Casio R1

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This printing calculator is a similar hybrid than the ANITA MK12. The underlying nucleus is the same than that of the Casio AS-L with the five LSI-chips from Hitachi: HD 3210, HD3211, HD3212, HN3203 and HD 3214. Around this elegant construction the design engineers added a wild over- lay to adapt the nixie display to the timing of the slow printing mecha- nism and to add the two additional keys "total" and "subtotal" to the machine.
Probably, the expense to alter the microprogram in the HN3203 for the printer was to large, so they prefered a hardware solution which nearly doubled the needed pcb-size.

Like the predecessors, the R1 again is realized on two boards:

Casio R1 PCBs

In the unshaded area of the picture one can see the electronics which conforms to the Casio AS-L. In the whole rest there are ICs from many different maufacturers. With others there are als types from the older high-threshold logic (HD 31..) with -24 V supply.