Finished and verified: SMD replacement boards for Horizon HRD+

As previously mentioned, I’ve been working on an old Horizon HRD+ RAMdisk card for the TI-99/4A. Three of the chips (a 74LS138, a 74LS154, and a 74LS259) had other chips stacked and soldered on top of them, with leads bent out and wires connecting to various places on the board. One chip (the 154) is […]