A collection of EW904x eprom programmer related images.
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Miniature view of the MAX626
circuit with wires and
capacitors attached to it


Larger view of the MAX626
circuit, other side,
with wires attached.


Only earth/ ground error modification wire TL 497 circuit, emitter Q4 to common earth
point on ground of C5


EW904B total component side view, all modifications: I/O290, earth loop correction, TL497 circuit, some pull-up R's, Vpp pull down R's and the A13 modification.
A mess, but works great.


EW904B view zoomed in on the component side, all modifications: I/O290, earth loop correction, TL497 circuit, and A13 modification are visible.


EW904B view zoomed in on the solder side, all modifications: I/O290, earth loop correction, TL497 circuit, and A13 modification


Looking through the window of an early 1702 EPROM


Component side EW904BN board, notice: yellow wire databus diode near mounting bracket, diode changes Vpp, coil oscillation damp components, multiturn pots in place of original pots, and the 220 Ohm A13 pull-up R.

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