RAMDSKRB.DOC

	INTRODUCTION

	RAMDSKRB.CMD is an enhanced version of MDRIVE.CMD, which is 
	included as a utility program in DIGITAL EQUIPMENT CORPORATION's
	releases of CP/M-86/80 V2.05 and V2.10.  To minimize possible
	confusion and insure consistancy with DEC's manual, it is 
	suggested that RAMDSKRB.CMD be renamed MDRIVE.CMD.

	This enhancement extends MDRIVE from a maximum of 8) 64K blocks to
	12) 64K blocks on Rainbow 100B's with 896K of ram or 11) 64K blocks
	on Rainbow 100A's with 832K of ram.

	GENERAL INFORMATION

	RAMDSKRB.CMD was created directly from MDRIVE.CMD using DDT86 with
	out the benefit of source code, hence, source code for RAMDSKRB.CMD
	is not available.  Prior to this modification, I had no experience
	in assembly language programming with any microprocessor.  My only
	references were the DIGITAL RESEARCH CP/M-86 "System Guide" and
	"Programmers Guide".  I, therefore, believe that those who feel
	the need to have source code listings are sufficiently knowledgeable
	to disassemble RAMDSKRB.CMD using DDT86.

	Any comments, suggestions, complaints and especially pats on the
	back are welcome.  Questions should be sent to me with a self-
	addressed stamped envelope.

				Joseph C. Gugel, Jr.
				159 High St.
				Nutley, N.J.  07110

	or a message may be left, to my attention, on the NY-ACC BBS at
	718-539-3338.

	TECHNICAL

	RAMDSKRB is Rainbow specific and will run only on CP/M-86/80
	version 2.05 or later.  The operation of RAMDSKRB is functionally
	identical to DEC's MDRIVE except as previously noted.

	The minimum memory required to run RAMDSKRB is 192K and the maximum
	available is 128K less than the total memory, 700K and 764K in fully
	loaded 100A's and 100B's respectively.  Below 192K, (3 blocks)
	RAMDSKRB requires 2K for the directory and above 192K, (4 blocks)
	the directory requires 4K.














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				RAMDSKRB.DOC cont.


	Following, is a listing of the major patch areas as viewed from DDT86:

	     MDRIVE    |  RAMDSKRB   |           EXPLANATION
	_______________|_____________|_______________________________________
		       |	     |
	1. 650:197-1AB | 650:197-1B1 |  Modified to accept 2 valid characters
		       |	     |	(0 - 12) from the command line.
		       |	     |
	2. 650:1D1-1DD | 650:1D9-1E7 |	Modified to allowed the program to
		       |	     |	prompt more than 8) 64K blocks
		       |	     |	memory permitting.
		       |	     |
	3. 650:207-225 | 650:215-247 |	Modified to accept 2 valid characters
		       |	     |	(0 - 12) from program prompting.
		       |	     |
	4. 650:229-23C | 650:248-26A |	Modified to configure the File Control
		       |	     |	Block Extent (40:3FB4) to allow more
		       |	     |	than 512K.
		       |	     |
	5. 650:5AD-5BD | 650:5D9-5E8 |	Modifies the message section to report
		       |	     |	the 4 new blocks "disk" area.






































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