Lotharek's Lair

POKEY chips are very rare these days and extremely hard to obtain or buy...But since there are so many stereo productions out there, I wanted my device to play them too! :-)

And I wanted it NOW!

So, once again, we (Lotharek and AcidMaker) met, and after many hours of discussions, we are proud to introduce:

ACID STEREO Upgrade for all ATARI 8-bit systems!

This upgrade utilizes the original POKEY chip and adds extra functionality implemented inside the FPGA —
a perfect marriage of old-school and modern electronics… because THIS IS THE WAY.

Main Features

Uses the original POKEY chip for SIO routines, POTs, and keyboard functions
Integrates extra 2 POKEYs / 4 COVOX inside the FPGA
Dedicated 32-bit, 384 kHz DAC for superior sound output
Proper audio source mixing:
- PBI and SIO audio are converted from analog to digital via two ADCs
- Mixed digitally inside the FPGA
- Output sent to the DAC for crystal-clear sound
2-layer PCB, slightly larger than the original POKEY
Mono productions are played in stereo with channel interpolation (2 selectable modes)
Stereo productions sound exactly as intended — but with one major improvement:
→ No humming in the speakers from your Atari!

PINOUT:

EXTERNAL DEVICE DEDICATED AUDIO OUTPUTS:

AL - audio left (1)
GND - analog. ground (2)
AR - audio right (3)

NEW MONO AUDIO - for "inside ATARI use" only

MONO output (5)
GND - 4,6

INPUTS:

A4 - addres line (present in many places inside atari - example CPU pin 13) - ONLY AND ONE WIRE TO BE CONNECTED for basic fucntionality (7)
Bell - analog input of GTIA beeps
Dxx - address page for COVOX // pin 9 (D6xx) or pin 7 (D7xx) of 74ls138 chip present at ATARI motherboard
Di2, Di1 - digital inputs /// soon more
SIO - sio audio input
PBI - pbi audio input
GND - common GND