steptail.com

Does expecting the unexpected make the unexpected the expected?

User Tools

Site Tools


guides:virtual_modem:section_2

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Next revision
Previous revision
guides:virtual_modem:section_2 [2022-12-17 19:52]
omolini [Section 2 - Shopping list]
guides:virtual_modem:section_2 [2025-03-05 16:00] (current)
omolini [Important note about USB-to-Serial adapters and pre-Pentium era computers]
Line 3: Line 3:
 |  **[[https://​ebay.us/​W07zWR|8GB or larger ​ MicroSD memory card]]** \\ {{:​tutorials:​pics:​microsd_32gb.png?​nolink&​150|}} ​ | $5 [[https://​ebay.us/​W07zWR|eBay]] | |  **[[https://​ebay.us/​W07zWR|8GB or larger ​ MicroSD memory card]]** \\ {{:​tutorials:​pics:​microsd_32gb.png?​nolink&​150|}} ​ | $5 [[https://​ebay.us/​W07zWR|eBay]] |
 |  **[[https://​ebay.us/​aUN6Xq|USB Power Adapter]]** \\ {{:​guides:​pics:​usb_power_adapter.png?​nolink&​150|}} ​                | $5 [[https://​ebay.us/​aUN6Xq|eBay]] | |  **[[https://​ebay.us/​aUN6Xq|USB Power Adapter]]** \\ {{:​guides:​pics:​usb_power_adapter.png?​nolink&​150|}} ​                | $5 [[https://​ebay.us/​aUN6Xq|eBay]] |
-|  **[[https://​ebay.us/​QnFezr|Prolific USB-to-Serial adapter]]** \\ {{:​guides:​pics:​usb_to_rs232.png?​nolink&​200|}} ​ | $8 [[https://​ebay.us/​QnFezr|eBay]]. Get the one with the \\ **Prolific chipset** (explanation below). |+|  **[[https://​ebay.us/​QnFezr|Prolific USB-to-Serial adapter]]** \\ {{:​guides:​pics:​usb_to_rs232.png?​nolink&​200|}} ​ | $8 [[https://​ebay.us/​QnFezr|eBay]]. Get the one with the \\ **Prolific chipset** (explanation below). \\ Make sure it is a bi-directional communications cable. |
 |  **[[https://​ebay.us/​aAxPub|Serial RS-232 Null Modem cable FEMALE/​FEMALE]]** or a \\ **[[https://​ebay.us/​C7wul7|Null Modem F/F Adapter]]** \\ {{:​guides:​pics:​null_modem_cable.png?​nolink&​200|}} {{:​guides:​pics:​null_modem_adapter.png?​nolink&​200|}} ​ | $5 [[https://​ebay.us/​b2WT5G|eBay]] | |  **[[https://​ebay.us/​aAxPub|Serial RS-232 Null Modem cable FEMALE/​FEMALE]]** or a \\ **[[https://​ebay.us/​C7wul7|Null Modem F/F Adapter]]** \\ {{:​guides:​pics:​null_modem_cable.png?​nolink&​200|}} {{:​guides:​pics:​null_modem_adapter.png?​nolink&​200|}} ​ | $5 [[https://​ebay.us/​b2WT5G|eBay]] |
 ^ **Total project cost** ^ **~ $38-$53** ^ ^ **Total project cost** ^ **~ $38-$53** ^
Line 10: Line 10:
  
 ===== Important note about USB-to-Serial adapters and pre-Pentium era computers ====== ===== Important note about USB-to-Serial adapters and pre-Pentium era computers ======
-I have found in my testing, that the cheapest USB-to-serial adapters do not fare well with some older, pre-Pentium era computers with certain UART chips. The cheaper "​molded blue plastic"​ USB-to-serial adapters would not work at all with a 386-class system with an **8250** UART, even at 9600 baud. However, it would work fine with my 486 system which had a **16550AF** UART running at 56 kbit/s. If you're unsure which UART chip you have, you can check it easily in DOS 6 by running the MSD tool. In the DOS prompt, type MSD to run the program, go to Com Ports (Press key C) and it will show the UARTs available. ​Commond ​UARTs are **8250, 16450 and 16550**.+I have found in my testing, that the cheapest USB-to-serial adapters do not fare well with some older, pre-Pentium era computers with certain UART chips. The cheaper "​molded blue plastic"​ USB-to-serial adapters would not work at all with a 386-class system with an **8250** UART, even at 9600 baud. However, it would work fine with my 486 system which had a **16550AF** UART running at 56 kbit/s. If you're unsure which UART chip you have, you can check it easily in DOS 6 by running the MSD tool. In the DOS prompt, type MSD to run the program, go to Com Ports (Press key C) and it will show the UARTs available. ​Common ​UARTs are **8250, 16450 and 16550**. If you have a Pentium-class system, it is likely you have the best UART available.
  
-If you are planning on using a 486 or older computer with either a **8250** or a **16450** UART, you can work around this limitation by using a genuine [[https://​ebay.us/​QnFezr|Prolific USB-to-Serial adapter]], or upgrade the computer by adding a serial I/O card with a **16550AF** UART chip. Please note that **8250** and **16450** UARTs will still be limited, and cannot handle much faster transfer speeds than about 9600 bit/s. To verify the chipset ​under Windows 10, plug in the adapter, open up Device Manager. Under "​Ports"​ you will see the Prolific adapter identify as "​Prolific USB-to-Serial Comm Port".+If you are planning on using a 486 or older computer with either a **8250** or a **16450** UART, you can work around this limitation by using a genuine [[https://​ebay.us/​QnFezr|Prolific USB-to-Serial adapter]], or upgrade the computer by adding a serial I/O card with a **16550AF** UART chip. Please note that **8250** and **16450** UARTs will still be limited, and cannot handle much faster transfer speeds than about 9600 bit/s. To verify the chipset ​of your USB-to-serial adapter, plug in the adapter ​to a modern computer, open up Device Manager. Under "​Ports"​ you will see the Prolific adapter identify as "​Prolific USB-to-Serial Comm Port".
 \\ \\
 \\ \\
Line 51: Line 51:
 ==== Get In Touch With Us! ==== ==== Get In Touch With Us! ====
 Share your thoughts and report bugs on Discord. \\ Share your thoughts and report bugs on Discord. \\
-[[https://discord.gg/4w6CpZ8|{{:​images:​social-discord.png?​nolink|}}]] ​+[[https://protoweb.org/discord/​|{{:​images:​social-discord.png?​nolink|}}]] ​
  
  
 {{tag>​Guides Guides:​Networking}} {{tag>​Guides Guides:​Networking}}
  
guides/virtual_modem/section_2.1671306733.txt.gz · Last modified: 2022-12-17 19:52 by omolini