Memory

My problems with my hard drive, unfortunately weren't my first problems 
when upgrading an Atari. The year before my Grandfather decided to upgrade 
the memory in his 520STFM to 1Mb. However, he didn't want to fit the 
upgrade himself, so he asked me to fit it for him. He had ordered an 
Xtra-Ram Deluxe board on my advice, as these boards were well-praised in 
magazines like Atari ST Review at the time. As I was away when it arrived 
in late July, he had a look at the instructions and decided that he wasn't 
going to attempt fitting it himself, and waited for me to return.
When I returned, I read the instructions that came with the upgrade before 
attempting to proceed with the installation. The first problems began 
before I'd even finished stripping the machine down. The instructions for 
the upgrade said that to remove the shielding from around the motherboard 
(the main part of the computer) you had to remove the power supply, and 
then remove the top shielding, however on this machine (and both of my own 
machines) the power supply is screwed into the bottom piece of shielding, 
so can't be removed. The top piece of shielding can't be taken out as the 
reset button and power switch pass through holes in the back of the 
shielding.
A quick phone call to Marpet sorted this problem out, on machines like 
this the whole of the shielding and motherboard must be removed from the 
case and then the top piece of shielding can be removed. Once the 
shielding is removed you need to locate the MMU chip, which is responsible 
for making sure the right piece of memory is accessed and the SHIFTER chip 
which handles the graphics. The memory upgrade board plugs in over these 
chips, and this is where the second problem lay.
The connection to the SHIFTER chip is made by unplugging the chip from its 
socket, plugging a small circuit board into the socket and then plugging 
the chip into the new socket on the circuit board. This part proceeded 
without any problems, great care was taken when removing the chip to make 
sure none of the pins were bent during the process.
Problems began when I tried to fit the adapter onto the MMU chip. The MMU 
chip comes in many forms, square, or the rare rectangular one, sometimes 
they are connected straight onto the motherboard and sometimes they are in 
sockets. The upgrade supplied an MMU adapter for a square, socketed chip, 
but the ST had a chip that was connected straight to the motherboard. My 
Grandfather sent the adaptor back to Marpet, with a note asking for the 
correct sort. Unfortunately, I wasn't around to fit this when it arrived 
so he took it to a friend who repaired video machines, and asked him to 
fit it.
When the machine returned it wouldn't work, when he switched it on all 
that happened was a white screen appeared. He rang me up and asked what 
was happening, so I shot 50 miles down various motorways to Coventry, to 
have a look. Upon looking inside the machine, I immediately saw the 
problem, the MMU adapter had been placed over the wrong chip, so I 
switched it over hoping this would solve the problem. Unfortunately, it 
didn't there was still only 512Kb memory in the machine. As I couldn't 
stay for very long, I left the machine working as a 512Kb machine and 
arranged to fit the upgrade when I was coming to stay a couple of weeks 
later.
When I tried again to fit the upgrade, I still didn't have any luck, but 
it was the most interesting upgrade I've ever performed. As I had 
dismantled his computer setup, my grandparents decided to rearrange the 
furniture, this meant that I would place part of the computer on the table 
next to me and when I went to pick it up again it was on the other side of 
the room! These were not ideal conditions in which to perform an upgrade.
Having had no luck, my Grandad and I decided to take the computer with us 
to the Atari show in Birmingham in December, which was in a few weeks 
time. The guys from Compo who were fitting the upgrades at the show 
managed to make it work and my Grandad is now the happy owner of a 1Mb 
STFM.