Old Apple ][ expansion cards

Namal serial cd .jpg

The Apple serial card designed by David N Anderson for Namal Electronics in 1983 supported not only RS232 but also 20mA loop.

This was one of a range of cards from Namal Electronics, Cambridge, England designed by David Anderson for the Apple ][. Like others from this supplier drivers were alailable to allow printing from CP/M if a Z80 card was installed as well as the native Apple DoS.

Jumpers (at the top of the board) could be used to define handshaking type and interface required. This card used a quad opto isolator to proct the 5 volt logic from the 24v RS232 and to isolate for 20mA loop use.

It stands today as a significant historical artifact reflecting:

• British engineering innovation in American hardware ecosystems,

• The evolution of custom Apple II peripherals in the early 1980s,

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