Re: HP-75 EPROM programmer Message #8 Posted by Eric Smith on 1 Apr 2011, 1:49 a.m., in response to message #1 by Jeff Davis
There does not appear to be any circuitry to either generate or switch a programming voltage. I suspect that it is a module emulator. HP did their firmware development on various "big" computers, and used commercially available EPROM programmers, so they would have been unlikely to develop their own EPROM programmer specifically for the HP-75.
Based on the number of EPROMs and sockets, it looks like probably emulates the mainframe ROMs in addition to plug-in ROMs. If so, and unless that mainframe ROM emulation can be disabled, it won't be useful with a normal HP-75.
Relatively late in the HP-75 product life, HP introduced the 82713A Plugin Module Simulator, which would be far more useful to a user or developer than this device which was intended for internal HP use.
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