peter%gumby@gumby.UUCP (04/25/86)
Can anyone tell me how difficult/easy it is to add RAM to the Amiga after the first 256K expansion? For instance, are all dynamic ram control signals available on the bus (row select, column select, refresh, ...) or do some signals have to be derived externally? If these signals are available why are commercial expansion board so expensive? With current mail order price using 256K x 1 DRAM it should not cost more than U.S.$170 for 1.5 mega-byte of chips. I'm asking this because my dealer doesn't have the hardware manual in stock and I want to know if I can expand my Amiga to 2 meg myself. peter -------------------------------------------------------------- uucp: ..{allegra|harvard|ihnp4|seismo|ucbvax}!uwvax!gumby!peter arpa: peter@gumby
randy%cbmvax@cbmvax.UUCP (04/26/86)
In article <288@gumby.UUCP> peter@gumby.UUCP (Peter Wu) writes: >Can anyone tell me how difficult/easy it is to add RAM to the >Amiga after the first 256K expansion? > >For instance, are all dynamic ram control signals available >on the bus (row select, column select, refresh, ...) or do >some signals have to be derived externally? The custom chips control/make available the dram control signals -- but ONLY to the first 512k bytes. Beyond that, you have to add your own. >With current mail order price using 256K x 1 DRAM it should not >cost more than U.S.$170 for 1.5 mega-byte of chips. > Add to that the cost of an enclosure, extra power-supply (if needed), plus additional circuitry to allow auto-configuration. And, to add to the Amiga expansion bus, you then have to decide whether to pass the buss along, or not. And so on...including being the first on the block. How expensive was/is IBM expansion memory until 3rd. party boards appeared on the market? -- Randy Weiner -- Commodore Business Machines <<Amiga Technical Support>> uucp: {ihnp4|seismo|caip}!cbmvax!randy arpa: cbmvax!randy@seismo.css.GOV TEL: 215-431-9180