VOGONS


First post, by fnick50

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Hello,

I been working on Personal Deskmate 2 and 3. The Tandy 1000 Personal Computers sold by Radio Shack between 1987-1990 came with deskmate OS. I would like to list some issues that I can't get working in these versions.

Personal Deskmate 3

  • Not Working: Tandy Dac Emulation

    Attempts: Set Soundblaster to all options, Set Tandy Sound System=True, Reduced CPU Cycles. Deskmate 3 will not run with CPU=Tandy, so I couldn't try that. Deskmate 3 runs with a booted version of dos ( I use version 6.22 with boot image command "C:\boot -L C", once booted I run desk.exe at prompt ) and CPU set to VGA. So far that's the only way to boot Dmate3, will not boot thru dosbox / freedos version of dos.
    Trying to play a file with either Sound.pdm or Music.pdm application, Deskmate stops responding, and must close dosbox and restart.

Personal Deskmate 2

  • Not Working: Functions in menu [ FILE F2 ] DELETE FILE, COPY FILE
    [ DIRECTORY F3 ] DELETE DIRECTORY, CHANGE DIRECTORY.
    Seems Dmate2 will not delete a directory or file and can't change directory from the current one or copy a file. The Windows Explorer shell or dos command line can be a work around for deleting and copying files.

    Attempts: SET COMSPEC=PATHS A & C and different command files from DOS 2.11 COMMAND.COM and FREEDOS COMMAND.COM. The above attempt was suggested in this post :
    Tandy 1000 HX Emulation

    Buggy: Paint.pdm when using the text tool can be alittle buggy with cursor jumping to far right corner or disappearing with a few double clicks comes backs and also addressed in other post F12 key to exit out of canvas doesn't function.

Out of the list of above, The most important seems to be getting the
DAC Emulation working in PERSONAL DESKMATE 3.0, that would make the program fully functional and my goal in this discussion.

Any help is appreciated,
fnick50

Reply 2 of 18, by fnick50

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Hey Wd,

I remember reading the work you did with rx9 with the deskmate 2.

Well I checked to see if there was any setting for sound in setup, or a different driver by searching google. I didn't find much.

I am going to try to find out how deskmate 3 accesses DAC, and to see if it can be directed to bios (int 15). I going to surf the internet, to see what I can find.

It's great having deskmate 2 & 3 run in dosbox

😁

Reply 3 of 18, by fnick50

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Hey,

I found a document while surfing explaining exactly how Tandy Deskmate accesses the DAC from bios. I can't figure it out, but if anyone has time to take a look at the document I think it could help get closer to a solution.

From what I read it seems like (int15) and the bios are used to produce sound for Deskmate 3.

I attached the file, it is called TANDAC.DOC

Here is a section on Page 5 of the document talking about it :

" The BIOS provides access to the DAC on Tandy's that have the chip, using Int 1Ah. This is the easiest way to program the chip. The BIOS announces completion of a sound request by calling out to Int 15h. "

There also a discussion going on about the DAC Chip used in Tandy but I wouldn't know what to ask them to help me.

Thanks for any assistance in advance,

fnick50

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    TANDAC.DOC
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Reply 5 of 18, by fnick50

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The members of the discussion on the DAC Chip, ask me if dosbox can
just turn on tracing when you're about to call sound, then turn it off when done and look at the invalid opcodes/operations attempted?

Reply 7 of 18, by RX9

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Hello all. I haven't posted in a while, and I'm not as technically inclined as some on this board, but I do have a way of getting things done at times via trial and error.

I have DOSBox installed on a WIN_98SE/SB16 computer, and I do have the Tandy Music program working for both DeskMate 2 (PDM2), and DeskMate 3. The latter requires booting DOS (v5.0, in my case) within DOSBox, as stated by fnick50. I also found that it was necessary to use the earliest version of Music.pdm for DM3, and its associated resource files, to get it to work. This is the one dated 1988, and can obtained on TVDog's archive (just Google it). FYI: On my Win_98SE machine, the Music program on PDM2 works just fine as it is.

The Sound program (Sound.pdm), is a different story, however, as no file substitutions seem to make any difference. This is frustrating, as the working Music files (*.sng) are made up of components from the Tandy Sound format (*.snd), suggesting that the basic capability is there. The sound files will load into Sound.pdm, and even allow for compression conversions, but as soon as Play is attempted, the error message "You must have digital sound hardware to perform this function" persists. I have a dump of one of the Tandy Bioses, and I noticed a reference to "PSSJ," Tandy's name for the DAC chip. So I wonder if it is a simple string search/bios check that fails, thereby halting the entire process?

Last edited by RX9 on 2008-07-24, 21:14. Edited 1 time in total.

Reply 8 of 18, by RX9

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I did a little more experimenting and discovered that in order to get the DeskMate Music program to operate per my previous post, it is necessary to set Tandy=true along with Sbtype=none in the DOSBox config file. This is because we want to emulate the original Tandy 3-voice sound rather than the Tandy DAC due to the file substitutions mentioned above. The later version of Music.pdm does a BIOS check as do all versions of Sound.pdm, and will not operate. It's also a good idea to substitute the original versions of the music files themselves (*.sng), as they will play better with the older program. I found that if Sbtype is set to any other value along with Tandy=true, the program does lock up when attempting to play music files, per the earlier posts by fnick50.

Reply 9 of 18, by RX9

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Here's a question that maybe WD could answer. The above solution for the DM Music program is obviously a workaround, by substituting an earlier version that uses the more accommodating Tandy 3-voice emulation. Access to the actual Tandy DAC is still an issue.

I recall that there was a PSSJ (Tandy DAC) expansion card manufactured for a brief period around 1990 that included a driver to add the required BIOS functions. Since DM3 has to be booted within DOSBox anyway, might it be possible to create a config.sys file that includes this driver, and have it load properly with the right DOSBox config setting?

Of course, finding such a card in the first place could be a real challenge, as it was manufactured in very small quantities.

Reply 10 of 18, by wd

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I didn't quite understand the problem yet. You have machine=tandy, right?
That drips down the soundblaster setting to regular sb (or sbpro or so),
and enables tandy sound (if tandy=true or tandy=auto, the latter being the
default setting).
Tandy DAC is probed when tandy=true/auto, but it NEEDS the soundblaster
(as it's using it for simplicity). So disabling soundblaster (sbtype=none)
effectively disables tandy dac.

might it be possible to create a config.sys file that includes this driver

If you boot into dos you can load every driver in config.sys.

Reply 11 of 18, by RX9

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The machine is not set to Tandy, as later versions of DM used VGA. Only the sound is set to Tandy, either 3-voice or DAC depending on the SB type setting. As mentioned by fnick50, DM3 was designed to access the Tandy DAC with a custom BIOS routine, which fails in DOSBox. A workaround is to revert to an earlier version of the Music program that uses 3-voice, but the quality is not as good. No versions of the Sound program work at all. So seeking a solution for DM3 to access the Tandy DAC continues, hence the basis for my previous post.

Reply 12 of 18, by wd

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The machine is not set to Tandy

Be sure to set the sbtype= to regular soundblaster only, as the sb16 needs
hdma ports which clash with some tandy registers. Don't know if this is
an issue here though.

with a custom BIOS routine

Any info on that custom routine? The only thing seems to be the
"You must have digital sound hardware to perform this function"
message, right? Maybe you can disassemble the deskmate thing
to see when it is called.

Reply 13 of 18, by RX9

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WD,
My technical inclination is limited, but I did dig up the following excerpt from the document referenced above by fnick50:

"Note that the above method of initializing the DAC will hang systems without the chip. It is important to detect the chip before initializing it...what the BIOS does is actually to play a very short (10-byte) sound and wait for it to finish. The sound is not even baseline - it's 10 zero bytes."

The master document, Tandac.doc, was written by Jeff Hayes (TVDog), who is renowned for his work with Tandy products. He also has a small utility called SETDAC.COM, which, when run within the DOSBox environment with Tandy DAC enabled, returns the message "Tandy DAC not found."

So, it's beginning to look like just having Tandy DAC compatibility is really not enough for a variety of programs that would use it. They seem to want to know that it exists first, so I guess what I'm doing is suggesting a possible enhancement for a future DOSBox release.

I mentioned in an earlier post that I had detected a reference to the Tandy DAC in a Tandy BIOS. Here it is, for what ever it's worth: "TANDY,PC,PSSJ PBA:01E0"

Thanks very much for your help, WD, even if this turns out to be a dead end.

Reply 14 of 18, by wd

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As i already noted above, the Tandy DAC emulation only works on the bios level (int15).
If the app directly accesses the dac through ports (i've personally only found one
obscure test app that does this) it won't work.

Reply 16 of 18, by RX9

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Here it is, if anyone would like to give it a try

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    Setdac.zip
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