Designed for production line and laboratory use, the HP 4145A was the electronics industry's first stand-alone instrument capable of complete DC characterization of semiconductor devices and materials. It stimulates voltage and current-sensitive devices, measures the resulting current and voltage responses, and displays the results in a user-selectable format (graph, list, matrix, or schmoo) on a built-in CRT display.

The photos show an analyzer that has been upgraded with a modern LCD display (NewScope-5 from SIMMCONN Labs) and a “Gotek” floppy emulator to replace its original, proprietary 5.25“ Floppy Drive.

There are several articles/videos on the Internet on retrofitting a “Lotharek” HxC floppy emulator to the analyzer.

Below, the steps to use one of the newer “Goteks” (with the latest 435-based MCU and an OLED display) are outlined. They usually come with “FlashFloppy” already installed.

• Remove the existing 5.25 drive.
• Retrofit a 34-pin IDC connector to the 4145A Floppy cable (covered in the YouTube video below).
• Use a power adapter to connect the Gotek to the 4-pin Molex of the 4145A.
• Connect Pin 6 and Pin 34 on the floppy drive with a jumper wire.
• Format a USB stick for the FAT32 filesystem.
• Load the configuration and binary files for the boot disk onto the USB stick.
• To install the Gotek into the 5.25 bay of the 4145A, either use parts from one of the universal floppy drive adapter kits that can be found on eBay. Or create a custom adapter if you are mechanically skilled.
• Put everything together, turn the instrument on, and it should boot from the Gotek.

Zip-file with the two configuration files and the binary file for the boot disk: Gotek FlashFloppy Files

Credits:

• The boot disk binary file (“DSKA0000.HFE”) can also be obtained from here: https://github.com/exclusivelyhp/4145A.
• Article on putting together the “IMG.CFG” file: http://w6akp.com/projects:hp_4145a_virtual_floppy
• FlashFloppy site: https://github.com/keirf/flashfloppy
• Jared Cabot's video and helpful information with regards to the 1345A display: https://youtu.be/53asomSXkXQ?si=rld6QaL18WURdmna