Difference between revisions of "CP/M 3.0"

Revision as of 07:51, 27 April 2018

CP/M 3.0 after boot

Amstrad distributed CP/M+ on the side 4 of the system discs that came with the CPC6128. On side 1 was CP/M 2.2.

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.)

@@ Line 1: / Line 1: @@
 [[Image:cpm30boot.jpg|thumb|300px|CP/M 3.0 after boot]]
-== Amstrad's CP/M+ ==
+== Amstrad's implementation of 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.
+Amstrad distributed CP/M+ on the side 4 of the system discs that came with the CPC6128.
+On side 1 was CP/M 2.2.
+* 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.