This allows replacing a 23C1000 mask rom with a writable flash chip.

Same as FLASH_23C1000 , except fits entirely inside the DIP-28 socket.

23C1000 is used for the system rom in NEC PC-8300, PC-8401, PC-8500, and Cambridge Z88 at least. So this let's you for instance, install a Y2K-patched system rom in PC-8300.

The 32-pin FLASH_23C1000 is more convenient to use, and is usable in most cases. But IF you have a board that can not tolerate having the 4 extra pins hanging off beyond the end of the DIP-28 socket, or if you just want maximum neatness and safety (against the extra pins touching something), then you can use this DIP-28 version. It's just a bit less convenient to hook up to the programmer to write the chip.

NEC PC-8300 and NEC PC-8500 can take the 32-pin version.

NEC PC-8401 should use this DIP-28 version, or else cut pin 1 of the 32-pin version slightly short in order to prevent pin 1 from touching R65.

Accepts any of 3 possible chip packages: sTSOP-32 8x14mm, TSOP-32 8x20mm, PLCC-32 7x9pin. Pictures above show both 20mm TSOP and a PLCC. (old version of the board with diferent silkscreen and slightly different footprint positioning, but it's still the same board)

How to do the legs.

https://gist.github.com/bkw777/52d85d89eeff8445cc667685d05ea94d

Programming

You will need 3 short male-femal dupont extension wires. For instance, peel 3 wires from one of these https://www.amazon.com/dp/B077N643L7

1 - Remove the VCC-/WE jumper.

2 - Move the A16 jumper to /OE.

3 - Place the board in the programmer, 2 rows away from the top, such that pin #1 of the board is in pin #3 of the programmer.

4 - Connect the following with wires. The pin numbers are relative to an imaginary DIP-32 plugged into the programmer:

• VCC to pin 32 (grey wire in picture above)
• /WE to pin 31 (blue wire)
• A16 to pin 2 (orange wire)

Running

1 - Remove all wires

2 - Install a jumper on /VCC & /WE

3 - Move the /OE jumper to A16

4 - Install the board in place of a 23C1000