The S/09 version of the SS-50 and SS-30 busses

The most significant change here from the older 6800 version is the inclusion of four additional address lines, allowing up to a megabyte of main memory. Other changes include the dropping of baud-rate signals, alterations to some of the clock and control lines to correspond with 6809 signals, and slightly higher voltages on some of the power supply lines.
  1. *D0 - (complement) data bus line 0
  2. *D1 "
  3. *D2 "
  4. *D3 "
  5. *D4 "
  6. *D5 "
  7. *D6 "
  8. *D7 - (complement) data bus line 7
  9. A15 - address bus line 15
  10. A14 "
  11. A13 "
  12. A12 "
  13. A11 "
  14. A10 "
  15. A9 "
  16. A8 "
  17. A7 "
  18. A6 "
  19. A5 "
  20. A4 "
  21. A3 "
  22. A2 "
  23. A1 "
  24. A0 - address bus line 0
  25. GND power line
  26. GND "
  27. GND "
  28. +8V "
  29. +8V "
  30. +8V "
  31. -16V "
  32. +16V power line
  33. index-slot - prevents backwards insertion
  34. *Memory Ready
  35. *BSY/*NMI - (complement) non-maskable interrupt
  36. *IRQ - (complement) interrupt request
  37. *FIRQ - (complement) fast interrupt request
  38. *Q - (complement) the "quadrature" clock signal
  39. *E - another clock signal
  40. *VMA - (complement) Valid Memory Address
  41. R/*W - Read / (complement) Write
  42. *Reset - (complement) Reset or power-up
  43. BA - Bus Available for DMA
  44. BS - ???
  45. *Halt - (complement) halts the processor
  46. *Bus Req - (complement) bus request
  47. A19 - address bus line 19
  48. A18 "
  49. A17 "
  50. A16 - address bus line 16

The S/09 version of the SS-30 Bus

The I/O slots are addressed starting at $E000, and have 16 bytes each. So there are now four register select lines.
  1. RS2 - register select 2 - like A2
  2. RS3 - register select 2 - like A3
  3. -16V power line
  4. +16V "
  5. GND "
  6. GND power line
  7. index-slot - prevents backwards insertion
  8. *FIRQ/Q
  9. *IRQ - (complement) interrupt request
  10. RS0 - register select 0 - like A0
  11. RS1 - register select 1 - like A1
  12. D0 - data bus line 0
  13. D1 "
  14. D2 "
  15. D3 "
  16. D4 "
  17. D5 "
  18. D6 "
  19. D7 - data bus line 7
  20. E
  21. R/*W - Read / (complement) Write
  22. +8V power line
  23. +8V power line
  24. 1200b - 1200 baud clock signal
  25. 4800b - 4800 "
  26. 300b - 300 "
  27. 9600b - 9600 "
  28. 110b - 110 baud clock signal
  29. *Reset - (complement) Reset or power-up
  30. Board Select

21-Nov-1997
yakowenk@csx.unxc.edu
(remove all "x"s to get a valid address)