MP-MBA board
The MP-MBA is the mother board in an S/09 system.
It has a set of fifty parallel traces to carry the signals of the SS-50
bus, and another set of thirty for the SS-30 I/O bus.
Probably as a legacy of their earlier systems which were sold as kits,
the traces are each labelled, allowing one to see which signal was on
which line.
The connectors for the SS-50 and SS-30 busses line up neatly, so if
you made a card wide enough, it could plug into both at the same time.
In fact, there is one such board, which plugs into a special slot
at the edge of the MP-MBA: the MP-ID.
Below are lists of the names attached to each line.
MP-MBA SS-50 Signals
- *D0 - (complement) data bus line 0
- *D1 "
- *D2 "
- *D3 "
- *D4 "
- *D5 "
- *D6 "
- *D7 - (complement) data bus line 7
- A15 - address bus line 15
- A14 "
- A13 "
- A12 "
- A11 "
- A10 "
- A9 "
- A8 "
- A7 "
- A6 "
- A5 "
- A4 "
- A3 "
- A2 "
- A1 "
- A0 - address bus line 0
- GND power line
- GND "
- GND "
- +8V "
- +8V "
- +8V "
- -16V "
- +16V power line
- INDEX - no pin - prevents backwards insertion
- *M.RDY
- *BSY/*NMI - (complement) non-maskable interrupt
- *IRQ - (complement) interrupt request
- *FIRQ - (complement) fast interrupt request
- *Q - (complement) the "quadrature" clock signal
- *E - another clock signal
- *VMA - (complement) Valid Memory Address
- R/*W - Read / (complement) Write
- *RESET - (complement) Reset or power-up
- BA - Bus Available for DMA
- BS - ???
- *HALT - (complement) halts the processor
- *BUS REQ - (complement) bus request
- A19
- A18
- A17
- A16
MP-MBA SS-30 Signals
- RS2 - register select 2 - like A2
- RS3 - register select 2 - like A3
- -16V power line
- +16V "
- GND "
- GND power line
- INDEX - no pin - prevents backwards insertion
- *FIRQ/Q
- *IRQ - (complement) interrupt request
- RS0 - register select 0 - like A0
- RS1 - register select 1 - like A1
- D0 - data bus line 0
- D1 "
- D2 "
- D3 "
- D4 "
- D5 "
- D6 "
- D7 - data bus line 7
- E
- R/*W - Read / (complement) Write
- +8V power line
- +8V power line
- 1200b - 1200 baud clock signal
- 4800b - 4800 "
- 300b - 300 "
- 9600b - 9600 "
- 110b - 110 baud clock signal
- *Reset - (complement) Reset or power-up
- Board Select
17-Feb-1999
yakowenk@csx.unxc.edu
(remove all "x"s to get a valid address)