Received my new GQ-4X EEPROM programmer from Canada.

Naturally I forgot the 16-bit adaptor board.

At least it is USB based, which saves me dragging out a computer with a parallel port every time I want to program something.

I performed some test reads, erases and writes using USB power alone and everything worked.

I originally assumed that older EPROMs requiring higher programming voltages would automatically require the external DC supply.

That isn’t quite how the GQ-4X works.

The programmer has its own voltage-generation circuitry for programming devices. The external supply is mainly useful when the USB connection cannot provide enough power, such as through an unpowered hub.

MCUmall’s guidance calls for a centre-positive 2.1 mm supply around 9 V and at least 200 mA when external power is required.

So if I adapt some random old power brick, voltage and plug size are not enough. Polarity gets checked with the multimeter first.

Scissors anyone?

Don’t worry, they’re third-party adaptors.

Eventually I want to use this for Dreamcast and Saturn BIOS work, region modifications, prototype preservation and dumping chips from various boards.

For a first proper test I dumped, erased and reflashed a 486 BIOS chip.

Best of all, the BIOS still worked afterwards.

This could become a very useful little machine.

This is the list of compatible chips with the GQ-4X Programmer. Sure are a lot on there… and here’s where to download the drivers and software to run the GQ-4X.

Sources