Michael J. Mahon wrote:
> Tom Greene wrote:
>> On Oct 22, 2:57 pm, "Michael J. Mahon"
 wrote:
>>> The fact that the original expander presented slots 5 and 7 indicates
>>> that both sets of select lines were decoded and that the system was
>>> compatible with this arrangement.
>>>
>>> That makes the Laser expansion slot more versatile than a
"switched"
>>> slot, since both can be used just by referring to them by slot number.
>>>
>>
>> The Laser slot re-uses a few of the pins (-5V, for one) to carry slot
>> 5 select signals in addition to slot 7, otherwise it is pretty much
>> equivalent to slot 7 on the IIe. The pinout is:
>>
>> 1:     IOSEL slot 7
>> 2-17:  A0-A15
>> 18:    R/W
>> 19:    CSYNC
>> 20:    IOSTB
>> 21:    RDY
>> 22:    DMA
>> 23,24: n/c
>> 25:    +5V
>> 26:    GND
>> 27:    n/c
>> 28:    DEVSEL slot 5
>> 29:    NMI
>> 30:    IRQ
>> 31:    RST
>> 32:    INH
>> 33:    -12V
>> 34:    IOSEL slot 5
>> 35:    3.58M
>> 36:    7M
>> 37:    Q3
>> 38:    Ph1
>> 39:    CPU SYNC
>> 40:    Ph0
>> 41:    DEVSEL slot 7
>> 42-49: D7-D0
>> 50:    +12V
>>
>> And here's the expansion box schematic from the Laser 128 technical
>> manual:
>> http://cowgod.org/apple2/laser128-expansionbox.png
> 
> *Very* interesting!
> 
> So a card that uses -5v won't work if plugged into the side of the
> machine, but will work fine plugged into the expansion box!

And, unless I'm misreading something, +5v is similarly MIA at the computer 
connector.  Or, does that simply mean that the expansion chassis fails to make 
use of it?
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