Difference between revisions of "Dragon ROM/RAM Cartridge (Rink)"
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Latest revision as of 17:00, 5 August 2014
Overview
These cartridge boards were created as a replacement for the standard 8K ROM cartridge used in the titles published by Dragon Data Ltd. They have been designed to use a single 28 series parallel EEPROM, such as the AT28C64, and will fit inside a Dragon Data Ltd. shell casing.
Two on-board jumpers allow enabling/disabling of write operations and the autostart mechanism.
Use As a ROM Cartridge
The EEPROM can be programmed off-board using any compatible programmer, or whilst fitted to the board - however, this may require a custom programming device.
Two sizes are supported: 8K x 8 (8KB) ROM, or a 32K x 8 (32KB). 16KB EEPROMs may (but probably won't) work depending on their use of the lines A14 and A13.
Use As a RAM Expansion
With a pin-compatible SRAM chip (such as the AS6C62256 from Alliance Semiconductor) installed, the board can operate as a ~16KB RAM expansion - filling the Dragon's cartridge address space 0xC000 - 0xFFEF with usable memory.
As a side benefit of using this, downloaded ROM files can be loaded into this RAM space (where they will believe they are running from a ROM board) from cassette or MP3 player by converting first with DrBinCas. e.g. drbincas ghost.rom GHOSTATK 41952 41952
Example
(Photo of an early board which had a missing resistor. Oops).