== Technical ==
BOS ROM exists at rom slot 6 and is decoded exactly (no repeat).
DFxx is decoded by the Vortex RAM Expansion (for BOS) and uses xx0xxxxx xxxxxxxx xxxxxxxx xxxxxxxx (same as other ROM expansions).
The FBBD port is decoded as: xxxxx0xxx0xxxx0x
This means just 3 bits are decoded for it.
Data written to the vortex RAM doesn't write through to main RAM.
On Reset the BOS rom is activated.
Bits 7 and 6 written to FBBD are ignored. Bit 5 is for enabling the ram expansion. Bit 2,1,0 set the bank.
Bit 3 is documented as enabling and disabling the ROM, but I found it didn't work exactly like that.
If bit 3 is set to 1, and upper ROM is enabled with port 7fxx, then ROM on the Vortex RAM Expansion is enabled in the range &c000-&7fff.
If bit 3 is set to 1, and lower ROM is enabled with port 7fxx, then ROM on the Vortex RAM expansion is enabled in the range &c000-&7fff.
If bit 3 is 0, then normal operation happens. ROM is visible in the range &c000-&7fff only if ROM slot 6 is selected and the upper rom is enabled with port 7fxx. When bit 3 is 0, the rom is not visible in the range &0000-&3fff at any time.
It is possible this part of my (arnoldemu) vortex ram expansion is broken, but all other operation works perfectly and the BOS rom is active at reset time and can be used as normal.
On my (arnoldemu) vortex ram expansion, the bus has the value 0. It seems the vortex is forcing the value on the bus.
== Description ==
A RAM expansions expansion card from made by [[Vortex Computersysteme|Vortex]], mounted between CPC464 CPC 464/664 mainboard and CPU/Gate Array. It won't fit on CPC664, CPC6128the cost-down CPC 464, CPC 6128 or CPC+ boards. The card is not compatible with the standard [[dk'tronics]]-sytle style [[Standard Memory Expansions]].
Sold in different sizes of RAM as '''SP 64''', '''SP 128''', '''SP 256''', '''SP 320''' and '''SP 512'''. Resulting in a maximum RAM size of 576K (64K internal, plus 512K external). The smaller SP64-SP320 versions can be upgraded to SP512 by mounting additional RAM chips in the spare sockets. There is also a cut-down version, '''SP 64/M''', which contains only 64K RAM, no BOS ROM, and which isn't upgradable.
Image:Vortex_PCB_Bottom.jpg|Vortex Expansion (Bottom, scanned)
File:Vortex Memory Expansion Advert (CPC Schneider International, issue 8-1985, page 15).jpg|Advert (CPCI 8-1985)
Image:Leaftlet Front.jpg|SP64 The 520 Concept Leaftlet Front
Image:Leaftlet Inside.jpg|SP64 The 520 Concept Leaftlet Inside
Image:Letter 30-1-86.jpg|Screens Microcomputer Distribution Letter - 30/01/1986
</gallery>
See [[Installing Vortex Expansion RAM]].
== Technical (very incomplete) Manual ==
* This section describes how you can access the RAM of the SP512.* The exact decoding [[Media:Vortex SP 512 Kb (eBOS 1.g. complete or partial0) of I/O port addresses is not confirmed at this timeManual.pdf|RAM Expansions for CPC 464 (Vortex) Manual]] {{DE}} {{PDF}}* The port addresses given are recommended and are those used by B.O.S.[[Media:RAM Expansions for CPC 664 (Vortex) Manual.pdf|RAM Expansions for CPC 664 (Vortex) Manual]] {{DE}} {{PDF}}
I/O port &FBBD* [[Media: Bit Function 7 Unknown 6 Unknown (Discology utility uses it - does it choose Vortex RAM in 32K blocks instead of 64K blocks??) 5 Ramcard Expansions SP64- Ram disabled : When 1, allow mapping byte in 7Fxx to access BANK selected by byte 2..0 SP512 User Handbook (Paging ok 32KEnglish) (Screens Microcomputer Distribution Ltd). When 0, 7Fxx has not effect (note DK'Tronic 64K pdf|RAM Expansions for CPC 464 may work in this case(Screens Microcomputer Distribution Ltd). 4 When 1, disable all internal and external RAM. Reserved for future use 3 Ram expansion - Rom disable when 1 2..0 Used to choose the 64K block of the SP512 to selectManual]] {{EN}} {{PDF}}
I/O port &7F00* [[Media: Bit Function 7 Set to 1 6 1 = make RAM visible in range &8000-&FFFF, Vortex BOS 2.0 = make RAM visible in range &0000-&7FFF 5 Set to 1 to activate SP512Manual. If bit 5 of &FBBD is 1 will select SP512 ram, otherwise select RAM of CPC464pdf|BOS 2. 3 1 = Upper ROM disable, 0 = Upper ROM enable 2 1 = Lower ROM disable, 0 = lower ROM enable 1,0 Screen mode * When bit 5 is 0, then bit 6 is ignored.* When reading, ROM has priority over the RAM. == (Vortex) Manual ==]] {{DE}} {{PDF}}
* [[Media:Vortex SP 512 Kb Vortex_Ext_SPM_-_Memory_mapping_(BOS 1.0DEU) Manual.pdf|Vortex SP 512 Kb (BOS 1.0) ManualMemory mapping]] (pdf) {{DE}} (August 1985)* [[Media:Vortex BOS 2.0 Manual.pdf|Vortex BOS 2.0 Manual]] (pdf) {{DEPDF}} (10.11.1986)* [[Media:Vortex RAM Expansions SP64Vortex_Ext_SPM_-SP512 User Handbook _Principe_d'utilisation_des_cartes_d'extension_RAM_(English) (Screens Microcomputer Distribution LtdFRA).pdf|Principe d'utilisation des cartes d'extension RAM]] (pdf) {{ENFR}} (Oct 1985)* [[Media:--File-Vortex_Ext_SPM_-_Memory_mapping_(DEU).pdf--|Memory mapping]](pdf){{DEPDF}}* [[Media:--File-Vortex_Ext_SPM_-_Principe_of_operation_and_control_%28ENG%29(ENG).pdf--|Principe Principle of operation and control]](pdf){{EN}}* [[Media:--File-Vortex_Ext_SPM_-_Principe_d%27utilisation_des_cartes_d%27extension_RAM_%28FRA%29.pdf--|Principe d'utilisation des cartes d'extension RAM]](pdf){{FRPDF}}
== Software ==
* [[Media:BOS10ALT.ZIP]] - BOS v1.0 ROM-image (Alternative version)
* [[Media:Bos21.zip]] - BOS v2.1 ROM-image
* [[Media:BOS21 664.zip]] BOS v2.1 ROM-image (CPC 664 version)
* [[media:vramid.zip|Vortex RAM ID ROM]] - RAM ID ROM Image
== Weblinks ==
* [http://www.vortex.de Vortex/ICP-Homepage]
* [http://www.cpctech.org.uk/docs/sp512.html Vortex SP512 RAM Card]
[[Category:Peripherals]] [[Category:Manual]][[Category:Memory expansions]][[Category:Expansion ROM]]