CPC X-MEMis a 512KB RAM and 512KB ROM Expansion made by [[TotO]] from [[ACME]]. Realeased on March 2014.It can be paired with a [[Y-MEM]] to expand the CPC to 1MB RAM and 1MB ROM.
== Technical ==
ROMs are selected using the normal ROM selection I/O port (DFxx).
The * If 'ROM read' is active then CPC sees 16KB will see 16 KB pages from the X-MEM flash at rom ROM slots 0-15 6 and &408-&4f31. If boot from CPC, then ROM 0 will be from CPC.
Rom slots * If 'free' is active, the CPC will also see 16 KB pages from the X-MEM flash at &40-&4f . All are always visible regardless of the ROM lock booting from CPC or ROM boot switches whereas 0X-15 depend on these switchesMEM. If you wish to program ROM select &47 contains the flash use the rom slot &40-&4f rangealternate lower ROM.
* When "boot from CPC" is activatedactive, rom 0 and OS and BASIC are from CPC and not paged in by the from X-MEM but they can still be accessed at &40 etc-&4f if free is set.
* If you wish to program the flash make sure 'free' is set and use the rom slots in the &40-&4f range. * The flash is mapped contiguously to roms 0&40-15 &4f so that when programming the flash you need to translate the flash address from the datasheet to an appropriate rom slot and address in the range &c000-&ffff.
e.g. for flash address &05555 use DF41 and address &D555. For &2aaa this is DF40 and address &EAAA.
* If 'free' is set then writes to &c000-&ffff go to both to the flash and to ram. When the upper rom is paged in, writes to &c000-&ffff go to the ram as normal.
* Writing to the flash doesn't require the upper rom to be paged in.
* If 'lockrom read' is not set, x-mem doesnroms are not visible at all and flash can't activate the rombe accessed.
== X-MEM Floppy Disc Utilities ==
This program allows to install the X-MEM after the Init pass. Also, it can up- date the Firmware and BASIC, targeting your CPC and keyboard layout. RUN”INSTALL”
The process takes few seconds for reprogramming the Lower ROM and ROM
0. Then you will be able to choose the CPC target model for programming the X-MEM. Notethat Note that ROM 1 willbeusedinthefuturetoextendthe will be used in the future to extend the Firmware 3.14. Currently, a 448K RAM Drive“C”is Drive “C” is installed. Use |C from BASIC or C: from CP/M.
=== X-MEM Rescue Pass ===
==== 3. Burning ROMs ====
There are different ways to flash a ROM:* Using Firmware 3.15: You can program the ROM from BASIC into the X-MEM: CALL &B8DD,<source>,<rom_id>
i.e. “CALL &B8DD,&4000,15” set the ROM 15 with 16K loaded at &4000.
* Using FutureOS: Use the convenient [[ROManager]] to manage all your ROMs.
=== FutureOS Lower ROM ===
A4: Try to boot with the ESC key pressed, then apply the X-MEM rescue pass.
[[Category:Memory expansions]][[Category:Expansion ROM]]
[[Category:FutureOS]]
[[Category:Peripherals]]
Website: [http://centpourcent.net centpourcent.net]