Monday, April 27, 2009

SIDs through the ages

Here is a glimpse of some of my collected chips.

While the first one on this picture is dated 83, ive seen a few 1982 ones.
(i must have got one somewhere, probably broken in a bin :)
So they span roughly 10 years in production, in various places in the world
Phillipines, Korea, Hong Kong.

Its hard to find perfectly good working pre-8580 SID chips, as the vast majority of them all seem to have defects in one area or another due to age or power on/off cycle stress. (higher heat dissipation?)

Sometimes its missing voices, missing noises, filter nearly silent, etc.

I try to capture waveforms and run tests the best I can with them. I've got
a perfectly running 6581R4 AR that I baby everyday (not pictured here due to its ugly "blurred in white goo" look)

Tuesday, April 14, 2009

Pokeys under Limestone

Few people know that there are literally thousands of Pokey Chips stored in a limestone cave somewhere in Kansas City. A liquidation company bought truckloads of mint unopened ATARI carts, and among these is the ATARI 7800 version of Ballblazer.

While I didn't feel like ripping apart a perfectly good mint unopened box, I nevertheless scourged through my cartridge collection and opened mine for fun. The third photo shows the desoldered Pokey chip, under the one I got NOS from a dealer (note the manufacturing dates - 5 years apart).

Next I placed the salvaged '87 pokey on my protoboard and played it the Ballblazer title track through it. Love those fat basses.

NOTE1, The ATARI 400/800 (home computer) has a native pokey chip, and the Ballblazer title sounds exactly (to my ears) as it does on the 7800 Cart, its logical to assume that the LucarFilm Games authors didn't want to alter their composition by only using 7800's native TIA chip... but did it justify adding a chip to the cart which would boost production costs a lot? if someone has some info on this i would be curious to know.

NOTE2, the other 7800 Game cart that contained a Pokey chip is Commando, but its not available in the cave.







Tuesday, April 7, 2009

That ____ VIC-I Noise Pattern

My VIC emulation just gave me a good scare yesterday as I suddenly realized I might have overlooked a crucial detail. Time to get the offwhite box out again and sniff the audio pin's output for something....

OK! I'm convinced my Emulation was right... oh well... better triple check everything










Saturday, April 4, 2009

New Acquisition



Just received my latest toy. A PAL Soundic MPT-03 Console (Clone of an Emerson Arcadia 2001 )

And just inside, a socketed Ceramic Signetics UVI 2637 ... Already got the 9Bit noise pattern from it (and surprise its the SAME as TIA Distortion 8!). But some games generate odd mixed patterns that i'll surely be investigating in the future.