HAWKING PN580U Data/Fax Modem 56Kbps USB V.90 (down-stream up to 56,000 bps). V.34bis, V.32bis, V.32, V.22bis, V.23, V.22, V.21 Error Correction Protocol V.42 and MNP Class 2 to 4 Data Compression Protocol
Practical Peripherals PM144HC-II 8bit ISA Data/Fax Modem
DCE IG56S-LV INDUSTRIAL MODEM - Click IT Direct
Modem - Wikipedia
Microcom 103603006A DeskPorte 14.4S 14,400 bps Modem New in Box | RecycledGoods.com
PC1414SR Datasheet | Xecom - Datasheetspdf.com
Modem - Wikipedia
Microcom DeskPorte 14.4S 14,400 bps Modem New in Box 103603006A | eBay
Dial Up Modem Sounds, from 300 bps to 56K - YouTube
Microcom 103603006A DeskPorte 14.4S 14,400 bps Modem New in Box | RecycledGoods.com
Amazon.com: Megahertz XJ2144 PC Card 14400/14400bps PCMCIA Gold Series Fax Modem with XJACK, FCC ID: F2M7410005 : Electronics
Can someone enlighten me as to how to work one of these? USR Sportster 14,400bps modem : r/vintagecomputing