Re: C= parts: Amiga ROMs

From: Marcello Magnifico (
Date: 2000-12-07 20:30:32

> > ROM with Kickstart 2.04 is both A500+ and A3000. Kickstart
> > 2.05 came out on A600 and was only used on that one.

> In fact, I've got an A600 with the 2.05 kickstart.
> But I've also seen some A500+ with the old 1.3 kickstart...

Hi, Dan.
The A500+ you saw must have been modified by its owner. AmigaOS 1.3 and
lower simply don't handle (=doesn't know about) ECS video modes. Usually
this mod was installed with a tiny board and a switch, to select one
between two Kickstart ROMs. I have seen an A600 modified that way
(2.05/1.3), and an old A500 (1.3/1.2). It was mainly done to run older
games, written in spite of Commodore's recommendations about library
function calls (direct jump into ROM code instead of looking up ExecBase 
and branching). Many projects exist about that, including one that allowed
usage of _three_ (yeah!) different chips.
Something strange is puzzling me, anyway: why are there on the list two
ROM chips for the 2.04? Might one of the two belong to late CDTV machines?
I heard of some (very few) 2.0x CDTVs that were built before that machine
was dropped.

Let's go on.
A1000 ROMs should be really small, because they just contain a loader
to read a 256K Kickstart from "DF0:". All ROM chips after those and before
3.0 should be 512K. 3.0 and later are 1MB. Since "official" Kickstart
size upto and including 1.3 should be no more than 256K (to enable usage
on the A1000), the rest is where all extra routines on the 1.3 CDTV (CD
controller handling, ISO9660 f/s) were placed. A500 is either 1.2 or 1.3.
A500+ is 2.04. Some early A3000 are 1.3 (Commodore softkicked them when
2.0 wasn't 2.04 yet). A2000/A (Braunschweig project?) should be mainly 1.2
unless modified. A2000/B (Los Gatos project?) are 1.2 and (more likely)
1.3. A2000/C (Los Gatos? w/ECS) are 2.04 or 2.05 (don't know; 2.05 would
run but there's no need of it because it was designed for A600's IDE and
PCMCIA). Plain 2.0 should be A3000 only, unless another error or ignorance
on my side.
Don't know anything on the A1500, because it wasn't ever sold in Italy:
does someone have a tech dossier on his/her personal Web pages, possibly
with an image?


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