Tandy 3 Voice Sound - SN76489 ISA Soundcard Project

Discussion about old sound cards, MIDI devices and sound related accessories.

Tandy 3 Voice Sound - SN76489 ISA Soundcard Project

Postby matze79 » 2017-6-01 @ 14:48

Hi,

i wanted to build a lotech Tandy Soundboard, unfortunaly James is not longer selling any boards on his page.
Does anyone own a Spare Board and can Scan both Sides in High Resolution to allow me to build my own ?
EDIT: I'm a idiot.. james already has pictures in high res on his side.
EDIT: Ok backside is missing... :/
i have already all components laying around.. just missing the pcbs.

should not a hard task to reengineer the pcb.

Maybe someone can help me out ?
i can also trade i still have lotech isa compactflash pcbs.
and rs232 to ps/2 converter pcbs.

Thanks

Matthias
Last edited by matze79 on 2018-8-23 @ 13:38, edited 4 times in total.
https://www.dosreloaded.de - The German Retro DOS PC Community
https://www.retroianer.de
matze79
Oldbie
 
Posts: 1171
Joined: 2014-12-12 @ 14:25
Location: Germany, Frankonia

Re: Lotech Tandy Soundboard - Schematic / PCB ?!?

Postby sirlemonhead » 2017-6-02 @ 18:29

Did you contact him? I noticed he's not selling anything at the moment but did he say he's stopped altogether?

Thought he might be receptive to release schematics/files if he's no longer interested in selling PCBs...
User avatar
sirlemonhead
Member
 
Posts: 207
Joined: 2004-9-06 @ 15:16
Location: Ireland

Re: Lotech Tandy Soundboard - Schematic / PCB ?!?

Postby matze79 » 2017-6-05 @ 13:53

yes already did contact him, does not answer anymore.

i found a old schematic.
Tandy-Sound-Adapter-r01.png


but i dont know if its the same version like the pcb from the store.
https://www.dosreloaded.de - The German Retro DOS PC Community
https://www.retroianer.de
matze79
Oldbie
 
Posts: 1171
Joined: 2014-12-12 @ 14:25
Location: Germany, Frankonia

Re: Lotech Tandy Soundboard - Schematic / PCB ?!?

Postby matze79 » 2018-1-20 @ 20:15

tandy.jpg


During my holidays i made some progress..
maybe soon i etch a pcb.

still need to check adress decoder, i'm never have designed one... and have no exact idea how they work.
https://www.dosreloaded.de - The German Retro DOS PC Community
https://www.retroianer.de
matze79
Oldbie
 
Posts: 1171
Joined: 2014-12-12 @ 14:25
Location: Germany, Frankonia

Re: Lotech Tandy Soundboard - get it finished.

Postby dreamblaster » 2018-1-20 @ 20:20

nice !
if you need some help, just pm me
Visit http://www.serdashop.com for retro sound cards, MIDI PCB's, and video converters
OPL2LPT, OPL3LPT, X2, S2, S2P, MCE2VGA, ... many projects ! Have a look, and thanks for your support !
dreamblaster
Oldbie
 
Posts: 622
Joined: 2015-1-18 @ 19:34
Location: Belgium

Re: Lotech Tandy Soundboard - get it finished.

Postby matze79 » 2018-1-21 @ 14:44

Thanks :)

test.jpg


found some spare time.. need a break now :D
https://www.dosreloaded.de - The German Retro DOS PC Community
https://www.retroianer.de
matze79
Oldbie
 
Posts: 1171
Joined: 2014-12-12 @ 14:25
Location: Germany, Frankonia

Re: Lotech Tandy Soundboard - get it finished.

Postby bjt » 2018-1-22 @ 12:59

I have a populated (not working) Lotech Tandy board if it would help you.

Didn't spend too much time troubleshooting it because I have another working board.
You can have it for the price of postage. I suspect it might have a bad via.
User avatar
bjt
Oldbie
 
Posts: 1430
Joined: 2013-2-06 @ 10:40
Location: UK

Re: Lotech Tandy Soundboard - get it finished.

Postby matze79 » 2018-1-22 @ 13:59

Thanks i send you a PM, that would really help me :)

i'm testing some stuff with the Soundchip and a AVR currently (muting noise)
The MCU is only 50 Cent, also why not use one.
Programming is also no problem at all. Just adding a ISP Header.
And a ISP Adapter is today 1-2$ delivered from HK/CN.
https://www.dosreloaded.de - The German Retro DOS PC Community
https://www.retroianer.de
matze79
Oldbie
 
Posts: 1171
Joined: 2014-12-12 @ 14:25
Location: Germany, Frankonia

Re: Lotech Tandy Soundboard - get it finished.

Postby bjwil1991 » 2018-1-22 @ 20:13

bjt wrote:I have a populated (not working) Lotech Tandy board if it would help you.

Didn't spend too much time troubleshooting it because I have another working board.
You can have it for the price of postage. I suspect it might have a bad via.

I purchased one last year on eBay, and it sounds amazing. Guessing you got one on eBay yourself?
C64, WheelWriter 10 Series II QuietWriter 8, Pack-Mate 28 Plus, K6-2/300, Pavilion N3350, iMac G3 & G4, Socket 462, 2x Inspiron 600m, Athlon 64, Dimension 4550 & E510, ThinkPad R40, Presario C700, ASUS X54C, Raspberry Pi B+, 2B-3B+, Custom FX-6300
User avatar
bjwil1991
Oldbie
 
Posts: 1947
Joined: 2013-8-14 @ 03:10
Location: SE, MI USA

Re: Lotech Tandy Soundboard - get it finished.

Postby matze79 » 2018-1-23 @ 15:41

the Schematic above is really outdated, and CE never does anything with that Decoder at C0h.

I redraw something from the Pictures, James seems to use Top Plane as VCC.
As Capacitor on the Image has + connected in the top layer.

tandy_decoder.png


i used the images from lotech cards i found on the net and draw this..
Maybe some one with a Card can confirm it.

My Clock Divider is working fine and also my Tandy Chip is connected right.
The Picture of the ISA Card (Perfboard) is wrong rewired it.

So the only remaining thing is the decoder :)

And here my LanCable WireMess:
messcard.jpg
https://www.dosreloaded.de - The German Retro DOS PC Community
https://www.retroianer.de
matze79
Oldbie
 
Posts: 1171
Joined: 2014-12-12 @ 14:25
Location: Germany, Frankonia

Re: Lotech Tandy Soundboard - get it finished.

Postby matze79 » 2018-1-29 @ 15:57

Adress Decoder is working now, Card is playing Sounds :)

Thanks to everyone helped.

Now i have 2 working Boards.

Now its time to get the Noise on Power up fixed :D
https://www.dosreloaded.de - The German Retro DOS PC Community
https://www.retroianer.de
matze79
Oldbie
 
Posts: 1171
Joined: 2014-12-12 @ 14:25
Location: Germany, Frankonia

Re: Lotech Tandy Soundboard - get it finished.

Postby matze79 » 2018-2-02 @ 11:18

Here a Picture of the working Card:

DSC_0099 (Large).JPG


i working now on getting the Sound IC muted on Boot Up :)
https://www.dosreloaded.de - The German Retro DOS PC Community
https://www.retroianer.de
matze79
Oldbie
 
Posts: 1171
Joined: 2014-12-12 @ 14:25
Location: Germany, Frankonia

Re: Lotech Tandy Soundboard - get it finished.

Postby matze79 » 2018-2-02 @ 15:54

breadboard test for muting 76489 successful.

Added 74HC244 to the perfboard build, allowing me to cut the 76489 from isa bus to send commands with mcu.
Had some issues, but turning down Busspeed to 4.77Mhz fixed them :)

test1.jpg


Tomorrow is MCU Time :D
https://www.dosreloaded.de - The German Retro DOS PC Community
https://www.retroianer.de
matze79
Oldbie
 
Posts: 1171
Joined: 2014-12-12 @ 14:25
Location: Germany, Frankonia

Re: Lotech Tandy Soundboard - get it finished.

Postby Great Hierophant » 2018-2-03 @ 04:47

Great progress, keep up the good work!
http://nerdlypleasures.blogspot.com/ - Nerdly Pleasures - My Retro Gaming, Computing & Tech Blog
User avatar
Great Hierophant
l33t
 
Posts: 2377
Joined: 2003-4-27 @ 08:20

Re: Lotech Tandy Soundboard - get it finished.

Postby matze79 » 2018-2-03 @ 13:27

mcu_tech.jpg


MCU is wired up.

Now its time to get a Idea howto get it work..

Need still to cut off some signals (CE/IOW/etc)

Pass them Trough MCU ? hmm
https://www.dosreloaded.de - The German Retro DOS PC Community
https://www.retroianer.de
matze79
Oldbie
 
Posts: 1171
Joined: 2014-12-12 @ 14:25
Location: Germany, Frankonia

Re: Lotech Tandy Soundboard - get it finished.

Postby matze79 » 2018-2-05 @ 11:07

With MCU passthrough i get timing issues, even if i do use asm hmm.
And another Amp or Transistors to switch off would raise the part count up..

EDIT:
Stupid Idea, content removed.
https://www.dosreloaded.de - The German Retro DOS PC Community
https://www.retroianer.de
matze79
Oldbie
 
Posts: 1171
Joined: 2014-12-12 @ 14:25
Location: Germany, Frankonia

Re: Lotech Tandy Soundboard - get it finished.

Postby matze79 » 2018-3-03 @ 13:34

muting_Ready.jpg

photo_2018-03-03_14-26-05.jpg


Got it!

Muting now works.
The Card is now silent on Bootup.


A RS Flip FLop did not work well for me.
Some BIOS seem to access second DMA Controller, so running the Card on AT (0C0h) can cause the Flip Flop to Trigger on Boot..

I'm using a ATTiny13 now.
https://www.dosreloaded.de - The German Retro DOS PC Community
https://www.retroianer.de
matze79
Oldbie
 
Posts: 1171
Joined: 2014-12-12 @ 14:25
Location: Germany, Frankonia

Re: Lotech Tandy Soundboard - get it finished.

Postby keropi » 2018-3-03 @ 14:18

excellent news!
User avatar
keropi
l33t++
 
Posts: 6649
Joined: 2003-9-08 @ 06:45
Location: Greece

Re: Lotech Tandy Soundboard - get it finished.

Postby dreamblaster » 2018-3-03 @ 19:20

Super news !
Visit http://www.serdashop.com for retro sound cards, MIDI PCB's, and video converters
OPL2LPT, OPL3LPT, X2, S2, S2P, MCE2VGA, ... many projects ! Have a look, and thanks for your support !
dreamblaster
Oldbie
 
Posts: 622
Joined: 2015-1-18 @ 19:34
Location: Belgium

Re: Lotech Tandy Soundboard - get it finished.

Postby matze79 » 2018-3-11 @ 12:08

Current Progress:
tandy_check.jpg


Now i'm Searching a way to reset attiny on System Reset.
https://www.dosreloaded.de - The German Retro DOS PC Community
https://www.retroianer.de
matze79
Oldbie
 
Posts: 1171
Joined: 2014-12-12 @ 14:25
Location: Germany, Frankonia

Next

Return to Sound

Who is online

Users browsing this forum: No registered users and 1 guest