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From: wfp@dasys1.UUCP (William Phillips)
Newsgroups: comp.sources.wanted,comp.binaries.ibm.pc.d,comp.sys.ibm.pc
Subject: Re: Software turbo switch for PC clone
Summary: Here's one
Keywords: turbo, PC clone
Message-ID: <6782@dasys1.UUCP>
Date: 2 Oct 88 23:57:13 GMT
References: <5009@medusa.cs.purdue.edu>
Reply-To: wfp@dasys1.UUCP (William Phillips)
Organization: Big Apple Home for the Thoroughly Confused
Lines: 40

In article <5009@medusa.cs.purdue.edu> goehring@cs.purdue.EDU (Scott Goehring) writes:
>Looking for a program that will kick a clone into 8MHz mode automatically
>(without having to use the keyboard).  For autoexec files.

Funny.  I just wrote one the other day.  I can't guarantee that it'll
work on _your_ machine, but it might.  I just explored the BIOS (int 09h) until
I found the code executed when ctrl-alt-grey_minus is detected, and
changed a few lines to give me an underscore cursor instead of the ugly
blob the BIOS makes.  You can change it as you like by changing
0B0C (cursor lines 11-12) to whatever you prefer; 0607 is standard for a CGA,
for example.

It's a DEBUG script:

------------------------------------------------------------------------------
N TURBOXT.COM
A
IN	AL,61                              ; get 8255 port B
OR	AL,04                              ; set unused (turbo) bit
OUT	61,AL                              ; and output
MOV	AH,01                              ; set cursor type function
MOV	CX,0B0C                            ; 11 12 for mono/herc (6 7 for cga)
INT	10                                 ; video interrupt
INT	20                                 ; and terminate
 
RCX
0F
W
Q
------------------------------------------------------------------------------

I put this into my AUTOEXEC.BAT, and now my system comes up in turbo (8 Mhz)
mode.

Hope it works for you!

-- 
William Phillips                 {allegra,philabs,cmcl2}!phri\
BEC Public Excess Unix           {bellcore,cmcl2}!cucard!dasys1!wfp
New York, NY, USA                !!! JUST SAY "NO" TO OS/2 !!!