Shared Projects by bradleyb

Adapts an MC5 ROM or RAM module to a chip programmer.

U1: two rows of standard header pins, on the bottom of the board, which go into the programmer.

J1: two rows of 17 individual (cut apart) header pins, on the top of the board. Use an existing MC5 ROM module as a jig for soldering them in place.

Designed to hold one or two 128KB SRAM chips

U1, U2: 128KB SRAM chip, i.e. SRM20100LLM-10. For single chip, omit U2, R2, D4.

D1: not sure. Appears to be marked “800”

D2, D3, D4: MELF diode, Schottky, 20V reverse voltage

C1, C2: 1206 MLCC capacitor, 100nF

R1, R2: 1206 resistor, 100k

BATT1: 3V coin cell, i.e. CR1220. Original battery holder is integrated into the module’s plastic housing

The female connectors are just regular “dupont” style crimp terminals, repurposed. Use the housing from an existing MC5 ROM module as a jig to keep them in place when soldering.

Designed to hold a 128KB (27C010) or 256KB (27C020) EPROM.

For 128KB, short JP1 and JP3.

For 256KB, short JP2 and populate U2. The chip type of U2 is not labeled, but presumed to be an AND gate, i.e. 74HC08, used to make the chip /CE go low when either of the module’s enable lines goes low.

CR1 and CR2 are Schottky diodes, 20V reverse voltage. C1 and C2 are 100nF bypass capacitors

The female connectors are just regular “dupont” style crimp terminals, repurposed. Use the housing from an existing MC5 ROM module as a jig to keep them in place when soldering.

Replacement for the jumper block on Apple’s Super Serial Card for the Apple II. Use round, machined headers for the pins!