[geeks] (1) PCIe-ish slot? (2) PCI SATA? (3) eSATA?

[Jonathan Patschke]

On Mon, 5 Aug 2024, Mouse via geeks wrote:

> I thought it was PCIe at first, but it's about 1cm too close to the
> back panel for a PCIe card I have to fit mechanically.  Anyone have
> any guesses what it might be?

This sounds like one of the various audio / MODEM slots that Intel and
AMD invented.  They had names like "Communication and Networking Riser"
and "They had names like "Communication and Networking Riser" and "They
had names like "Communication and Networking Riser" and "Audio/Modem
Riser."

AMR provided USB, PCM audio, and control/power lines for software modems
and a few channels of stereo audio.  CNR added MII so that an Ethernet
PHY could hang off there, too.

These were a common way for vendors of bargain-basement PCs to add
telephony by using only relays, an ADC, and a whole lot of CPU cycles to
do V.34 in software.  People who cared still ran Couriers.

> (The machine is old enough to have an ISA slot; I was surprised to see
> what appeared to be PCIe on the same board as ISA, but it seems it
> isn't actually PCIe.)

It'd be a really rare machine to have both physical PCIe and ISA slots.
I've never seen one, but they are theoretically possible.

There's a community project called the "dISAppointment" to add real ISA
slots to any modern PC which exposes the LPC bus (serialized ISA for
low-bandwidth peripherals), and I helped with work on a similar device
at Centaur long ago to sniff I/O 0x80 for POST codes for use in test
automation.  "dISAppointment" is mostly used for driving old audio cards
on newer hardware.

-- 
Jonathan Patschke
Austin, TX
USA