Category:REU RAM Expansion Units: Difference between revisions
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So far 128, 256, 512, 2048 and 16384 kb (yes, that's 16MB using a ''1541u'') were spotted at the expansion port. | So far 128, 256, 512, 2048 and 16384 kb (yes, that's 16MB using a ''1541u'') were spotted at the expansion port. | ||
The ''REU'' is using up all of the IO-2 area from $DF00 - $DF0F and is mirroring that register range each $20 bytes. Cartridges operating at $DF00 will collide with a ''REU''. Known to work in parallel using a [[port expander]] are [[Retro Replay]] when using a ROM supporting the REU memory config and [[Super Snapshot]] while [[Expert Cartridge]] should work. | The ''REU'' is using up all of the IO-2 area from $DF00 - $DF0F and is mirroring that register range each $20 bytes. Cartridges operating at $DF00 will collide with a ''REU''. Known to work in parallel using a [[port expander]] are [[Retro Replay]] when using a ROM supporting the REU memory config and [[Super Snapshot]] while [[Expert Cartridge]] and [[:Category:Kernal ROM|Kernel ROM]] replacements should also work. | ||
Revision as of 03:57, 27 May 2010
RAM Expansion Unit also known as REU was produced and sold by Commodore. This rather popular device is well covered on the net currently and also emulated in software and hardware (e.g. by the 1541_Ultimate) pretty well. The large Commodore version and the smaller CMD clones both used a CSG8726 as controller chip. The REU is capable of initiating DMA transfers on request allowing storing, fetching and swapping memory with the C64 main memory. The C64 is not able to natively access the REU additional memory and programs need to utilise it especially.
So far 128, 256, 512, 2048 and 16384 kb (yes, that's 16MB using a 1541u) were spotted at the expansion port.
The REU is using up all of the IO-2 area from $DF00 - $DF0F and is mirroring that register range each $20 bytes. Cartridges operating at $DF00 will collide with a REU. Known to work in parallel using a port expander are Retro Replay when using a ROM supporting the REU memory config and Super Snapshot while Expert Cartridge and Kernel ROM replacements should also work.
Weblinks
Pages in category "REU RAM Expansion Units"
The following 3 pages are in this category, out of 3 total.
Media in category "REU RAM Expansion Units"
The following 12 files are in this category, out of 12 total.
1750 1764 Service Schematics HQ.pdf 0 × 0; 2.4 MB
- 1750 1764 Service Schematics.pdf 0 × 0; 255 KB
1750 CMD REU Clone.jpg 508 × 712; 46 KB
1750 REU top.jpg 640 × 480; 21 KB
1764 512kb REU tuff.jpg 2,816 × 2,112; 1.2 MB
- 1764 Ram Expansion Module Users Guide.pdf 0 × 0; 1.86 MB
- 64er SH 1993 01 Produktfuehrer RamExp.pdf 0 × 0; 3.84 MB
CSG8726TechRefDoc-1.0.rar ; 334 KB
- Rec.vhdl ; 8 KB
- Run Issue 88 1991 Dec ABC of REUs.pdf 0 × 0; 1.55 MB
- The Transactor Vol08 02 1987 Sep REU.pdf 0 × 0; 3.72 MB
- The Transactor Vol09 06 1989 Aug REU.pdf 0 × 0; 769 KB
