Any interest in something like this?
I'm aware that a game port on its own is not a sound card, but game ports spent the better part of their existence on sound cards, so something like this might still be a nice add-on for someone who only has an Adlib.
This one is designed around two NE556 dual timer ICs rather than a single (obsolete, expensive and NOS at best) NE558 quad timer IC.
Opinions?
Wow, that looks neat! As far as I'm concerned, that idea is wonderful.
The game interface is/was very interesting, since it essentially is a little ADC (Analogue-Digital Converter).
Quite a few programs used it for other useful tasks beside gaming.
Some people connected temperature sensors to the analogue pins, some build an alarm system using the button pins, etc.
- In BASIC, this was very elegant to do by using the STICK() statement.
So yes, I definitely like the idea of such a new card! 😁
Edit: This is perhaps pure coincidence, but about an hour ago I just finished working on a Game Port releated project.
"Time, it seems, doesn't flow. For some it's fast, for some it's slow.
In what to one race is no time at all, another race can rise and fall..." - The Minstrel
//My video channel//
As you probably noticed, it is heavily inspired by IBM's Analog Input Card.
Compared to the original, I used ceramics capacitors rather than foil capacitors, SIL instead of DIL resistor packs, the two NE556s instead of a single NE558 and shrunk it down to 10cm × 8cm.
Amazingly, the two NE556s combined cost only about ¼ of a single NE558!
This is neat ~
Did you use C0G/NP0 ceramics or something else ? Other types are likely to cause significant linearity errors, due to huge shifts in capacitance with voltage and temperature.
T-04YBSC, a new YMF71x based sound card & Official VOGONS thread about it
Newly made 4MB 60ns 30pin SIMMs ~
mida sa loed ? nagunii aru ei saa 😜
Well, as you can see, I'm not using any specific capacitor type, yet. (It's just computer graphics!)
Basically, the design uses six 10nF capacitors. Two of them are just buffers that keep the 2.5V reference voltage stable, four are timing capacitors.
I figured that the capacitors' exact properties are not particularly important, because the only thing that matters is how long it takes to discharge them from 5V to 2.5V via a resistor, or something along those lines.
If that assumption proves wrong, I can still populate the board with 5mm pin pitch foil capacitors.
There's no huge need to use foil capacitors but you should definitely use C0G/NP0 ceramics in the analog inputs section, then it is guaranteed there are no issues and you can keep the footprints.
Normal X type ceramics and especially Y types (the really cheap parts) have very huge depencence of their capacitance on voltage across them aswell as temperature, losing more than 50% of their capacitance as voltage rises to their rated voltage. Y types lose 90% or even more at their rated voltage ! This produces a non linear curve as the cap seems to charge up even faster as the voltage increases. This will produce strange readings as the joystick position changes from GND end to the VCC end, compressing the result on VCC end. This is why foil capacitors are used in the original circuit, since they do not have such problem. Nowdays you can use C0G/NP0 types rather than films since performance is more or less same while cost being better.
T-04YBSC, a new YMF71x based sound card & Official VOGONS thread about it
Newly made 4MB 60ns 30pin SIMMs ~
mida sa loed ? nagunii aru ei saa 😜
it would be nice if it has a digital input too, for using digital joysticks 😁
https://www.retrokits.de - blog, retro projects, hdd clicker, diy soundcards etc
https://www.retroianer.de - german retro computer board
wrote:There's no huge need to use foil capacitors but you should definitely use C0G/NP0 ceramics in the analog inputs section, then it is guaranteed there are no issues and you can keep the footprints.
Well, in that case I'll use film capacitors. (I can keep the footprints, either way.)
My original plan was to use Z5U bypass capacitors and X7R timing capacitors, but the price difference between 10nF 10% X7R and 10nF 5% foil with compatible footprint is only about 6 cents.
In this context, C0G would cost 2-3 times as much.
wrote:it would be nice if it has a digital input too, for using digital joysticks 😁
Use the prototyping area! 😜 Or the joystick port on an FTL Sound Adapter replica! 😜
Who cares about FTL Soundadapter Gameport, it works with nothing.
Except Dungeon Master, so its just a Piece of Junk.
https://www.retrokits.de - blog, retro projects, hdd clicker, diy soundcards etc
https://www.retroianer.de - german retro computer board
I doubt there are many people using digital joysticks with Adlib cards.
Check out DOSBox Distro:
https://sites.google.com/site/dosboxdistro/ [*]
a lightweight Linux distro (tinycore) which boots off a usb flash drive and goes straight to DOSBox.
Make your dos retrogaming experience portable!
wrote:Who cares about FTL Soundadapter Gameport, it works with nothing.
Except Dungeon Master, so its just a Piece of Junk.
Patching the keyboard interrupt via TSR driver should do the trick. A "mouse" driver would also be an option.
This project has basically been abandoned in favor of a clone of Amstrad's combined Adlib/Gameport card, but I have uploaded the design files to github, anyway, in case anyone is interested.
It is technically complete, but untested.
