Timex Computer 2048 and AY-3-8910
Internal sound extension for TC2048 can be placed in a
small space between speaker and heatsink. Heatsink should
be shorted about 1.5 cm for this purpose. AY interface is
built on universal board and connected to Z80CPU pins by
the direct connections to DIL40 holder which is placed
between the original CPU holder and the Z80CPU. This way
of mounting still enables easy replacement of defected
Z80's and easy dissasembling of the AY extension.
The design is based on 74LS138 address decoder and
74HC00 NAND gates used for RC generator. RC generator
should generate about 1.7Mhz wave to get proper sound
pitch (check output of 74HC00 pin 6). Additionally you
can use two general purpose I/O 8-bit ports of AY-3-8910
for any purposes like parallel port for printer.
The AY sound module is glued down to the computers
cover and separated by piece of isolating material.
Files for download
- ay_8910_schematic.png 227.4kB (2005-04-10 13:45)
- Schematic, hand made version with list of parts.
- ay_inside_t2048.jpg 45.5kB (2005-04-10 13:45)
- The whole board of Timex Computer 2048 with AY sound interface attached.
- ay_speaker.jpg 24.3kB (2005-04-10 13:45)
- AY board between shortened heatsink and the speaker.
- near_cpu.jpg 25.3kB (2005-04-10 13:45)
- Mounting to the additional holder of the CPU Z80
- AY-3-8910 sound board (ZX Spectrum 128K and Timex 2068 compatibility) with printer slot and IIC magistral.