Electronics Youtuber Anders Nielsen’s newest video introduces the Comparatively Common ROM Programmer venture. This Arduino protect enables you to erase and program 27-series electrically-erasable programmable ROMs (EEPROMs), and serves as a substitute for rather more costly off-the-shelf programmers.
The Comparatively Common ROM Programmer comes as an Arduino Uno protect type issue, which implies you want an exterior microcontroller to program the EEPROMs. The protect supplies the 2 high-voltages required to erase and program the EEPROMs. EEPROMs within the 27-series lack a UV window typical of DIP-style EPROMs. As an alternative, they’re electrically erasable.
One choice to drive the protect is to make use of an Arduino Uno. One other is a previous Nielsen venture. The 65duino is a single-board pc based mostly on the 6502 8-bit microprocessor that gives an Uno protect header structure.
Measuring “excessive voltage” rail (📷: YouTube/Anders Nielsen)
This programmer is “Comparatively Common” as a result of it depends on the JEDEC ROM footprints normal to 24-, 28-, and 32-pin DIP-style ROM chips within the 27-series. On this case, excessive voltage ranges from 5 to 27 volts. Nielsen’s design makes use of BJT drivers to supply these voltages on the suitable pins with a precision potentiometer (trim pot) to calibrate the voltage ranges. Whereas the “high-voltage” pins are software-controlled, it is advisable set bodily jumpers based mostly on the chip/package deal dimension for the EEPROM.
This answer is right for anybody who solely must program DIP-style EEPROMs. Different, costlier programmers can program a way more complete vary of gadgets. Nevertheless, as a programmer particular to 27-series EEPROM gadgets it’s a very inexpensive device. There are a number of methods you may add one to your electronics toolbox.
You should buy a pre-soldered SMD equipment for round $9 (with no microcontroller board). Alternatively, Nielsen supplies all the KiCad design information, PCB Gerbers, and meeting information essential to order one from a producer from the Comparatively Common ROM Programmer GitHub repository.