Hi all, I've been a lurker of these forums for quite awhile but today I thought I'd ask help from the experts here 😀

I just got a Turtle Beach TBS-2000 ISA sound card (CS4232). As soon as I installed it in my IBM 300PL, it started throwing the POST error "Not enough I/O space available", luckily which I can bypass.
I know the card is alive and working, as I managed to get it initialized and playing sound in Windows and DOS (wave,FM, MPU, ...)

Things I tried unsuccessfully:
- Disabled parallel and serial ports
- Turned on PNP OS resource management
- Changed from 16-bit to 10-bit I/O address decode (this made the POST error go away, but resulted in many wacky resource addresses in Windows.)

Since this a low-level error during POST, I figured there is something going on with the card's EEPROM settings.

So I tried flashing the latest EEPROM provided by Turtle Beach in their v1.5 TBS-2000 drivers (TBS2014.ASM).

When the error wasn't fixed, I used resource.exe to dump the CS4232 IC RAM. It found 3 errors near the beginning of the file (as .ASM):

; Hardware Mapping Data
DB 0FEH ; ***ERROR*** 0x48 ONLY ALLOWED
DB 0FFH ; ***ERROR*** 00 or 08 ONLY
DB 0FFH ; IRQ selection A & B - B=15, A=15
DB 0DFH ; IRQ selection C & D - D=13, C=15
DB 0D7H ; IRQ selection E & F - F=13, E=7
DB 0F6H ; DMA selection A & B - B= 15, A=6
DB 0FBH ; ***ERROR*** Upper Nibble = 0 ONLY

And for comparison, here is what's stored in the TBS-2000 EEPROM:

; Hardware Mapping Data
DB 000H ; 00=4/08=8 peripheral port size, XCTL0/XA2
DB 048H ; RESERVED
DB 075H ; IRQ selection A & B - B= 7, A=5
DB 0B9H ; IRQ selection C & D - D=11, C=9
DB 0FCH ; IRQ selection E & F - F=15, E=12
DB 010H ; DMA selection A & B - B= 1, A=0
DB 003H ; DMA selection C - C=3

That is so strange. Where are those weird addresses coming from? Does anybody know what is going on? Thanks.