DkTronics CPM - Revision history

Arnoldemu: /* CPM2.2 with Memory Expansions */

2019-12-08T11:47:46Z

‎CPM2.2 with Memory Expansions

JohnElliott at 09:51, 5 April 2019

2019-04-05T09:51:49Z

JohnElliott: Formatting

2019-04-05T09:51:07Z

Formatting

JohnElliott: /* CPM+ with Memory expansions */

2019-03-06T11:42:04Z

‎CPM+ with Memory expansions

JohnElliott: /* CPM+ with Silicon Disk */

2019-03-06T11:38:13Z

‎CPM+ with Silicon Disk

Arnoldemu: /* CPM 2.2 with Silicon Disk */

2019-02-16T18:18:26Z

‎CPM 2.2 with Silicon Disk

Arnoldemu: /* Downloads */

2019-02-16T18:16:38Z

‎Downloads

Arnoldemu: /* CPM2.2 */

2019-02-16T18:14:50Z

‎CPM2.2

Arnoldemu: /* CPM+ */

2019-02-16T18:14:32Z

‎CPM+

Arnoldemu at 13:50, 15 February 2019

2019-02-15T13:50:48Z

← Older revision		Revision as of 11:47, 8 December 2019
Line 98:		Line 98:

	Dk'tronics Bank Switch software comes with NEWCPM.COM CP/M program which installs a 61K TPA CPM2.2 which uses the Dk'Tronics RAM. The documents describe how to make this CPM. They are repeated here and a pre-made dsk is linked to this page.		Dk'tronics Bank Switch software comes with NEWCPM.COM CP/M program which installs a 61K TPA CPM2.2 which uses the Dk'Tronics RAM. The documents describe how to make this CPM. They are repeated here and a pre-made dsk is linked to this page.
		+
		+	===ENTER FIRMWARE===
		+
		+	Dk'tronics NEWCPM.COM doesn't support using ENTER FIRMWARE from TPA because it runs from bank 2 of memory.

	===Creating the DkTronics 61K TPA CPM 2.2===		===Creating the DkTronics 61K TPA CPM 2.2===

@@ Line 86: / Line 86: @@
    RET		;success
-) and FLUSH (a simple RET).
+) and INIT (a simple RET).
 ====Banked BIOS====

@@ Line 75: / Line 75: @@
 After initialisation, the next two patches are helper functions, which occupy free space between CP/M modules. One is at 03E9h, in the gap between the CD and TE modules; the other at 0EE2h, in the gap at the end of DD. The first one backs up 128 bytes of memory at 8080h (which is normally used by the font) so it becomes available as a transfer buffer. The second reverses this, restoring the font.
-Disk access
+====Disk access====
 The disk access functions follow; these are placed between 8960h and 89FFh, in memory that's probably reserved for the system message table. Since they page memory, they switch to a local stack, which grows down from 3CFEh.

@@ Line 16: / Line 16: @@
 The other version doesn't require BANK. You only need to type:
   |CPM
 == CPM+ with Silicon Disk ==

← Older revision		Revision as of 11:38, 6 March 2019
Line 20:		Line 20:

	The Silicon Disk rom has a command "\|SETCPMPLUS" which patches the Amstrad CP/M with support for the Silicon disk. The resulting EMS file is called CPM3SEMI.EMS.		The Silicon Disk rom has a command "\|SETCPMPLUS" which patches the Amstrad CP/M with support for the Silicon disk. The resulting EMS file is called CPM3SEMI.EMS.
		+
		+	===Technical===
		+
		+	The \|SETCPMPLUS command creates a file called PATCHER.COM, which contains (at offset 689h) a table of changes to make. The changes are made blindly to the first EMS file that PATCHER.COM finds; the user is responsible for ensuring it is run on a genuine C10CPM3.EMS.
		+
		+	Each change is formed:
		+
		+	DW start ;Address of first byte to change
		+	DW end ;Address of last byte to change
		+	DB data ;Replacement bytes
		+
		+	The addresses are as if the EMS file was loaded at 0100h.
		+	====Initialisation====
		+
		+	The first few changes are to the initialisation code at the start of the EMS file:
		+
		+	DW 107h ;Replace a call to 0BD19h (MC_WAIT_FLYBACK) with a
		+	DW 108h ;call to initialise the ramdisc.
		+	DW 7100h
		+
		+	DW 1C5h ;Remove the LDIR that clears memory between
		+	DW 1C6h ;0FE58h and 0FF9Fh (this has been populated by the.
		+	DW 0 ;initialisation call).
		+
		+	DW 1D5h ;Place a RET at the start of the firmware version
		+	DW 1D5h ;check, so that CP/M will run on a 464/664.
		+	DB 0C9h
		+
		+	DW 358h ;Display the Silicon Disk sign-on message.
		+	DW 359h
		+	DW 0FE80h
		+
		+	The first change sets up the call to the code that initialises the ramdisc. This code consists of 512 bytes added to the end of the EMS file; since it is not trying to fit in spare space within the existing CP/M system, it is not as constrained for memory as the other patches.
		+
		+	The initialisation code copies itself to 0100h, and runs from there. The first thing it does is probe for available memory. There are two possible memory ranges: 192k (banks CC-CF, D4-D7, DC-DF) and 256k (banks E4-E7, EC-EF, F4-F7, FC-FF). The ramdisc can occupy either or both. If neither range is available, no drive is added to the system, and a minimal version of the sign-on routine (which displays no message) is constructed at 0FE80h.
		+
		+	Assuming that memory was found, the DPH for the new drive is added to the drive table. The first memory bank of the ramdisc is paged in, and the system checks that the first byte of each directory entry is either 0E5h or 00h-0Fh. If it is not, the entire first bank is cleared to 0E5h. This means that the presence of CP/M disc labels or date stamps will cause the ramdisc to be erased on boot.
		+
		+	The appropriate DPB for the size of ramdisc is copied to 0FF53h and the sign-on message altered to hold the correct size. The full version of the sign-on code is copied to 0FE80h.
		+
		+	Finally memory from 0FF64h to 0FF9Fh is blanked and the code resumes the normal initialisation sequence by jumping to MC_WAIT_FLYBACK.
		+	====Helper functions====
		+
		+	After initialisation, the next two patches are helper functions, which occupy free space between CP/M modules. One is at 03E9h, in the gap between the CD and TE modules; the other at 0EE2h, in the gap at the end of DD. The first one backs up 128 bytes of memory at 8080h (which is normally used by the font) so it becomes available as a transfer buffer. The second reverses this, restoring the font.
		+	Disk access
		+
		+	The disk access functions follow; these are placed between 8960h and 89FFh, in memory that's probably reserved for the system message table. Since they page memory, they switch to a local stack, which grows down from 3CFEh.
		+
		+	The actual I/O functions are reasonably simple. READ pages in the correct bank, copies 128 bytes to the transfer buffer at 8080h, and then uses the CP/M XMOVE and MOVE functions to copy the data to the right place. WRITE performs similar operations in reverse order; XMOVE and MOVE to get the data to 8080h, then page in the correct bank and copy the data there.
		+
		+	The other two operations are LOGIN (which consists simply of
		+
		+	EX DE, HL ;DPH is passed in DE, should be returned in HL on
		+	RET ;success
		+
		+	) and FLUSH (a simple RET).
		+	====Banked BIOS====
		+
		+	The next few changes allocate space for the extra DPB. In a stock CPC CP/M Plus, the stack grows down from 0FF64h. In CPM3SEMI this is lowered to 0FF53h, freeing up 17 bytes for the drive DPB.
		+
		+	Space also needs to be allocated for the DPH. The existing subroutine at 3FE0h is moved to 3FD0h (removing 16 apparently unused bytes) and then the new DPH occupies 3FD7h - 3FF9h.
		+
		+	The new drive also requires space for an allocation vector. This is placed at 3C89h, in memory intended for patches to the BDOS.

	== CPM2.2 with Memory Expansions ==		== CPM2.2 with Memory Expansions ==

@@ Line 95: / Line 95: @@
 * OLDCPM.COM is much simpler than NEWCPM.COM. It restores the dormant CPM in bank 0. If NEWCPM.COM was used it remains dormant in bank 1.
-=== CPM 2.2 with Silicon Disk ===
+== CPM 2.2 with Silicon Disk ==
 The Silicon Disk has a command "|SETCPM" which patches CPM2.2 for the Silicon Disk.

@@ Line 94: / Line 94: @@
 * OLDCPM.COM is much simpler than NEWCPM.COM. It restores the dormant CPM in bank 0. If NEWCPM.COM was used it remains dormant in bank 1.
 == Downloads ==
-* [[File:Dkcpm.dsk]] - CPM2.2 configured for 61K TPA
+* [[File:Dkcpm.dsk]] - CPM2.2 configured for 61K TPA - This was made following instructions in the Bank software
-* [[File:Dkplusbank.dsk]] - CPM3.0 with Dk'tronics PATCH (run BANK first)
+* [[File:Dkplusbank.dsk]] - CPM3.0 with Dk'tronics PATCH (run BANK first) - This was made following instructions
-* [[File:Dkplusnobank.dsk]] - CPM3.0 with Dk'tronics PATCH (BANK not required)
+* [[File:Dkplusnobank.dsk]] - CPM3.0 with Dk'tronics PATCH (BANK not required) - This was made following instructions
 [[Category:Operating System]][[Category:CP/M]]

@@ Line 21: / Line 21: @@
 The Silicon Disk rom has a command "|SETCPMPLUS" which patches the Amstrad CP/M with support for the Silicon disk. The resulting EMS file is called CPM3SEMI.EMS.
-== CPM2.2 ==
+== CPM2.2 with Memory Expansions ==
 Dk'tronics Bank Switch software comes with NEWCPM.COM CP/M program which installs a 61K TPA CPM2.2 which uses the Dk'Tronics RAM. The documents describe how to make this CPM. They are repeated here and a pre-made dsk is linked to this page.

← Older revision		Revision as of 18:14, 16 February 2019
Line 1:		Line 1:
−	== CPM+ ==	+	== CPM+ with Memory expansions ==

	CP/M+ already supports the Dk'Tronics RAM expansion but the CP/M+ on the system discs doesn't run on the CPC464/664 because it uses firmware v1.1 calls. Dk'Tronics provide patches to allow it to run on the 464/664.		CP/M+ already supports the Dk'Tronics RAM expansion but the CP/M+ on the system discs doesn't run on the CPC464/664 because it uses firmware v1.1 calls. Dk'Tronics provide patches to allow it to run on the 464/664.

← Older revision		Revision as of 13:50, 15 February 2019
Line 17:		Line 17:
	\|CPM		\|CPM

		+	== CPM+ with Silicon Disk ==

		+	The Silicon Disk rom has a command "\|SETCPMPLUS" which patches the Amstrad CP/M with support for the Silicon disk. The resulting EMS file is called CPM3SEMI.EMS.

	== CPM2.2 ==		== CPM2.2 ==