lucac81 wrote on 2025-05-16, 08:43:

Hello, I found that i still had the thin client at my parent's house (i took that home from a previous job) installed FreeDOS 1. […]
Show full quote

Hello, I found that i still had the thin client at my parent's house (i took that home from a previous job) installed FreeDOS 1.9 and tried some games, so far so good, then i tried to connect an mt32-pi that i built, and i'm stuck on how to connect things together:
the t5515 has only a DB9 serial port. i saw that mt32-pi supports usb serial cables as long they are null-modem, so tried an usb TTL converter with a db9 port attached but got unexepected midi status on mp32-pi lcd.
Do I need particular hardware to use the serial port for mt-32?
the t5515 has a pci slot, if i take a compatible card, can i use a soundblaster DB15 to midi cable (should have it around at home somewhere)? or i need special hardware too with a soundcard and a gameport?

Are you sure? Parkytowers indicates they originally came with a parallel port.

https://www.parkytowers.me.uk/thin/hp/t5515/

What you need […]
Show full quote

What you need

USB to Serial cable (e.g. this one)
Null modem serial port adapter (e.g. this one)

A new configuration option usb_serial_baud_rate has been introduced. You’ll need to edit the mt32-pi configration file (mt32-pi.cfg). Replace the following line:

usb_serial_baud_rate = 31250

With this:

usb_serial_baud_rate = 38400

The PC serial port can’t run at the standard MIDI baud rate of 31250bps. Instead we tell our mt32-pi to use 38400bps – the closest “PC standard” baud rate.

https://www.jamesfmackenzie.com/2021/07/25/mt … serial-support/

Also, there's SoftMPU needed on the DOS PC.
It can route MPU-401 writes to PC serial port, but only for Real-Mode games I think.

Edited.

Edit: I tried to figure out which chip the "Sabrent CB-DB9P" cable uses.
It might be a Prolific chip, maybe the good old PL2303?
Other possibility is the FTDI FT232RL? Or CH340G?
I'm exactly not sure. Maybe the mt32-pi needs a specific USB serial chip?

Edit: https://github.com/dwhinham/mt32-pi/wiki/MIDI … r-USB-to-serial

Edit:

if i take a compatible card, can i use a soundblaster DB15 to midi cable (should have it around at home somewhere)?

I suppose, but I can't guarantee it.

Normally, things like Gameport, MPU-401 (UART) and OPL3 are not nearly as troublesome as Sound Blaster compatibility.

A PCI soundcard can do that, even under Windows XP in native mode (no SB Pro compatibility).
It's merely Sound Blaster standard that's tricky, since it uses ISA DMA.

The other peripherals merely need i/o ports in ISA address space, and some IRQs (the MPU is on IRQ 2/9).