Mini EPROM card - 3 miniature memory 3xtension for the Junior Computer

nini EPROM card elektor april 1982 - 4-17 mini EPROM card 3 miniature memory 3xtension for the Junior Computer Phis is an elegant, low-cost olution for Junior Computer iwners seeking a suitable RAM (xtension (to accommodate the lunior BASIC or a large assembler, or instance). At the same time, he board takes up a minimum of pace. ,00k 3 in the series on the Junior :omputer explained how to fetch the hree NMI, RES and I RQ vectors from PROM connected to the bus board and page FF). Appendix 3 gave an xample of this using a 82S23 PROM. ■ 2716 EPROM, however, provides a etter solution, as it is much more traightforward to program (see the EPROM programmer" in the January sue, E-81). The miniature board escribed here is designed to cater for k of EPROM. he circuit diagram for the miniature PROM card is shown in figure 1. The PROM stored in IC2 is addressed by fay of IC1. The memory range corn- rises addresses $F800 . . . $F F F F. Two fire links enable the range to be ac- essed eit...