B7094 is a Windows-based emulator for the IBM 7094 mainframe computer from the 1960s.

First of all, note that this is unsigned software. The developer has no wish to pay money to a certificate-granting authority to alter this. This means, at best, that the first time you run one of the executables provided here, you'll get the standard warning from Windows about running untrusted software.

At worst, Windows Defender will be in a mood not to allow you to download the executable(s) at all. There's nothing we can do about this. You might want to wait a while for Defender's malware signature file to be updated, and then try again. We have provided a number of alternatives, one of which might work if the file containing both the 32-bit and the 64-bit executable is blocked: a file containing only the 32-bit executable, and a file containing only the 64-bit executable. Sometimes Defender blocks one, sometimes the other (seldom both at the same time). There's also, as a last resort, a file containing only the source code (the files with the executables also contain the source, and there are extensive instructions on how to install Lazarus/Free Pascal and rebuild from source, for what it's worth).

For the paranoid, there's also a file "SHA-512_checksums.txt" containing checksums generated by the Windows "certutil" command-line utility.

Checksums are listed for the following files:

B7094V34A_32+64.zip
B7094V34A_32.zip
B7094V34A_64.zip
B7094V34A_Src_only.zip
B7094V34A_32+64.tgz
reloc_scripts_X-nix.tgz

The B7094V34A_32+64.zip and B7094V34A_32+64.tgz archives have identical contents; the latter is only provided for the convenience of Linux users who'd like to try out B7094 under Wine but don't happen to have Zip installed. The contents of "reloc_scripts_X-nix.tgz" are described in "B7094ReadMe.pdf", included in the documentation (but that archive can be ignored by most users).

Finally, note that this project is maintained solely at the leisure of its author. Users are welcome to record any bugs or complaints in the GitHub "Issues" list, but there's no guarantee that they'll be addressed in a timely fashion (or at all).

If you're a "casual" user, and running Windows, just:

• Download a B7094V34A_*.zip distribution archive

• Extract it into a new folder

• Run either B7094.32.exe or B7094.64.exe in the created "Bin" sub-folder

• Click on the options displayed to select from the many demonstrations available.

B7094 makes no changes to the Windows registry or any other part of the system other than its install folder. Deleting the distribution archive and the install folder will completely remove B7094 from your system.

There is a YouTube video here that shows the use and operation of B7094 (an earlier release, but the basic operation is the same).

There is also more documentation in the "Docs" sub-folder of the install folder, in the following files:

• B7094ReadMe.pdf started out as this README.md, then ballooned into an illustrated user's manual. That's been converted to a PDF (including the illustrations) and tucked into the Docs subdirectory. The earlier README.md and all its attendant jpgs (as well as a markdown file and jpgs that became "B7094DebuggingExamples.pdf") are preserved in "markdown_archive.zip".

• B7094SourceReadMe.txt lists the source files in the ..\Build\Source sub-folder of the install folder. Describes each window file in some detail, also making it something of a "user's manual". Describes how to install and configure Lazarus/Free Pascal and rebuild the B7094 executables.

• B7094ScripterSyntax.txt describes in detail the command syntax of the EC7 script language.

• B7094SuggestedManuals.txt gives links to some useful manuals on bitsavers and elsewhere.

• B7094DebuggingExamples.pdf gives a couple of simple illustrations of how the facililties in B7094 can be used to perform some (admittedly rudimentary) debugging of programs running on the emulated machine.

• B7094WhatsNew.txt describes the current status and history of the emulator (including its very earliest history).

B7094 running on an ARM-based Mac Mini, via wine 9.0 and the Rosetta 2 x86-to-ARM translator: