janh@hplsla.HP.COM (Jan Hofland) (12/01/86)
** this is for the ficticious line eater ** I am looking for technical information on the 1750 RAM module. I have seen it advertised locally for $169. The advertisement said it is 512Kbytes in cartridge form for the C64. I would like to find out what the software and hardware interface looks like. Does it use a bank switch technique for addressing 64Kbytes at a time? Or is it 32Kbytes? What address does it use for controlling which bank is active? These questions are based on the assumption that it uses bank switching techniques. Any information about the hardware and software characteristics would be appreciated. Jan Hofland Hewlett Packard Company Lake Stevens Instrument Division 8600 Soper Hill Road Everett, Wa. 98205 (206) 335 2283 ..!hplsla!janh
fred@cbmvax.UUCP (12/10/86)
> I am looking for technical information on the 1750 RAM module. I have > seen it advertised locally for $169. The advertisement said it is > 512Kbytes in cartridge form for the C64. I would like to find out what > the software and hardware interface looks like. > > Does it use a bank switch technique for addressing 64Kbytes at a time? > Or is it 32Kbytes? > What address does it use for controlling which bank is active? The 1750 RAM module is a 512K byte expansion cartridge for the C128. The 1700 RAM module is a 128K byte expansion cartridge for the C128. The 1764 RAM module is a 256K byte expansion cartridge for the C64. Those diffs aside, they all function alike. The expansion RAM is not a contiguous part of the system. It is accessed via instructions to a DMA controller located at $DF00 (IO-2) in the c64/128 I/O block. It features such operations as Fetch, Stash, Swap, and Compare and a variety of addressing modes. The controller will perform these operations at DMA speed, and can operate on blocks as small as 1 byte or as large as 64K. The 1764 (for use on C64's) requires a beefier power supply, which is included. All modules come with a diskette containing demo programs and examples. The 1764 version comes with a RAM DISK utility; the C128 version of the RAM DISK utility will be finished soon. The C128 in CP/M mode already does support the module as a RAM DISK. Whew. That should suffice as a brief summary. Feel free to ask for details via email. -- Fred Bowen uucp: {ihnp4|seismo|caip}!cbmvax!fred arpa: cbmvax!fred@seismo.css.GOV tele: 215 431-9100 Commodore Electronics, Ltd., 1200 Wilson Drive, West Chester, PA, 19380