For years I noticed affordable Digigram PCX11+ ISA cards available on a famous auction site. They are relatively high-end DSP-based cards for professional audio use. Focus is on Windows, but they offer DOS support, so I eventually decided to take a leap...

Card looks perfectly fine visually, with a separate (shielding?) PCB 1cm above the main PCB. It has two dipswitch blocks, one for I/O address, the other for input impedance and a block of jumpers for IRQ - so no ISA PnP.

I haven't been able to find documentation, but defaults printed on shielding PCB show 0x300 and IRQ 10. I know these are free on my test system (Cx5x86-100, UMC PCI chipset, running MS-DOS 6.22 from a CF card via passive CF-IDE adapter) as my 3Com 3C509B-TP used those resources and worked fine. I removed that and inserted the PCX11+ set to the default settings.

Note that there is a lot of documentation available for the PCX11+/24, which is the PCI version of the card. Great, but not this one.

Now, according to this thread there are DOS drivers for Digigram ISA cards, but I'm not having a huge amount of success with it. I've tried both drivers:

PCX720: system hangs as soon as I try to run PCX_DRV.EXE (generic) or PCX_5S.EXE (specific to PCX11+), regardless of flags used.
PCX0738: PCX_DRV.EXE ? give instructions:

Digigram Dos Driver Command Line Arguments are : I/O address declaration [...] K<i> pcx11+ KA<i> pcx11+ SBA 220 [...] v=<softwar […]
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Digigram Dos Driver Command Line Arguments are :
I/O address declaration
[...]
K<i> pcx11+
KA<i> pcx11+ SBA 220
[...]
v=<software interrupt> (0xf1 is default value)
i=<hardware interrupt>
[...]
x=<KBytes XMS memory size per card>
[...]
Other switches:
[...]
IO: Pcx cards uses I/O access (default)
[...]
Example: Pcx_Drv v=0xf1 i=10 e1=0x700 IO x=512

So I tried PCX_DRV I=10 K1=0x300 X=512

Result:

Downloading routinge. Downloading Xilinx on PCX11 + Downloading file X11P_IO.RBT ..Failed! […]
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Downloading routinge.
Downloading Xilinx on PCX11 +
Downloading file X11P_IO.RBT
..Failed!

Downloading error 103 : PCX3 undefined.
Error #0 : Bad command line parameter. (try ? or help)

Tried various other options, but results remained similar. If I failed to specify correct card type, it just immediately gave:

Error #0 : Bad command line parameter. (try ? or help)

Anyone have any tips here?