[comp.sys.amiga.hardware] What does DeciGEL do??

hounsell@nmerh4.BNR.CA (Rob Hounsell) (02/25/91)

Folks,

  Does anyone know exactly what the DeciGEL program that comes with the LUCAS
board disks does?? It says it fixes a privilege problem. I'm assuming that this
is the instruction that is user mode on the 68000 but supervisor mode on
the '020 (which instruction???). However, after running DeciGEL, I still get
"illegal instruction/privilege" violation Gurus with some of my old software.

?????

Rob

thad@public.BTR.COM (Thaddeus P. Floryan) (02/26/91)

In article <4053@bnr-rsc.UUCP> uunet!chekov!hounsell writes:
>Folks,
>
>  Does anyone know exactly what the DeciGEL program that comes with the LUCAS
>board disks does?? It says it fixes a privilege problem. I'm assuming that this
>is the instruction that is user mode on the 68000 but supervisor mode on
>the '020 (which instruction???). However, after running DeciGEL, I still get
>"illegal instruction/privilege" violation Gurus with some of my old software.

Take a look on "Fisk Disk 18" in the MC68010 directory and you'll find a
long article I wrote about DeciGEL along with the program source and its
(original) executable.

In case it's not obvious, the very name "DeciGEL" is a pun on the "DiGEL"
antacid remedy (re: frustrations with one's computer).  The "Deci" part
and the name of the directory (MC68010) should provide a clue the fix is
for 68010 CPUs.  By the time I put a 68020 in the Amiga around early 1986,
I stopped buying/using software that "broke the rules" and thus haven't
needed DeciGEL.

Back then I and others were publically blasting EA and others on The WELL,
FAUG BBS, BBS-JC, BBS-HT, Amiga/OZ, and the Amiga Developers' Exchange for
their controversion of Amiga programming guidelines which were first issed
(in print) during the May 1985 DevCON.  Some of the problems were due to
early versions of the Lattice 3.0* libraries (re: MOVE SR,..) and others
were due to stupid programming practices used in copy protection;
yes, the copy protection flames have accompanied the Amiga almost since
day 1.

DO NOTE there's an updated version in the recent batch of Fish Disks (btw.
451 and 460) specifically for the '020 and '030 CPUs; the updated version
is from Bryce (at CBM) if I recall today's posting in comp.sys.amiga.announce
correctly.  Too bad the name wasn't changed to ScoreGEL or sumtin'  :-)

Thad Floryan [ thad@btr.com (OR) {decwrl, mips, fernwood}!btr!thad ]