At the heart of the FunKey electronic design is the CPU block, built around the Allwinner V3s chip: We selected this particular chip because it features a built-in 64MB DDR2 DRAM, which is very good as it saves some precious real-estate on the PCB and...
After I convinced myself that the emulator was probably OK, I turned back to the ROM. But after I found yet another ROM image online, and it turned out to be identical to the other three, I have to rule out bad ROM as well. Just as well as I was...
The internet has a dizzying amount of information on EC and pH. After sifting through it, I found some potentially interesting links that are detailed below. The DIY EC meter project that inspired the original EC portion of this design A tutorial on...
The JP-QR701 specifications indicate that it has GB2312 support. I think this also applies to similar products that all seem to come from the same OEM or at least from the same design. Most documentation - especially that found on English-language distributors...
One of the popular chip formats in the 70's and 80's were the ubiquitous EPROMs (Electrically Programmable Read Only Memories). They had very good memory density at the time and were accessible technology for hackers and OEMs alike. They had the advantage...
The Bankswitch cartridge implements the three most common schemes named F8, F6 and F4. The working of the bankswitches is depicted on the table below. Address -Address Lines-- Bankswitch/Bank selected 1 11 8K 16K 32K 2 1098 7654 3210 F8 F6 F4 $1FF0 0001...