S/09 The Mighty Micro
MC6809 Processor - 20-bit address bus
Performance and capabilities never before possible are now available to you in the SwTPC/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.
Directly addresses up to 768K of RAM
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
(Source: SwTPC advertisement)