On the Multitasking of Sound Cards for
Receiving and Transmitting

Date: Mon, 01 Sep 1997 01:24:46 +0100
To: hsms@tree.net
From:  Steve, Ko0u 
Subject: [HSMS] Wal, I'll be danged...

Just finished trying my SB16 PnP sound board in a 386DX40 with MS_DSP 0.41;
interestingly, it works! There does seem to be some kind of conflict with my
Mouse Systems Tracball on TX (ONLY on transmit; no problem in receive!) as
the mouse slows down considerably; but everything seems to work otherwise!

When MS_DSP fires up, the initialization screen does NOT show the high DMA
at all; only the regular "low" DMA=1 is shown. This may indicate, as Doug,
VE5UF, has been suspecting, that MS_DSP 0.41 does NOT really use the
full-duplex capability of the sound boards.

Another interesting thing (to me, anyway) is that unlike with my 486DX33, I
can leave the base address of the SB16 set to 220h in the SYSTEM.INI file;
the 486DX33 will freeze and require at least warm reboot if the address is
allowed to remain at the PnP configuration manager's chosen address of 220h
(I edit the SYSTEM.INI file by changing the address to something else like
240h; so far, I have not had cause to try to use the SB16 with a Windows
program, and I'm sure that it would not work if I did). This address
conflict is undoubtedly specific to my own machine and few of you will
encounter it.

Now, if only Doug, VE5UF, and I can figure out how to use a pair of 8-bit
sound boards with MS_DSP 0.41 without having to have W95 running...

73, Steve Ko0U/1

Date: Sun, 31 Aug 1997 22:59:09 -0600
To: hsms@tree.net
From:  Doug, VE5UF 
Subject: Re: [HSMS] Wal, I'll be danged...

At 01:24 AM 9/1/97 +0100, Steve Harrison wrote:

>Now, if only Doug, VE5UF, and I can figure out how to use a pair of 8-bit
>sound boards with MS_DSP 0.41 without having to have W95 running...
Steve hasn't heard this one yet:

I'm sure it *is* possible, but I just ran out of sound cards  :( :(
Quite late last evening, I had a SB16 VIBRA card running alongside an 
old ATI card, each in it's own MS_DSP-0.41/DOS7 session, multi-tasked 
under Windows95. Both DOS sessions were full screen and Alt-Tab switched
between them nicely.  I suspect the cpu (a 486SLC2-66) was fairly busy
and I didn't test at sample rates over 8K/sec.  Each instance of MS_DSP
ran from a separate folder containing a copy of MS_DSP.INI along with 
a copy of MS_DSP.EXE

The VIBRA was doing the receive and time shift playback tasks while 
the old ATI sat there transmitting continuously at 2400LPM in the
background.  Each card was using a separate set of I/O addresses and a 
unique IRQ. Both used DMA01 on a shared basis with DMA arbitration 
handled by the motherboard DMA controller.

This type of multi-tasking should be possible using the old Quarterdeck
DOS product which was popular in the early 90s.  Can't remember its name,
but it shipped with the QEMM memory management tools (or vice-versa). 
Windows 95 (or Windows-anything) not required.

Obvious problems and observations:
1. MS_DSP croaks often when just sitting there doing the same thing and
   usually gives a "The Big Bug" error mesage as it goes down.  But
   no matter which instance of MS_DSP fails, it can be readily restarted
   without affecting the healthy one in the least.
2. I had to discontinue testing when I dropped the screwdriver on the ATI
   card and it has gone to the Happy Hunting Ground or wherever such cards
   go after suffering blown pcb tracks.  Guess I'm fortunate the ISA bus
   survived the trauma and maybe next time I'll power down before putting
   in that *last* screw.  Maybe...
3. This is a possible solution to a what is hoped is a short-lived problem
   with Tx/Rx stereo channel flipping.

Fun while it lasted, though.
73, Doug  VE5UF    mailto:dougf@sk.sympatico.ca


Comments: Rein, W6/PA0ZN