this is my short story about a partially successful attempt to substitute an KEI2001 VFD display with an OLED of same size.
after i had acquired my KEITHLEY 2001, i quickly got the itch to do something about the very dim display. at that time, there was no affordable VFD available, and the two 7001 that i bought for salvaging a good display did not live up to my expectations.

i stumbled across an OLED 256x64 WEX025664DGPP3N00000, which is mechanically very close to the original VFD. actually, it fits quite well into the slightly modified 7001 display frame, so i assume that it would fit into the 2001 frame as well, given that one is willing to hack the frame a little bit. externally, these changes wouldn't be visible, though. TiN had mentioned before that the comms beween main instrument processor and the display would probably not too difficult to decipher, so i went all in and bought
a display, an STM32L432 NUCLEO 32 board, installed an IAR ide, and started to put together some schematics and a layout for a display board.
of course, the project went totally over the top when i got the idea to integrate an I2C interface as well, because then i would replace this annoying passive LCD on my HP6626A as well.
two birds with one stone.
WCGW.

about half a year later, the VFDs for the 2001, formerly known to be unobtanium, became available through an eevblog forum member, who was so kind to sell me two of them.
so, that killed the the "2001" of the project, and i went on to create the display fonts for the LCD of the HP6626A, only to find out that i had screwed the pinout of the I2C connector big time, and that the complete display contraption would never ever fit in between the HP6626's front bezel and the chassis frame. thank you very much.

end of story is what you can see in below pictures. i still have two or three unpopulated p.c.b.s, and there is also a thing on shapeways to self-contain the display in some kind of mounting frame.
