Hi.

>At 11:40 AM 2/18/1999 David G wrote:
>>
>>. . . The original IBM PC provided only the 4" connector,
and supported
>>only transfers of 8 bits at a time.  The PC/AT added the
second
>>connector so it could transfer 16 bits at a time.
[Although the
>>number of data lines was increased, there was no need to
duplicate the
>>various bus "control" lines.]
>>. . .
>
>
>Just to clarify, the additional connector of the
>16-bit ISA BUS *does* provide additional control
>lines, including the available secondary IRQs and
>DMA lines which are not present in the 8-bit BUS.
>
>Thus, some modems may have 16-bit edge connectors
>to allow access to the IRQs of the secondary PIC,
>such as IRQs 9, 10, and 11.
>
>John Chin


Only for clarifying: IRQ9 is on B04 on 8-bit connector, on
same pin as previous IRQ2. What happened is that PIC1-IRQ2
was used to cascade PIC2, and second irq on PIC2 was
connected to B04 and renamed IRQ9. Sometimes this signal is
named IRQ2/9.
The new IRQ's on the small part of the 16 bit ISA connector
are IRQ10 (D03), IRQ11 (D04), IRQ12 (D05), IRQ14 (D07) and
IRQ15 (D06).
************************************
Javier Vizcaino. Ability Electronics. [log in to unmask]
http://www.automodelismo.com http://ability53.hypermart.net
  Starting point:        (-1)^(-1) = -1
  Applying logarithms: (-1)*ln(-1) = ln(-1)
  Since ln(-1) <> 0, dividing:  -1 = 1     (ln(-1) is
complex, but exists)

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