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This article was posted to the Usenet group alt.hackers in 1995; any technical information is probably outdated.

Re: Another first post.


Article: 7469 of alt.hackers
From: djimenez@rose.uthscsa.edu (Daniel Angel Jimenez)
Newsgroups: alt.hackers
Subject: Re: Another first post.
Date: 2 Mar 1995 14:25:15 -0600
Organization: University of Texas Health Science Center at San Antonio
Lines: 25
Approved: djimenez@rose.uthscsa.edu
Message-ID: 3j59jb$dtk@rose.uthscsa.edu
NNTP-Posting-Host: rose.uthscsa.edu
Status: RO

In article <1009akdf9q6@somewhere.org>,  <someone@somewhere.org>
wrote:
>ObHack:
>
>The old Color Computers (Coco's) could not display lower case, instead it
>used inverse video to symbolize lower case characters. A new revision of
>the Coco's had a Video Display Generator that could support lowercase, but
>this feature was not used to maintain backwards compatibilty with the
>older models. Using a 74157 TTL quad data selector and my Tandy service
>manual I was able to force the VDG in to true lowercase while keeping with
>backwards compatibilty.

Hmm, I did this all in software.  As I recall, I set (or maybe cleared)
some bit in the VDG area, then NOPed out the code around $A282 that
reset that bit everytime a character is printed.  Worked nicely.

ObCoCoHack:
I wrote some patches that let you use the double sided diskettes
as two different disks or as one "big", i.e., 360K disk.
The hack part
was using the `DOS' command to load the patches into Disk Extended Color
BASIC.  Any disk formatted by my special software had the patches put into
the area DECB loaded with `DOS', kind of like a virus :-)
--
Daniel Jimenez                     djimenez@rose.uthscsa.edu
"I've so much music in my head" -- Maurice Ravel, shortly before
his death.
"                             " -- John Cage



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