-=> Quoting Denis Boyles to Kevin Barrow <=-
 DB> @MSGID: 1:153/290.0 32f939f6
 KB> DB> TSR's PSP making DOS use that instead. Next the TSR's MCB is 
`altered'
 KB> DB> to reflect the size of memory being used. This was determined by the
 KB> DB> `dummy' allocation call used at init.
 
 KB>MCB? I know About the PSP and ENV but what is the MCB? and just how
 DB> The (M)emory (C)ontrol (B)lock is a 16 byte data structure that DOS
 DB> uses to control memory allocation. DOS uses the MCBs to keep track of
 DB> the memory segments. This allows DOS to check available memory,
 DB> allocate it, free it, etc. While the MCB is 16 bytes in size, only the
 DB> first 5 bytes are actually used.
Half correct:
Format of memory control block:
Offset  Size    Description
 00h    BYTE    block type: 5Ah if last block in chain, otherwise 4Dh
 01h    WORD    PSP segment of owner, 0000h if free, 0008h if belongs to
                DOS
 03h    WORD    size of memory block in paragraphs
 05h  3 BYTEs   unused
 ---DOS 2.x,3.x---
 08h  8 BYTEs   unused
 ---DOS 4.x---
 08h  8 BYTEs   ASCII program name if PSP memory block, else garbage
                null-terminated if less than 8 characters
Peter
... Situation Normal. Please Panic Accordingly.
--- GEcho 1.11+
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