After the collapse of the market for the TI 99/4a, Radio Shack sold many
of the parts (including the keyboard, the internal switching power supply
The TI99/4a is not a switcher. I have both the RS powersupply board and
two TI99/4a (a black one and a grey one) and neither use a switcher!
Now the original ti99/4 with the chicklet keyboard (scarce) did use the
switcher.
Allison