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1991-11-29
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94 lines
A3000 Kickstart ROM Procedure
This document describes how to create your own 2.04 (or later)
ROM-based A3000. It entails procedures & modifications that you may need
to make to your A3000. It requires the A3000 superkickstart disk and
two 200 nanosecond or faster 27C220 EPROMS. For obvious copyright reasons,
I cannot distribute the actual kickstart ROM images, but the program
ROMSPLIT or ROMSPLIT1 will create the images from your A3000 which
most eprom programmers can read.
The next question is why create EPROMS? Well, 68040 cards for the A3000
require 2.0 in ROM. These cards are ready and shipping but A3000s
with 2.0 in ROM aren't shipping yet. With this procedure you can make
copies for yourself in a legal manner. Developers can use their
040 machines to test newer betas (beyond 2.04) without having to pull
out their 040 cards. The reason the superkickstart process fails on
040 cards is that the kickstart ROM image is remapped into fast ram
via the MMU. The 040 MMU is different enough from the 030 MMU that
the bootroms crash.
The programs ROMSPLIT and ROMSPLIT1 are hereby released to the public
domain with no distribution restrictions whatsoever.
WARNING! Performing these procedures will probably take your A3000 out
of warranty. Please carefully read the instructions completely and
do not start until you thoroughly understand the process.
1) A3000s have four ROM sockets. Only two are used in any one machine. Most
A3000s have special bootroms which load kickstart 2.0 and 1.3 from
disk. These ROMs must be pulled. Earlier A3000s used 27C220s, later
ones use masked ROMs, with each tpe using a different pair of sockets on the
A3000 motherboard. The four ROM sockets are located on the motherboard
along the right-hand side of the A3000. The first (front) two are for the
Masked ROMs,the second two are for EPROMS.
2) Unfortunately CBM started to not solder the EPROM sockets into the
most current A3000s although the traces and holes are there. To use these
machines, you must unsolder the holes, put in a 40 pin socket and perform
a decent soldering job. To effectively desolder the motherboard holes for
EPROM sockets, you must remove the motherboard. A temperature controlled
grounded tip desoldering station is strongly suggested. In soldering on your
A3000 motherboard, you will definitely void warranty and you perform this
procedure ENTIRELY AT YOUR OWN RISK!
3) By running the Update2.x program on your A3000 install disk, put the
kickstart image for the version of the ROM which you want onto your
disk. It will be called kickstart and located into your devs: directory.
4) Depending on your EPROM programmer, run ROMSPLIT or ROMSPLIT1. These
programs read the devs:kickstart file and create two binary output files
called Kickrom0 and Kickrom1. ROMSPLIT stores the image in order as read
by the 68030 processor. ROMSPLIT1 performs byte shuffling required by the
Intel processors. My BP Microsystems EP-1140 programmer requires that
ROMSPLIT1 be used. I suspect that most programmers will want Intel
byte ordering, but I included both programs just in case.
5) Copy Kickrom0 and Kickrom1 files to your EPROM programmer. Use
CrossDos, or Lharc the files and use a telecom program, use whatever works.
On the EP-1140, I use CrossDos and a 720K formatted diskette to put the
files on my 386PC. I then load the programmer software, select
INTEL 27C220 and load binary file. Note that some programmers may not
load binary files. Most do.
6) Program the EPROMS.
7) Take the EPROMS and put them into the last two ROM sockets (The furthest
two ROM sockets from the front of the A3000. Note that Kickrom0 corresponds
to ROM0 and Kickrom1 corresponds to ROM1. If your A3000 had EPROMS, read
the label. It usually identifies which ROM goes where. If not, look at the
silkscreen. It identifies ROM0 and ROM1. Be careful of PIN 1 orientation!
Make sure all pins go into the sockets.
8) Make sure that if your A3000 has masked ROMs that you pull them out of
their sockets; there should only be two ROMs or EPROMs in the machine at a
time.
9) Put the A3000 back together. Power up. Note that the A3000 daughtercard
must be installed for the system to work. If the machine doesn't come up,
recheck ROM installation. Try swapping the two ROMs (The silkscreen may
be wrong on Rev 7 motherboards). In worst case, put the original bootroms
back in and see if you can boot. Perhaps you can reprogram using the
opposite program (ROMSPLIT versus ROMSPLIT1), which generates different
EPROM binary files.
10) At this point, the machine is running 2.0 in ROM.( You could possibly
do 1.3 as well!!) This procedure has been tested with 37.175 and newer
beta versions and found to work in these cases.
11) For more performance, you can obtain faster 27C220 EPROMS. 150 nsec
speed Eproms will allow you to play with jumpers (see your A3000 manual)
to cut out a few wait states. Generally, put the ROM speed jumpers in the
16 Mhz position.