VOGONS


Tandy 3 Voice Sound - SN76489 ISA Soundcard Project

Topic actions

First post, by matze79

User metadata
Rank Oldbie
Rank
Oldbie

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

EDIT:
Hotfixes for LO-Tech Audio Combatible Sound Adapter and R0 and R1 Tandy 3 Voice Boards:

Tandy 3 Voice Sound - SN76489 ISA Soundcard Project

Last edited by matze79 on 2019-10-05, 11:49. Edited 5 times in total.

https://dosreloaded.de - The German Retro DOS PC Community
https://www.retroianer.de - under constructing since ever

Co2 - for a endless Summer

Reply 1 of 390, by sirlemonhead

User metadata
Rank Member
Rank
Member

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...

Reply 2 of 390, by matze79

User metadata
Rank Oldbie
Rank
Oldbie

yes already did contact him, does not answer anymore.

i found a old schematic.

Tandy-Sound-Adapter-r01.png
Filename
Tandy-Sound-Adapter-r01.png
File size
60.24 KiB
Views
4181 views
File license
Fair use/fair dealing exception

but i dont know if its the same version like the pcb from the store.

https://dosreloaded.de - The German Retro DOS PC Community
https://www.retroianer.de - under constructing since ever

Co2 - for a endless Summer

Reply 3 of 390, by matze79

User metadata
Rank Oldbie
Rank
Oldbie
tandy.jpg
Filename
tandy.jpg
File size
154.97 KiB
Views
4090 views
File license
Fair use/fair dealing exception

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://dosreloaded.de - The German Retro DOS PC Community
https://www.retroianer.de - under constructing since ever

Co2 - for a endless Summer

Reply 4 of 390, by dreamblaster

User metadata
Rank Oldbie
Rank
Oldbie

nice !
if you need some help, just pm me

Visit http://www.serdashop.com for retro sound cards, video converters, ...
OPL2LPT, OPL3LPT, X2, S2, S2P, MCE2VGA, ... many projects !
Special vogons LPT bundle : https://www.serdashop.com/Parallel-port-retro-sound-bundle
Thanks for your support !

Reply 5 of 390, by matze79

User metadata
Rank Oldbie
Rank
Oldbie

Thanks 😀

test.jpg
Filename
test.jpg
File size
111.39 KiB
Views
4054 views
File license
Fair use/fair dealing exception

found some spare time.. need a break now 😁

https://dosreloaded.de - The German Retro DOS PC Community
https://www.retroianer.de - under constructing since ever

Co2 - for a endless Summer

Reply 6 of 390, by bjt

User metadata
Rank Oldbie
Rank
Oldbie

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.

Reply 7 of 390, by matze79

User metadata
Rank Oldbie
Rank
Oldbie

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://dosreloaded.de - The German Retro DOS PC Community
https://www.retroianer.de - under constructing since ever

Co2 - for a endless Summer

Reply 8 of 390, by bjwil1991

User metadata
Rank l33t
Rank
l33t
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?

Discord: https://discord.gg/U5dJw7x
Systems from C64 to FX-6300.

Reply 9 of 390, by matze79

User metadata
Rank Oldbie
Rank
Oldbie

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
Filename
tandy_decoder.png
File size
28.52 KiB
Views
3943 views
File license
Fair use/fair dealing exception

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
Filename
messcard.jpg
File size
115.1 KiB
Views
3942 views
File license
Fair use/fair dealing exception

https://dosreloaded.de - The German Retro DOS PC Community
https://www.retroianer.de - under constructing since ever

Co2 - for a endless Summer

Reply 10 of 390, by matze79

User metadata
Rank Oldbie
Rank
Oldbie

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 😁

https://dosreloaded.de - The German Retro DOS PC Community
https://www.retroianer.de - under constructing since ever

Co2 - for a endless Summer

Reply 11 of 390, by matze79

User metadata
Rank Oldbie
Rank
Oldbie

Here a Picture of the working Card:

DSC_0099 (Large).JPG
Filename
DSC_0099 (Large).JPG
File size
476.42 KiB
Views
3819 views
File license
Fair use/fair dealing exception

i working now on getting the Sound IC muted on Boot Up 😀

https://dosreloaded.de - The German Retro DOS PC Community
https://www.retroianer.de - under constructing since ever

Co2 - for a endless Summer

Reply 12 of 390, by matze79

User metadata
Rank Oldbie
Rank
Oldbie

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
Filename
test1.jpg
File size
145.14 KiB
Views
3797 views
File license
Fair use/fair dealing exception

Tomorrow is MCU Time 😁

https://dosreloaded.de - The German Retro DOS PC Community
https://www.retroianer.de - under constructing since ever

Co2 - for a endless Summer

Reply 14 of 390, by matze79

User metadata
Rank Oldbie
Rank
Oldbie
mcu_tech.jpg
Filename
mcu_tech.jpg
File size
152.91 KiB
Views
3743 views
File license
Fair use/fair dealing exception

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://dosreloaded.de - The German Retro DOS PC Community
https://www.retroianer.de - under constructing since ever

Co2 - for a endless Summer

Reply 15 of 390, by matze79

User metadata
Rank Oldbie
Rank
Oldbie

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://dosreloaded.de - The German Retro DOS PC Community
https://www.retroianer.de - under constructing since ever

Co2 - for a endless Summer

Reply 16 of 390, by matze79

User metadata
Rank Oldbie
Rank
Oldbie
muting_Ready.jpg
Filename
muting_Ready.jpg
File size
106.6 KiB
Views
3641 views
File license
Fair use/fair dealing exception
photo_2018-03-03_14-26-05.jpg
Filename
photo_2018-03-03_14-26-05.jpg
File size
133.39 KiB
Views
3641 views
File license
Fair use/fair dealing exception

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://dosreloaded.de - The German Retro DOS PC Community
https://www.retroianer.de - under constructing since ever

Co2 - for a endless Summer

Reply 18 of 390, by dreamblaster

User metadata
Rank Oldbie
Rank
Oldbie

Super news !

Visit http://www.serdashop.com for retro sound cards, video converters, ...
OPL2LPT, OPL3LPT, X2, S2, S2P, MCE2VGA, ... many projects !
Special vogons LPT bundle : https://www.serdashop.com/Parallel-port-retro-sound-bundle
Thanks for your support !

Reply 19 of 390, by matze79

User metadata
Rank Oldbie
Rank
Oldbie

Current Progress:

tandy_check.jpg
Filename
tandy_check.jpg
File size
123.37 KiB
Views
3520 views
File license
Fair use/fair dealing exception

Now i'm Searching a way to reset attiny on System Reset.

https://dosreloaded.de - The German Retro DOS PC Community
https://www.retroianer.de - under constructing since ever

Co2 - for a endless Summer