== Technical Specifications ==
Could take memory configurations of Dram types [[4164]] to [[41256]], thus making memory configurations between 64Kb and 512Kb possible.
== Software ==Optional two rom sockets. Each socket could be manually configured for rom 1-15
Dobbertin supplied [[RDOS]] as a optional ROM to use I/O port decoding is the memory expansionsame as Dk'tronics.
A15== Other memory expansions ==0 with all other address bits can be any value.(Use 7fxx for compatibility)
[[dk'tronics 64Kb]]Dobbertin supports all ram configs (c4-ff) as expected.
[[dk'tronics 128Kb]]But, on a 464 with ROMs enabled and config 3 (c3 etc) is chosen we see:
&0000-&3fff: base ram &0000-&3fff &4000-&7fff: upper rom &8000-&bfff: base ram &8000-&cfff &c000-&ffff: upper rom * For the I/O Ports, see [[dk'tronics 256KbStandard Memory Expansions]]. == Software ==
Dobbertin supplied [[SYMBiFACE IIRDOS]]as a optional ROM to use the memory expansion as RAM disc with 444 KB free. They also supplied CP/M 2.2 and Plus with full support of the RAM disc. Other software using this RAM expansion: [[Discology]], Xexor, [[Cosmos]], [[On File]], [[Punishment]], [[Disc'o'Magic]], [[Pyradev]], Alyssa Database, [[CPC Word]], [[FutureOS]] and [[ParaDOS]]. Arnor software like Prowort ([[Protext]]) and [[MAXAM]] II also support the usage of the RAM disc.
Non compatible to the Dobbertin expansion:== Pictures ==
[[Vortex SP 64 - SP 512]]<gallery caption="The Dobbertin ram expansion">Image:Dobbertin ram 3.jpg|Image:Dobbertin ram 4.jpg|Top viewImage:Dobbertin ram 2.jpg|Inside here a version with the optional two roms mounted.Image:Dobbertin ram 1.jpg|Inside top viewImage:Dobbertin ram 1a.jpg|Image:Dobbertin ram 2a.jpg|Image:Dobbertin_512Kb_Top.jpg|Unit TopImage:Dobbertin_512Kb_Bottom.jpg|Unit BottomImage:Dobbertin_512Kb_PCB_Top.jpg|PCB TopImage:Dobbertin_512Kb_PCB_Bottom.jpg|PCB Bottom</gallery>
== Photos == [[Category:Peripherals]] [[Category:Memory expansions]]