== Amstrad's implementation of CP/M+ ==
Amstrad distributed CP/M+ on the side 4 of the system discs that came with the CPC6128. It requires a Dk'Tronics compatible ram expansion. It provided 61K TPA. CPM+ doesn't use the firmware. To get 61K TPA, CPM+ uses 'C1' and 'C2' RAM configuration with most of the code TPA in the 2nd bank of 64KB leaving almost all and the CCP, BDOS, BIOS, screen and firmware in the 1st bank of 64KB of RAM. This arrangement allows 61KB useable for programs.
On side 1 of the system discs was CP/M 2.2.
* This is then executed. (EMS contains the BIOS, BDOS and relocates and re-configures the memory. CP/M doesn't use the CP/M 2.2 BIOS from the Amstrad disc ROM.)
=== Memory layout ===
* 1st 64KB has the CCP, BDOS, BIOS, screen and firmware. Screen is at &4000-&7fff. Firmware is used. AMSDOS is not used.* There is some trampoline code at &c000-&ffff. C1 configuration is used. (this has C7 at &c000-&ffff)* 2nd 64KB has the TPA and complementary trampoline code. c2 configuration is used.a) Page C4 has WBOOT and BDOS jump + &100-&3f00 of the TPA. This calls to functions in Page c7.b) Page C5 has &4000-&7fff of the TPA.c) Page C6 has &8000-&bfff of the TPA.d) Page C7 has &c000-&f2fb of the TPA. From &f2fc to &ffff is the trampoline code which transitions * to 1st bank of 64KB.
[[Category:CP/M]][[Category:Operating System]]