NOTE:
This module may be distributed freely without profit. If used
in any commercial way, I ask to be notified of the fact.
Permission is granted to bundle this software with systems
sold for profit.
Thou Shalt, However, Not Ask Money for DSKRAM by Itself!!!
S. Kluger
7120 Skillman #2104
Dallas TX 75231
DSKRAM is a RAM-disk emulator designed for 16 bit TurboDOS.
1. Installation
Include DSKRAM in your slave GEN file, then replace STDSLAVE
with STDSLAVX. NOTE: you may have to remove RTCMGR from
STDSLAVX.O; ask your OEM or dealer if you can't do it.
In the slave .PAR file, two equates must be added and one
must be changed. NOTE: the MEMTBL equate may not be present
in a 256k slave PAR file...
Sample PAR files (relevant parts shown only):
a. default configuration - 512k slave with 256k ram disk
MEMTBL + 3 = (0x4000-0x50) ; set upper memory limit for OS
SEGDSK = (0x4000) ; beginning segment for ram disk
NUMSGS = 4 ; 4 segments for ram disk (64k ea)
b. 256k slave with 128k ram disk:
MEMTBL + 3 = (0x2000-0x50)
SEGDSK = (0x2000)
NUMSGS = 2
c. (the max) 1MB slave with 784k ram disk
MEMTBL + 3 = (0x4000-0x50)
SEGDSK = (0x4000)
NUMSGS = 12
Got the message, right? Now, of course you have to add a
DSKAST line to your sale PAR file, carefully skipping over
drives that already exist, then change your master PAR file
to allow everyone to access the new drive. Here is a sample
assuming the slave with the ram disk is #9:
Slave:
DSKAST = 0x80,(0),0x81,(0),0x82,(0),0,DSKDRA ; A,B,C on master,
; ram disk is D:
Master:
DSKAST = 0,DSKDRA,1,DSKDRA,0,DSKDRB,83,(9) ; A,B,C local,
; D drive 4 on slv 9
2. Operation
The ram disk driver is a bit intelligent in that once it is
loaded and the drive has been set up, it will not reformat
the drive after a slave reset unless the directory label
entry is munched.
When bringing up the ram drive, simply ERASEDIR it. It is
important that you make the directory HASHED, else the driver
will erase the whole "disk" after a slave reset!
The drive is set up to have 256 byte physical sectors with 4
sectors per "track" and 256 directory entries. It has as
many "tracks" as there are k bytes assigned to it.
3. Bugs
DSKRAM was a 2-hour creation, thanks to the simplicity of
TurboDOS' disk driver requirements. It has been tested
and will continue to be tested. if you turn up any bugs,
please let me know at the address above.
