Case Photo (42K JPG)

More S09 photos

64 K bytes of RAM memory, one parallel and
two serial I/O ports



128 K bytes of RAM memory, one parallel and
two serial I/O ports


February 1981 prices

Copy of SWTPC Ad (127K JPG)

High resolution open case photo (145K JPG)


Performance and capabilities never before possible are now available to you in the SWTPC S/09 Computer System. The S/09 uses the Motorola MC6809 processor, the most powerful 8-bit general purpose MPU available. It features more addressing modes than other 8-bit MPU's and an optimized consistent instruction set enhanced by powerful 16-bit instructions. This, plus 24 indexing submodes, promote the use of modern programming techniques like position independent code, re-entrancy and recursion.

The 20-bit address bus makes possible direct addressing of up to 768 K of memory without any slow or clumsy processes such as bank switching. RAM memory is designed with independent control and array cards for economical expansion of memory. The DMA and the processor boards can access memory independently for different tasks.

Multiuser capability is "built-in". No additional hardware is required to operate additional terminals. A dynamic memory management system can allocate available RAM in as small as 4 K blocks to the various users or tasks.

The dual-bus motherboard design used in the S/09 makes adding I/O ports to the system quick and economical. I/O address decoding for all I/O slots is supplied with the system. All serial I/O cards may be quickly programmed to run at standard baud rates from 110 to 38,400.

Both multiuser and multitasking/ multiuser operating systems are available for the S/09, BASIC, PASCAL and an Assembler are immediately available. Editor and Debug programs are also available for use in system development.

Michael Holley's SWTPC Collection Home Page