c184-au@holden.Berkeley.EDU (Dan Filner) (04/14/89)
In response to the question of whether reading in a SS disk, rearranging
the tracks in a DS manner, and rewriting the whole thing to disk is a good
thing...
I offer an alternative which I personally have been using for about two years
on my old 520 with DS, my new 1040, and my extra 5.25" 720K drive
Presenting here for your enjoyment and hopefully benefit.
:::: The Tim Mensch Special.
This hardware modification will allow you to use BOTH SIDES of a disk which
is current formatted Single sided. (Read 'copy-protected games').
This does, of course, require a double sided drive. If you don't have one,
you are definitely in need of one. Go buy one at once.
(Background info)
In the cable that connects the floppy drive mech to its nearest computer
component, there is a single pin that specifies SIDE SELECT. When the
Atari is using a SS drive, this signal is always (low/high : I don't
remember). When a DS drive is called into play, this signal alternates
depending on which side the computer is trying to read/write.
Nearly all games come on SS disks, wasting 50% of all disk storage and
causing immense numbers of floppies floating around.
(The tricky part)
Install a switch. The idea is, connect the DRIVE MECH side select pin to
either the Atari's side select pin or GROUND. (You decide!) That is, in
one swtich position, say, 'up', the drive is connected through to the Atari
just as it is now. NO DIFFERENCE IN OPERATION! In the second position,
'down', the drive gets GROUND as its side select, forcing it to write
to SIDE 2. The Atari still thinks that its signal is getting through...
so the computer acts just as though you have a single sided drive!
Uses of this nifty hardware mod :
1. Primarily backups/archives/pirate copies of protected software.
TWO SS DISKS worth of software can be now put on ONE DS disk.
Immediate savings of 50% disks.
2. EASE OF USE in multi-disk games. Copy DISK II of Game X onto SIDE 2 of
Game X Disk I. Thus, when "Please Insert Disk II" comes up, all you need
do is flip the switch! (Some games check for media change so you still
have to pop the disk in and out.. ugh ugh ugh.)
3. "Partition" your double sided floppies. (Makes two single sided disks
out of a double sided disk)
DISCLAIMER : I take no responsibility for anything that happens to anyone
as a result of trying this. I'm sure it will void thy <hahaha> warranty.
Since I don't remember offhand which pins in the cable need to be spliced
together, I won't give any more detailed instructions as to how to do this...
hardware hackers of the appropriate caliber should be able to easily
reconstruct the entire setup, given info on cabling to the drives. Or just
write me mail and ask me how to do it. I've 'done' three of my own drives
and about three other people's. You could get someone else (say me) to
do it for you, but this is an easy enough hack that anyone who can solder
can do it.
I have had NO trouble whatsoever with this mod over the years. Since it
is totally transparent to the ST, no software will not work with it.
(I can imagine cases where a protection scheme might try to access the
otherwise unused back side of a disk, but that wouldn't work on a SS
drive anyway...)
RECOMMENDATIONS : When you drill a hole into the case of your 1040/520F,
Don't put the switch in the obvious place, one the side of the computer,
next to the drive itself. You will note that this is in the TOP half
of the plastic case and the cable to which
you must run wires is in the BOTTOM half. Thus, every time you need to
open your machine up, you will forget and yank the two apart, thus causing
significant strain on your switch/cables/soldering job. I have just moved
my switch around to the back of my machine where the RF modulator should
have been.. for SF314 mods, I'd say, put it in the front, on either side
of the disk slot. It's up to you.
HISTORY : This was thought up and tested by Tim Mensch, an awesome
programmer and fairly good hardware dude. Thanks, Tim!
(Tim and I go way back...)
There. I think I've said everything. Get a SPDT switch, (I got mine at
Radio Shack)... sever the appropriate pin of the ribbon cable to the drive,
center switch connection to the DRIVE side select, one side to
the atari side select, and one side to a ground. (Odd numbered pin in the
34 pin cable will do fine) (I think it's pin 32 of the 34 pin cable that is
side select.. look it up, and double check before doing anything drastic.)
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Dan Filner "We're on the moooooon!"
c184-au@holden.Berkeley.Edu
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