Popular ROMs offer high-voltage and current drive, sinking as much as 20A at 240VAC. These devices can be found in many appliances, tools, test equipment, power supplies and similar devices powered by line current. Although most devices use the ROMs in their logic-one state, a programmer is a handy device when programming is required.

Figure 1 shows a PROM programmer and status indicator that can be used for popular fusible-link ROMs from manufacturers such as Bust-A-Fuse and Little-ROM. When powered from line current, the programmer immediately shows the status of the ROM chip. Pressing the programme button blows the fusible link, placing the ROM's output in the logic-zero or off state.

PROM programmer (cr) Figure 1: Using this PROM programmer, you can program a variety of popular high-voltage, high-current devices.