SID filter emulation ... perhaps a _tad_ bit too extreme.

Extremely distorted 6581 filter running a combined Waveform arpeggio.

Yes I know this is not strictly accurate but its a fun diversion while i tune it.

Another chip in the wall

pain. MPT-03 mess. pattern recording success. no brain left to explain.

Evolution of sucking

Choice to desolder chips:

1)5$ (and millions of curses)

2)20$ (less curses but a lot of frustration)

3)200$ (And worth every penny.)

CMS (Dual Philips SAA 1099) Recordings

Here's a rarity, carefully sampled for you.

Before the soundblaster, there was the Creative Music System (CMS) (AKA GameBlaster), which contained two Philips SAA 1099 chips.
It pretty much bombed since the OPL2/Adlib was all the rage at that point.

Nevertheless, the thing has some charm. Here are two recordings made on a SB 2.0 CT1350A (with the SAA chips factory installed as legacy option)

Doodle
Loom

More can be found here

8 hours of (why would I buy a flash cart?) later

Cart:



ROM Test:



Note1: this is a bare cart with no battery backup or mapper. Will only run 256 kBit /32KB roms ... which is more than I need for my tests.

Note2: the quote should read please dont _PUT_ your wires in my brain.

Total Stereo separation ATARI 2600 Jr Mod

There are various NTSC 2600 RCA A/V mods out there. Four years ago (note WAAAAAY before I thought of making chipsounds) there were a only a few that I didn't really like since either the mod was mono, or stereo but with huge L+R bleed that didn't really cut it for me.

Four years ago, I also had about zero electronics knowledge, so I hacked the most horrible thing which you can see here:



Instead of feeding the same voltage source to both channels, like in that schematic, I modded it by added TWO 7805's onto an external duck-taped protoboard onto the console itself.
Each of them "feeding" DC component into one of the two TIA audio outputs.
As always I try to bypass AC coupled electrolytic caps - however dangerous this is - to tap in closer to the original signal as possible (in hindsight I should have buffered the signals as well with an opamp).
However ugly it is, it works perfectly for my own taste.

Whats cool about stereo mods? Well to completely isolate effects used by programmers, remember that two channels is not much.

Pacman's horrible intro "tune"
ET's Landing

Notice the TOTAL absence of Background noise. (mp3 encoding did the worst)

Note#2: The Atari Cartridge PCB is from Pixels Past. Build to use 27128 EPROMS (see previous). So fun code can be easily ran and recorded. Dont worry I do have original game carts for Pacman and ET . Like who doesnt.

We had Joy we had fun, We had EPROMs in the sun.

Yes, am all aware that there are proper tools to do this "professionally". But this is way cooler. One and a half day suffice to erase them to 0xFF's.

Way faster than it used to be in the 70's? (debatable), but I otherwise DO miss the ozone layer.

NOTE from this site
"UV-C radiation, which is lethal, is emitted at wavelengths of 200-280 nm. Fortunately, UV-C is completely absorbed by atmospheric ozone and oxygen. Even with severe ozone reduction, UV-C radiation would still be absorbed by the remaining ozone."

EPROMs require UV-C's (according to wikipedia) ... hum .. anyway, 1.5 day to wipe my 27128's is an actual observation.
I have got 20 or so 271282's (salvaged from an arcade board), so this erasing delay is a non issue for my Console/Cartridge development.