== Technical Specifications ==
* Uses I/O Port FFxxh (Write only), ie. only /IORQ, /WR, A15-A8 are decoded. A7..A0 are not decoded, and /RD isn't used, too.* Port usage: Write 8bit unsigned sample data to Port FFxxh. The PCBD/A converter is mono and has only one channel (onesidemixing multiple channels is to be done by software) contains .* The Amdrum software "probably/reportedly" uses port FF50h ... which reportedly "needs to be confirmed though". the FFh in upper 8bit is confirmed, but not sure if software always uses 50h in lower 8bit? The five chipson the single-sided PCB are:
{|{{Prettytable|width: 700px; font-size: 2em;}}
|Ferranti ZN428E-8||8bit DAC||mono one-channel 8bit D/A converter (unsigned samples)
|}
The Amdrum probably uses port #FF50 I/O, needs to be confirmed though.
* [[Media:ZN428.pdf|ZN428 Datasheet]] - 8bit D/A Converter