arm3.gz        PCB layout (drawfile) of an ARM3 adapter for ARM2 systems
               more info in arm3.txt
autovidc.spk   This is an instruction on how to build a VIDC-enhancer
               for older Archimedes computers A3xx, A4xx and A3000. All
               newer models already include the functionality of this
               enhancement. The enhancement is switched via Aux1 and/or
               an external switch. 
iicalarm.spk   hardware expansion to switch the computer at a given
               time on and off
               more info in iicalarm.txt
optoser.spk    serial port opto isolator construction details
z80card.spk    Z80 expansion card details