To: 999 (all members) From: K5B (David J.MacGraw.) Subject: 512 and DOS+ (Part 4) Copying COMMAND.COM to a ramdisc (M:) and amending the COMSPEC environment and PATH variables accordingly greatly speeds re-loading when necessary and ends Unable to load COMMAND.COM errors.The COMMAND/C <program name> construct for those programs requiring a second COMMAND.COM becomes almost transparent.Similarly, the COMMAND <2nd.batch file>substitute for DOS3.3's CALL 'sub-batchroutine' command is equally effective. Many DOS programs permit 'shelling-out'whereby the current application is leftin abeyance and control returned to theuser usually by re-loading COMMAND.COM.Again, using a ramdisc copy makes this process virtually immediate. Return to the original program is normally done by entering the EXIT command. TIP: Try Ctrl/C or Ctrl/Break instead of typing EXIT. Many programs (eg. LISTv7.6b, QEdit v2.1, FED v1.51) respond correctly to this. NB: DOS's Ctrl/Breakmeans Ctrl and the numeric keypad Breakkey (ie. the 'hash' symbol below '*'), NOT the Beeb's hard break combination! One minor annoyance when 'shelling-out'is the over-writing of the Type EXIT toreturn to ----- line by DR's copyright message. One solution is to edit the string to include a CR+LF at the start.Using a hex file editor ON A COPY FIRSTamend the bytes at offset 0654E onwardsfrom "DOS Plus" to 0D,0A,"DRDOS+".
Another tweak to COMMAND.COM (06.01.87)which may be of use is to change the byte at offset 0168F from 07C to 07F. This permits the '|' character to be used in, for example, batch files. One need for this is to prepare the Beeb's soft keys for use when using STAR or ES's OSCLI/SuprStar commands to includecontrol characters. The ramdisc is also useful for keeping oft' used utilities. One which I use a lot is Colour.EXE. This presets my CGA palette correctly for doing PCB layoutsetc. and needs to be called four times before and after running the program, along-winded task even with a hard disc!A 're-entrant' batch file (called AUTO so I can just press f1 - see Pt.3) doesall the preparation needed, as follows:
echo off suppresses some screen output
cls clears the screen
if %1 == RAM goto INM re-entrant call?
if exist m:auto.bat goto RAM 1st call?
mouse install 512 mouse driver
ps3 install Problem Solver
MemoPad 5 install ES MemoPad
PadLoad load specific pad data
copy ½system½colour.exe m: copy utility
copy auto.bat m: copy self
m:auto RAM repeat from ramdisc
thin change font
colour 0 6 change colour palette
colour 1 4
colour 5 1
colour 6 4
c: return to PCB directory
EasyPC run PCB program session
m: return to ramdisc
colour 6 1 restore colour palette
colour 5 6
colour 1 7
colour 0 0
normal restore font
c: return to PCB directory Having installed the required programs the file recalls itself from ramdisc toexecute the 4 colour changes needed; after the session it then restores the palette, again at lightening speed! Next time, ES's 'essential' collection of utilities and their hotkeys.