|Build of Windows 1.0|
Windows 1.xx was a build Compudata shipped (since late 1985-09/early 1985-10) with their first iteration of the Tulip System PC Compact (which had 256Kb RAM and a two 360Kb floppy disk system, later iteration(s) had 512Kb RAM and a ~10,27Mb hard disk system)
The base of this build was compiled on/around 1985-09-03, modified with keyboard-drivers by Compudata on 1985-09-23 and had an updated setup.exe (SET-UP version 1.xx most likely from 1985-09-25 and 1.xy from 1985-09-30). It is unclear if the SET-UP version 1.xx was given out aswell, but since the Windows Upgrade Kit TC 1.00 (from 1986-02) explicit "Windows SETUP, version 1.xx (or 1.xy)" mentioned, we can assume it was indeed.
The applications (from late 1985-08/early 1985-09) were already branded as "1.01" in the About box, while the floppy disc stated as "APPLICATION version 1.xx" instead.
We are still not sure from whom was exactly this "1.xx"-designation, the (original) user guide never mentioned this designation at all, while the Windows Upgrade Kit TC 1.00 mentioned it as "This document describes the way to upgrade your Microsoft Windows version 1.xx program diskettes, supplied with your Tulip pc compact or Tulip pc extend microcomputer."
This build was eventually found by ultrawindows and released to BetaArchive on 2019-03-02. This build contains a
write.dat file in Disk 1, but Compudata didn't ship the Windows Write disk with this build by default and a two-disk update set was required to install the Windows Write component for this build.
The original (from 1985-09) was branded with Compudata logo(s) and came with a comprehensive user guide featuring a lot of screenshots of an earlier build, most likely from 1985-06. A later set (from 1986-01), with identical part numbers, was branded with Tulip Computer logo(s) and came with an updated user guide aswell.
In the Dutch media, Compudata talked not a lot about their first 100% IBM-compatible systems, delivered with this version of Windows, but there were some articles about the Tulip System PC Compact and Advance.
In the newspaper "Trouw" from 1985-05-08  about "Compudata moved completely to the IBM-market", they talked about the reasons and presented the two new personal computers for it
F. Hetzenauer [..] presented two new personal computers, the Tulip Advance and the Tulip Compact. These are not only faster but also cheaper than existing computers that can be connected to IBM equipment— Translated quote from F. Hetzenauer
In the newspaper "NRC Handelsblad" from 1985-07-23 , about "Compudata: company news", they talked about the production plans for the two new personal computers
[..] Compudata, the Tulip System PC Advance and Tulip System PC Compact will go in production in 1985-07 or - at least - in 1985-08 [..]— Translated quote from Compudata: company news
The Personal Computer Magazine  reviewed/tested different machines, like the Commodore 128, Schneider CPC-664 and Tulip PC Advance in their issue 9 (1985-09) from that year
In the newspaper "NRC Handelsblad" from 1986-01-13 , about "Compudata: the profit doubled again", they talked about the introduction and delivery of the two new personal computers from last year
The introduction of the two new personal computers, the Compact and the Extend (also known as the Advance), started with the delivery in late 1985-08 [..]— Translated quote from F. Hetzenauer
In the newspaper "Het Parool" from 1986-01-31  about the "success and the growth plans of Tulip Computers" (they changed the company name from Compudata to Tulip Computers due export-purposes) they talked and referred to this version as a "disappointed success story" (from last year).
In addition to the old Tulip I, the company supplies the Tulip Compact, and later this year the Advance, an industrial design computer that is almost ready in the factory, but still waiting for a reliable operating system— Translated quote from F. Hetzenauer
Tulip PC extend flyer images