VOGONS


Reply 20 of 114, by Great Hierophant

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The technical manual can also be found attached to the scans of the Tandy 1000 HX and TX Technical Manuals, found here : ftp://ftp.oldskool.org/pub/tvdog/tandy1000/documents/ The site you linked to had the important pages intact.

C0 and C1 are used by DMA4 in an AT and the card cannot assert any DRQ or DACK signals on the ISA bus, so you may be safe with the limitation that you cannot use Tandy sound and a 16-bit DMA channel at the same time. I am not aware of any program that would possibly use both at the same time. However, if a sound card or other device like a network or a SCSI card made use of DMA channels 5, 6 or 7, then you may hear unwanted sounds from the sound card.

There are two solutions to this issue. First, you could limit the card so that it only responds to C0 and C1 and 1E0 and 1E1. Second, you could use a switch accessible from the back of the card to disable the sound chip when it is not going to be used. Unless someone can find examples of a game that uses C2-C7, I think the first solution would be best and it only requires replacing the 8-bit comparator with a 10-bit comparator, the 74LS460.

There was a Sound Blaster emulator for the PC Speaker and Covox called Virtual Sound Blaster, made by the same guy that wrote TEMU, so if that is possible, emulating the DAC of the Tandy PSSJ should certainly be possible : Sound Blaster Emulator for Dos?

http://nerdlypleasures.blogspot.com/ - Nerdly Pleasures - My Retro Gaming, Computing & Tech Blog

Reply 21 of 114, by carlostex

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First solution is the best for now. I would like to go simple first and then see what we can do step by step.

I think first step by now is to find some one who can design the circuit on an ISA breadboard, place the 3 voice chip natively at C0h at first and get the behaviour of the circuit. There quite a few games that allow Tandy sound + VGA/EGA via command line switches so if the circuit works ok and outputs sound we can at least provide minimal Tandy functionality and then go from there.

Maybe we should go around VCF and Amibay for someone with the right expertise to design us a circuit. Bryce from amibay comes to mind, and there is also Fagear around here, although he might be too busy and is not familiarized with Tandy 1000 systems.

Reply 22 of 114, by Great Hierophant

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My idea in a nutshell :

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I know its a crappy Paint rendition, but it is the best I can do.

http://nerdlypleasures.blogspot.com/ - Nerdly Pleasures - My Retro Gaming, Computing & Tech Blog

Reply 23 of 114, by carlostex

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Great Hierophant wrote:

My idea in a nutshell :

I know its a crappy Paint rendition, but it is the best I can do.

No worries, we know that it should be a relatively simple circuit. All we need is to find someone who can engineer and put it to the test. I'm going to try and contact Bryce at AmiBay. Then i should see if someone is interested at VCF.

Reply 24 of 114, by Great Hierophant

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I have contacted someone at VCF who could do it and they have expressed interest.

http://nerdlypleasures.blogspot.com/ - Nerdly Pleasures - My Retro Gaming, Computing & Tech Blog

Reply 25 of 114, by carlostex

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Great Hierophant wrote:

I have contacted someone at VCF who could do it and they have expressed interest.

Great, i have contacted Bryce but i'm still waiting for an answer.

Reply 26 of 114, by shock__

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Just a small thing ... a replica is something that can barely be distinguished from the original (meaning to drag along all disadvantages and copying the signal routing 1:1). The SSI-2001, as well as my Covox/DSS & GUS PnP projects are compatibles ... or if you want so, clones 😉
This Tandy card would even go as an original design from what I gathered.

Just 2 cents I wanted to add.

Current Project: new GUS PnP compatible soundcard

[Z?]

Reply 27 of 114, by carlostex

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shock__ wrote:

Just a small thing ... a replica is something that can barely be distinguished from the original (meaning to drag along all disadvantages and copying the signal routing 1:1). The SSI-2001, as well as my Covox/DSS & GUS PnP projects are compatibles ... or if you want so, clones 😉
This Tandy card would even go as an original design from what I gathered.

Just 2 cents I wanted to add.

The goal is indeed to build an original design that can provide at least some level of Tandy features on a normal IBM compatible.

I guess the level of goals would be:

1- Provide basic 3 voice sound via true hardware;
2- Provide PSSJ emulation via TSR through a Sound Blaster card;
3- Provide game detection routines via TSR or patch games;
4- Provide BIOS extensions and Tandy graphics modes emulation via TSR;
5- Provide all of the above via hardware; (not realistic and pretty much impossible)

If we ever reach and conclude step 4, i could say we pretty much achieved a miracle. I think even finishing and suceeding on step 1 would be a great achievement.

Reply 28 of 114, by carlostex

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Bryce as answered me and he has made some pertinent questions.

He does agree that indeed this seems possible to do and although he is not an XT or ISA expert, he stated he could design the schematic/circuit and even do prototyping development.

There are 2 gorillas in the room, at least as far as i am concerned:

1- Project funding; due to my situation i can only make a small contribution towards this project, although if my situation improves greatly i could eventually fund it by myself. We could set a fundraiser for the interested and devise a plan to better apply the money. Have some do the design, and then try to prototype it where it is cheaper.

2- How many cards would be built? So far there seems to be very little interess in this, i guess it would rise if we show a working prototype, but at this point only me, Great Hierophant and possibly Beegle would be interested in this. This will make every single card more expensive if the production run is extremely limited. There's probably a couple more people interested as well, but so far i'd say this is a bit disappointing.

Reply 30 of 114, by Beegle

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Confirming my interest.

Out of curiosity, what is the price range of building a working prototype ISA card? (board, chips, components)
I could of course chip in if needed.

The more sound cards, the better.
AdLib documentary : Official Thread
Youtube Channel : The Sound Card Database

Reply 31 of 114, by carlostex

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Beegle wrote:

Confirming my interest.

Out of curiosity, what is the price range of building a working prototype ISA card? (board, chips, components)
I could of course chip in if needed.

According to Bryce from Amibay (who developed the MIF-IPC replica) cost of designing, developing and assembling a prototype should be between 100 and 200€ and supposedly with also including shipping the card between him and me as he does not have an ISA PC to test.

We could also even make this process simpler by maybe having someone like Bryce designing the circuit and then maybe having someone like Fagear actually building a circuit and test it. I don't know if this would cut the cost, maybe manufacturing PCB's in Russia is cheaper than in Germany, but at least it would help logistically.

Reply 32 of 114, by shock__

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PCBs can be produced for very cheap in china, otherwise OSHPark (USA) has a nice offer too, medium price segment but 3 PCBs instead of a single one - one prominent factor is keeping the PCB size within a certain limit.
Depending on how complex your schematic is prototyping could be done on breadboard "hijacking" a waste ISA card.

Pretty hard to give a general answer there tho ... the PAK68/3 I designed cost 300€ for a prototype (with the board being smaller than your usual ISA card) as the parts were expensive and the PCB a 4-layer one.

Current Project: new GUS PnP compatible soundcard

[Z?]

Reply 33 of 114, by PeterLI

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This guy could potentially also design / manufacture. He built the other MIF-IPC-A replica. The only thing I found is that he is not great at communication / replying.

http://www.amibay.com/member.php?9563-n1mr0d

I highly recommend Bryce. He really was a pleasure to work with and very patient (with my errors).

Reply 34 of 114, by pearce_jj

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Hi All,

I run lo-tech.co.uk and have produced a number of ISA boards. I'd be happy to lend a hand to this design and step in with prototyping.

You can see some of my work here: http://www.lo-tech.co.uk/product-category/retro-ibm-pc/

Reply 35 of 114, by carlostex

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Hi James. I think i had contacted you via email to ask you to assemble me an XT-IDE Card a few months ago.

Anyway, good to know you can help us. I suggest that you me and Great Hierophant keep in touch. The fact that you are in the UK will be logistically advantageous.

Reply 36 of 114, by j^aws

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carlostex wrote:
... The goal is indeed to build an original design that can provide at least some level of Tandy features on a normal IBM compat […]
Show full quote

...
The goal is indeed to build an original design that can provide at least some level of Tandy features on a normal IBM compatible.

I guess the level of goals would be:

1- Provide basic 3 voice sound via true hardware;
...

How many games would only point 1 cover, roughly speaking?

I have a passing interest in this. And much like with the Innovation replica, once I here sounds coming out of a card, this interest would likely be definite.

Reply 37 of 114, by Beegle

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j^aws wrote:
carlostex wrote:

1- Provide basic 3 voice sound via true hardware;

How many games would only point 1 cover, roughly speaking?
I have a passing interest in this. And much like with the Innovation replica, once I here sounds coming out of a card, this interest would likely be definite.

Judging from the data available on Mobygames, there are 380+ games that support the Tandy/PCjr 3-voice sound device.
Of course this is an approximation because
a. There have been errors in the mobygames database in the past.
b. Not all games are listed on mobygames.

The more sound cards, the better.
AdLib documentary : Official Thread
Youtube Channel : The Sound Card Database

Reply 38 of 114, by Great Hierophant

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Beegle wrote:
Judging from the data available on Mobygames, there are 380+ games that support the Tandy/PCjr 3-voice sound device. Of course t […]
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j^aws wrote:
carlostex wrote:

1- Provide basic 3 voice sound via true hardware;

How many games would only point 1 cover, roughly speaking?
I have a passing interest in this. And much like with the Innovation replica, once I here sounds coming out of a card, this interest would likely be definite.

Judging from the data available on Mobygames, there are 380+ games that support the Tandy/PCjr 3-voice sound device.
Of course this is an approximation because
a. There have been errors in the mobygames database in the past.
b. Not all games are listed on mobygames.

That a list of DOS games with Tandy 3-voice music support, and it appears to be reasonably comprehensive. Many of them have an install or setup program or a command line switch that allows you to set the graphics and sound devices independently, and they will work with this board. I know how to get the AGI games like King's Quest III and the early SCUMM games like Maniac Mansion working with a board like this. Don't forget that MobyGames counts compilation packs as separate games, so the number of unique games is slightly lower.

Typically, only "big box" DOS games from established commercial publishers like Sierra, Electronic Arts and LucasArts supported Tandy sound. Some developers like Interplay were somewhat late to the PC party and did not have very wide support in their games until the chip had been thoroughly eclipsed. Very, very few shareware games from companies like Apogee or Softdisk ever supported it.

http://nerdlypleasures.blogspot.com/ - Nerdly Pleasures - My Retro Gaming, Computing & Tech Blog

Reply 39 of 114, by carlostex

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We should come out with a list of games that allow to run them with Tandy sound independant of Tandy graphics, via command line switches etc...
Then we should at the same time compile games that support the Tandy sound chip natively on port 1E0h. I believe some SCI0 and SCI1 games should for instance.