HX-40, PX-4

PX-4                                                                 HX-40

COMMENTS

Looking at these 2 units  you'd think they were entirely different machines.  Actually, the only difference is the keyboard.  Epson gave them different designations due to the differing target markets.  The unit on the left is the Epson PX-4, while the unit on the right is the HX-40!  And the only difference is the keyboard which is interchangeable by removing 3 screws from the bottom of the computer and replacing it.  Also, the unit on the right is a prototype code named Pine.

You might also notice the right hand corner of the machines.  That was another option available to both units, you could have numerous option cartridges installed here.  Usually either a cassette as the PX-4 has or a microcassette as the HX-40 was used.  The cassette and printer just pop out and plug in.  There was also a cartridge container that the user could load up and access another program.  A DVM adapter was also available.  

The HX-40 was designed primarily as a Point Of Sale terminal, while the PX-4 was set up as a general purpose computer.

Interestingly enough, these 2 units were introduced at the same time as the PX-8, not before.