Tag: eeprom

Recreates the Apple Disk II controller card with modern components and selectable 16-sector or 13-sector firmware.

The current CT6502 catalog offered the assembled card for direct ordering on 2026-07-24.

Adds a reprogrammable, four-bank ROM adapter for ROM 0 Apple IIgs systems.

The adapter is currently listed as out of stock. It cannot convert a ROM 0 or ROM 1 Apple IIgs to ROM 3.

Replaces Apple III boot, synchronization, video, and bipolar state-machine ROMs with modern EEPROM carrier boards.

JCM's current Apple III categories listed all fourteen variants on 2026-07-24. Representative boot, sync, video, and bipolar pages showed stock, but availability can differ by part number. These adapters are position-specific replacements, not interchangeable upgrades.

Replaces a 24-pin 2364 ROM with a programmable 27xxx-family EPROM or EEPROM and optionally switches among several ROM images.

The Atari-specific Brewing Academy page exposed an Add to Cart path on 2026-07-24, and the open design includes fabrication files. The assembled adapter is configured for a 2764; other capacities need the documented resistor configuration and optional switches. The open project says only the W27C512 configuration was thoroughly tested. Supply legally obtained, exactly sized ROM images and verify socket orientation.

Adds flexible ROM sizing and the ability to page ROM out for a full 64K of RAM.

Current options include a standard or ZIF socket and optional blank or programmed PROMs. The base kit excludes a ROM. A ZIF release bar can foul a nearby logic chip unless the chip is lowered, the socket is reversed, or the bar is shortened. 28C EEPROM support is described as untested.

Open ROM adapter that selects alternate C64 KERNALs through the RESTORE key and indicates the active bank with an LED.

The open project provides Gerbers, firmware, and programming guidance. Retro Electronics lists an assembled board, cables, LED, and blank 27C256 or W27C512, but its page did not expose a current stock or ordering state on 2026-07-25. Users must program legally obtained ROM images; the seller specifically notes that JiffyDOS and JaffyDOS require licenses.