Difference between revisions of "CP/M 3.0"

Revision as of 07:54, 24 April 2018

CP/M 3.0 after boot

Amstrad CP/M+ uses Amstrad's "System" format. This is 40 tracks, 1 side, 9 sectors per track numbered &41-&49. There are two reserved tracks, then the directory which has 64 entries, and then the data area.

CP/M is booted using an RSX command "|CPM" which is implemented in the Amstrad disc rom (AMSDOS).
|CPM loads track 0, side 0, sector &41 into RAM at &100-&2ff. This is the boot sector and contains the boot program.
The boot program then loads the directory from track 2, sector &41.
The boot program locates a program with extension "EMS".
This program is loaded into RAM at &c00.
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.)

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 [[Image:cpm30boot.jpg|thumb|300px|CP/M 3.0 after boot]]
+== Amstrad's CP/M+ ==
+* Amstrad CP/M+ uses Amstrad's "System" format. This is 40 tracks, 1 side, 9 sectors per track numbered &41-&49. There are two reserved tracks, then the directory which has 64 entries, and then the data area.
+* CP/M is booted using an RSX command "|CPM" which is implemented in the Amstrad disc rom (AMSDOS).
+* |CPM loads track 0, side 0, sector &41 into RAM at &100-&2ff. This is the boot sector and contains the boot program.
+* The boot program then loads the directory from track 2, sector &41.
+* The boot program locates a program with extension "EMS".
+* This program is loaded into RAM at &c00.
+* 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.)
 [[Category:CP/M]][[Category:Operating System]]