2 ms·

I couldn't find pictures of a '139 implemented the "normal" way, but here's a 1-of-8 decoder that is: https://www.richis-lab.de/logic20.htm https://www.richis-l

I couldn't find pictures of a '139 implemented the "normal" way, but here's a 1-of-8 decoder that is: https://www.richis-lab.de/logic20.htm https://www.richis-lab.de/logic20.htm The dual-die+decoder EEPROMs reminds me of these quad-die EPROMs: https://www.eevblog.com/forum/chat/identify-these-weird-eproms/msg4678444/ https://www.eevblog.com/forum/chat/identify-these-weird-epro... Are you sure there's not another two 28HC64s on the other side too?

kens 3y ago
Yes, I'm sure there are just two EEPROMs. Someone on Twitter found the datasheet for the module (DPE8M628), which has details: https://www.datasheetarchive.com/datasheet?id=a3c8d65ff60242ab0216d83895511d1d353596&type=M&term=dpe8m628100b https://www.datasheetarchive.com/datasheet?id=a3c8d65ff60242...