiple keystrokes and assign those macros to keys on the keyboard.  The Avant keyboards also allow customization of other features such as the key repeat delay and rate and special key functions.

All of these features can be customized by the user by typing a specific sequence of keystrokes to program each desired feature; and, these features can also be customized through keyboard programming software that runs on a Windows host computer that the keyboard is attached to.

== Hardware ==

The Avant keyboards utilize an Atmel AT89C52 microcontroller, with firmware stored in the controller's internal 8KB flash memory.  The Avant keyboard controllers seem to be read-locked, such that the firmware code cannot be read back out (this is a copy-protection feature of the 89C52 controller chip, which appears to have been used by CVT when programming the firmware into their chips).

Thus, unlike the Northgate keyboards, there are no known CVT Avant keyboard firmware samples available that can be used to program a replacement 89C52 controller if the one in an Avant keyboard stops functioning.

The Avant keyboards also include an FM24C16 2KB EEPROM chip, which holds the keyboard's programming data.  The types of data stored on this chip include:

* Key mapping information for each key on the keyboard
* Macro keystrokes and assigned keys with flags
* Keyboard repeat delay and rate
* Comma/period lock state
* Shift/Ctrl/Alt "sticky" and "lock" modes

== Gallery ==

Pictures of Avant Stellar case and PCB.

<gallery widths=250px heights=187px caption="">
Stellar_Case_Top.jpg              | Top view of Avant Stellar keyboard / case.
Stellar_Case_Bottom.jpg           | Bottom view of Avant Stellar keyboard case.
Stellar_Board_Top.jpg             | Top view of Avant Stellar circuit board.
Stellar_Board_Bottom.jpg          | Bottom view of Avant Stellar circuit board.
</gallery>

== Software ==

CVT offered at least three versions of software for their keyboards.  All three versions are capable, in different ways, of sending keyboard programming data from a DOS/Windows PC to an Avant keyboard, provided the computer has a PS/2 port.  There is no known way to program an Avant keyboard via software through a USB-to-PS/2 converter.

There is also no known way to run any of Avant's software versions inside a virtual machine, because VM host software (e.g. VMWare Workstation) does not allow guest software to directly interact with the i8042 keyboard controller's hardware.

Thus, in order to run any of Avant's software versions, a system must be able to directly run the operating system required by the particular Avant software version.

=== DOS Software (AVANTDWN.EXE) ===

CVT provided a DOS utility, AVANTDWN.EXE, which pushes ("downloads" in CVT's terminology) a set of keyboard programming data to the keyboard.  AVANTDWN can be run manually or via a script.

AVANTDWN is only known to support one command-line parameter, which is the name of the file (in CVT's *.kbd file format) to send to the keyboard.

AVANTDWN.EXE is included in the installation of version 3.10 of CVT's software.

AVANTDWN can be run from a bootable DOS USB stick (e.g. FreeDOS) on an x86/x64 system having a PS/2 port.

=== Software Version 3.10 for Windows 3.x / 9x 16-Bit (avantser.exe and avantps2.exe) ===

[[File:ver_310.png|thumb|CVT Avant Version 3.10 Software]]

This version of CVT's software is a 16-bit Windows program (written in Visual Basic, probably version 4 or 5).  It runs as a GUI application on Windows 95, 98 and probably Me, and lets the user program the keyboard by remapping one key to another, programming a macro keystroke sequence and assigning it to a specified key, and other functions.

Notably, this is the only known software version from CVT that can read ("upload" in CVT's terminology) the programming from an Avant keyboard and allow the user to modify it or save it to a *.kbd file.

This version can also send ("download") the programming from the GUI application to the keyboard, where it is stored permanently in the keyboard's EEPROM chip.

As of 11/2023, this software is available as an [https://web.archive.org/web/20060906222916if_/http://www.cvtinc.com:80/downloads/avant31.exe executable] thanks to the Wayback Machine.

=== Software Version 4.00 for Windows 2000 / XP 32-Bit (Avant.exe) ===

[[File:Ver_400.png|thumb|CVT Avant Version 4.00 Software]]

Around the early 2000s, CVT released version 4.00 of their keyboard programming software, which runs only on Windows 2000 and Windows XP (not Windows NT 4.0 or earlier, and not Windows Vista or any later versions).

When this software version is installed, it replaces two of the Windows keyboard drivers (i8042prt.sys, the i8042 port driver, and kbdclass.sys, the keyboard class driver) with CVT's customized versions of those drivers, which support the ability to program the Avant keyboards through their software.

This software design relies on being updated in order to work with newer Windows versions, but the software was never updated to support Vista or later Windows versions, and so cannot work on those versions, due to driver signing requirements or other incompatibility of the Avant custom drivers with those Windows versions.

The 4.00 software version can send ("download") programming data to the keyboard, but cannot read ("upload") the programming from a keyboard.

As of 11/2023, this software is available as an [https://web.archive.org/web/20060911054427if_/http://www.cvtinc.com:80/downloads/Setup2k.exe executable] thanks to the Wayback Machine.

== See also ==

* [[:File:AvantManual.pdf|User's manual for Avant Stellar and Prime keyboards]]

[[Category:Creative Vision Technologies keyboards]]
[[Category:Vintage keyboards]]
[[Category:List of all keyboards]]