Windows 1.0 Tandy 2000 builds

The Windows 1.0 Tandy 2000 builds are a trio of early pre-release builds of Windows 1.0 that were demonstrated on the Tandy 2000 Personal Computer throughout mid 1984. Photos of these builds running on said computer were featured in several computer magazines at the time. The main advantage of the Tandy 2000 version of Windows was its color support (thanks to the Model 2000's above-average display adapter), as the PC version was still monochrome at the time.

Earlier build
A photo of this build can be seen in the infobox on the right and was originally published in the 1984-11 issues of 80 Micro and Microcomputing magazines, as well as several issues of Science & Vie Micro magazine from 1985. This build still had the status bar at the top of the screen, along with the system menu and help buttons.

The MS-DOS Executive was called "DOS Window" at the time and had a different menu order. Calculator, Reversi, Color Demo, Puzzle and Sample Applications (later renamed to Template application) were running as well, while Clipboard was minimized. The bottom right corner featured a "trash" icon that can still be found as a leftover in Development Release #5. The 1984-06-12 issue of PC Magazine mentions a "litter icon", which was used for discarding files, similar to the trash can feature on the Macintosh. It seems likely the icon in the photo was used for that purpose, before the feature was removed sometime between these three builds and DR5. The Clipboard icon is also slightly different than in DR5. The labels on the squares in Puzzle application sit lower than in DR5, as do labels on the buttons in Calculator. Reversi's disks are still square in shape, while they are round in DR5.

DOS Window is displaying the list of files on the A: drive (floppy disk). Applications resources are stored in separate files, like in DR5, but the executable extension is  rather than. This extension has persisted in, which is a special system application that hosts DOS applications running under Windows in Alpha and later.

This build is likely Development Release #1 or related to it, as the vertical text alignment in the Calculator and split GDI files indicate that it's earlier than the middle build.

File list
 * : Boxes
 * : Calculator
 * : Clipboard
 * : MS-DOS command interpreter, its presence suggests this may have been a bootable demo disk
 * : The display driver configuration file (also in DR5)
 * : The Cursor Routines executable ( in DR5)
 * : Presumably the batch file that starts Windows and all the applications for demo purposes
 * : The display driver ( in DR5)
 * : Presumably the resource file containing system fonts ( files in later builds)
 * : The GDI component of the system, unclear why there are three different executables and what each one does
 * : The kernel executable
 * : The keyboard driver
 * : This file is also present in DR5 and is used by the Resource Compiler
 * : Unknown, a DOS application based on the extension, possibly used to load . DR5 has a symbol table for it  which hints it is indeed a loader for   files
 * : The mouse driver
 * : Puzzle
 * : Reversi
 * : Sample Application, later renamed to Template Application in DR5
 * : DOS Window, later renamed to MS-DOS Executive, though a few internal  strings remain
 * : Unknown, clearly a Windows application, but with no associated resource file, which could mean it's instead a library or a driver.
 * : The system timer driver
 * : The User component of the system

Middle build
This build was demonstrated at a Boston Computer Society general meeting on 1984-06-26. A recording of this meeting was digitized and uploaded to YouTube by the Computer History Museum (the Windows demo starts at 59:20 in the video). It does not appear very different from the earlier build, but the text in the Calculator buttons is now vertically centered. Files  and   are gone, instead there is now only , and   was removed completely. This build is almost certainly Development Release #2 or at least related to it, as the status bar says  and the files are dated towards the end of 1984-06, the latest being   from 1984-06-26, the day of the demo.

Puzzle's icon is a 3x3 grid instead of a 4x4 grid in DR5 and later. This build also features a new cursor when resizing windows, which is different than both earlier and later builds.

File list BOXES  .MOD      3792  6/24/84 BOXES  .RES      1279  6/19/84 CALC   .MOD      7136  6/21/84 CALC   .RES      1310  6/19/84 COMMAND .COM    15480  1/01/80 CONFIG .BIN       234  6/24/84 CURSOR .MOD      2640  6/20/84 DEMO   .BAT        46  6/26/84 DISPLAY .MOD     6000  6/22/84 FONT   .RES     55272  6/07/84 GDI    .MOD     29104  6/24/84 KERNEL .MOD     35120  1/01/80 KEYBOARD.MOD     1360  6/18/84 KEYNAMES.BIN     1552  5/30/84 MB     .EXE      1834  6/07/84 MOUSE  .MOD      1536  6/17/84 PUZZLE .MOD      5216  6/19/84 PUZZLE .RES      1311  6/19/84 REVERSI .MOD     7920  6/25/84 REVERSI .RES     1622  6/20/84 SAMPLE .MOD      1808  6/21/84 SAMPLE .RES      1311  6/22/84 SHELL  .MOD     26496  6/25/84 SHELL  .RES      2197  6/25/84 TIMER  .MOD       448  6/20/84 WINDOWS .MOD    65984  6/24/84 WINDOWS .RES     3309  6/24/84

Later build
The later build is shown in an ad for the Tandy 2000, featuring Bill Gates describing the Model 2000 and various advantages of developing and using Windows on it. The ad was published in 1984-11 and 1984-12 issues of BYTE magazine, and the 1984-11-05 issue of InfoWorld magazine. While it appears very similar to the earlier builds, there are some notable differences which suggest this build is newer than the previous ones.

The status bar at the top from earlier builds appears to have been removed. The icon at the bottom is the Puzzle application seen in earlier builds. DOS Window is again listing files on the A: drive, but this time there are also the following files that are not present in previous builds:,   and. These are likely files of an early version of the Calendar first seen much later in the May Beta, which was then redesigned before the Premiere Edition into a more feature-rich version. It's unknown whether this Calendar is related to the early Calendar application seen in various photos from 1983.

This build is probably either Development Release #3 or #4 because various UI elements place it between the middle build (likely DR2) and DR5.