Optional two rom sockets. Each socket could be manually configured for rom 1-15
== Software ==I/O port decoding is the same as Dk'tronics.
Dobbertin supplied [[RDOS]] as a optional ROM to use the memory expansionA15=0 with all other address bits can be any value.(Use 7fxx for compatibility)
== Other memory expansions ==Dobbertin supports all ram configs (c4-ff) as expected.
[[dk'tronics 64Kb]]But, on a 464 with ROMs enabled and config 3 (c3 etc) is chosen we see:
[[dk'tronics 128Kb]] &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]].
[[SYMBiFACE II]]== Software ==
Non compatible Dobbertin supplied [[RDOS]] as a optional ROM to use the Dobbertin 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]], [[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.
[[Vortex SP 64 - SP 512]] == Photos Pictures ==
<gallery caption="The Dobbertin ram expansion">
Image:Dobbertin ram 2.jpg|Inside here a version with the optional two roms mounted.
Image:Dobbertin ram 1.jpg|Inside top view
Image:Dobbertin ram 1a.jpg|
Image:Dobbertin ram 2a.jpg|
Image:Dobbertin_512Kb_Top.jpg|Unit Top
Image:Dobbertin_512Kb_Bottom.jpg|Unit Bottom
Image:Dobbertin_512Kb_PCB_Top.jpg|PCB Top
Image:Dobbertin_512Kb_PCB_Bottom.jpg|PCB Bottom
</gallery>
[[Category:Peripherals]] [[Category:Memory expansions]]