Kc89c72 — Datasheet ((top))
An active-high or active-low reset pin (refer to your specific datasheet revision) used to initialize the device hardware registers.
Sets fixed volumes or enables dynamic envelope modulation for Channels A, B, and C.
Users of the KC89C72 often relied on "Universal" VESA drivers or specific utility disks provided by the board manufacturer to unlock the higher resolutions. This ecosystem highlighted a fragmentation in the early graphics market—while the hardware was capable, the user experience was often defined by the availability of a specific .DRV file. However, for those who configured it correctly, the chip provided a stable and responsive graphical experience that facilitated the transition from the command line to the desktop metaphor. kc89c72 datasheet
Because the original General Instrument and Yamaha variants are no longer in production, the KC89C72 via UTSOURCE serves as an essential component for hardware preservation and custom audio synthesizers. Key Technical Specifications DIP-40 (40-pin dual in-line package). Supply Voltage ( VCCcap V sub cap C cap C end-sub ): Standard 5V TTL level.
The CPU controls data routing by pulsing the (Bus Direction) and BC1 (Bus Control 1) pins. Because the chip has a multiplexed bus, you must pass state transitions sequentially to perform operations: An active-high or active-low reset pin (refer to
The internal register architecture, as detailed in the KC89C72 datasheet, is identical to the AY-3-891x family. There are (R0–R15).
For programming, the internal register map and control procedures described in this document apply directly to the KC89C72. This ecosystem highlighted a fragmentation in the early
Internally, the chip contains three tone channels, a noise generator, mixers, a programmable envelope generator, and three digital-to-analog converters (DACs) to produce the final analog signals. The tone frequency ( f ) for a channel is calculated by the formula f = (Clock Frequency / 16) / Tone Period Value .
The KC89C72 is generally available from specialty electronic component distributors and online marketplaces. Some suppliers, like , list the component with DIP40 and PLCC package types, and report it is often 100% functional and guaranteed . While it might not be stocked by major distributors like Mouser or DigiKey, it is reliably available from these specialty sources.
These original chips are no longer in production, making the KC89C72 a valuable component for the restoration and repair of classic hardware, and for use in new retro-inspired projects. In the retro community, it's well-known that the for the AY-3-8910, and is also interchangeable with Yamaha's related SSG (Software-controlled Sound Generator) chip, the YM2149.
The KC89C72 is housed in a standard package. Below is the absolute pin mapping required when designing printed circuit boards (PCBs) or setting up development environments on breadboards. KC89C72 | In Stock - UTSOURCE.net
