HELP Gauntlet I and II

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J.D. Frey

Nov 2, 1998, 3:00:00 AM11/2/98

I have Gauntlet one and two, but my gauntlet 2 cab is almost
completely destroyed beyond repair. I would like to have
both games in the same Cab. Is that possible, and is there
a snazzy way to do it? If you have any info on this please
email me

Ron Michallick

Nov 3, 1998, 3:00:00 AM11/3/98

It is said that it can be done, but the information to do such a
task is missing the slapstic hack. Many have tried and to the
best of my knowledge all have failed. Its just a myth; I've lost
my faith.

Jay Whip Grizzard

Nov 3, 1998, 3:00:00 AM11/3/98
Ron Michallick <> writes:

Not -everyone- has failed.



Jay Whip Grizzard

Nov 3, 1998, 3:00:00 AM11/3/98
to (Jay "Whip" Grizzard) writes:

> > It is said that it can be done, but the information to do such a
> > task is missing the slapstic hack. Many have tried and to the
> > best of my knowledge all have failed. Its just a myth; I've lost
> > my faith.
> Not -everyone- has failed.

Okay, okay, so I'm not going to be this much of a bastard.

I dug into my backups and found the documentation I wrote some number of
years ago about doing this hack.

When I get some time, I'm going to grab my 10A ROM and read it in and make
it available to the 'net at large. This is the hacked ROM needed to make
this whole project work.

I -may- get adventerous and take my board out and put up some pictures
of how the whole thing is put together. No promises, but I'll see what I
can do.

I can absolutely guarantee that this hack DOES work -- I have it up and
working and anyone that's local to San Jose is welcome to come by and
let me put my money where my mouth is. This hack has worked absolutely
flawlessly since I did it several years back. It's a pain in the ass
to pull off, but it DOES work. I promise.



Nov 6, 1998, 3:00:00 AM11/6/98
I picked this up about a year ago.
I might have more infos somewhere on my hard drive.
Oh yes, I also have the incredible Level Editor for G2 by Eric Crabill
(thanks again Eric!)

> >
> > Not -everyone- has failed.
I DO NOT CLAIM THAT I DID ANY WORK (apart from publishing it here).
But I am happy to give it to the group.
I think the ones who did this great job were:

Written by Jay 'Whip' Grizzard

Support from Eric Crabill

<Bild>ROM Editing Tools
<Bild>How To Bypass The Slapstic
<Bild>How To Create A Dual (I/II) Game


ROM Editing Tools

Download the file for a suite of tools to edit your Gauntlet II
ROMs. Unzip it using the -d option to keep the directory structure intact.
The contents of this file include:

<Bild>An alphanumeric ROM editor.
<Bild>The Gauntlet II Maze Editor.
<Bild>A vastly improved ROM Builder.
<Bild>A prototype character attribute editor.
<Bild>Lots of sample levels.

You don't even need an EPROM programmer to make use of these tools! If you
have Neill Corlett's Multi-Gauntlet Emulator, you can use the modified ROMs
from my tools, too.

You may find the following image useful when designing mazes. Special
thanks go out to Dave Hallock for putting this together. I'd also like to
thank everyone who helped test these programs.

These tools are property of Eric Crabill. I grant you permission for
personal, non-commercial use of these tools. To use this software, you must
have a PC with Microsoft Windows. It runs best on a large screen so you can
see the whole editor at once.

<Bild>Idiot Warning: No, you are not an idiot, I am. So listen to my careful when you are changing ROMs on your precious Gauntlet
II board. Once, in all my excitement, I plugged the new ROMs in backwards
and when I turned on the power there was a bright incandescent glow through
the quartz windows. So bright, in fact, that it was visible through a
label. So, do not do this. Good thing I have three of these boards! Also,
you can definately expect a ROM Error when you power up. Don't let it
bother you, though. Everything will still work.


How To Bypass The Slapstic

A long time ago, I tried to buy a slapstic from one of Atari's distributors
because I wanted to copy the ROMs instead of buying the entire conversion
kit (can I go to jail for thinking this?) When I was quoted a price of
$350, the same price as the entire kit, I gave up and bought the whole kit.


Whoever made this should burn in hell!!!

These days, I don't think conversion kits are available in large numbers,
so what do you do if you want to convert your Gauntlet I to a Gauntlet II?
Or even more important, what if your slapstic breaks? You really have three

<Bild>Scrounge the net looking for 137412-106.
<Bild>Reverse engineer the slapstic to build a replacement.
<Bild>Run your Gauntlet II without the slapstic.

I guess it is somewhat known that you can install the Gauntlet II ROM set,
then play without the slapstic. You will get as far as level 6, then your
chances of getting past that are about 25% compounded per level. In
addition, the attract mode maze is messed up, as are the legends and the
high score table.

Because I am insane, I have figured out how to fix this problem. You need
to do two things, and they are quite simple. The first is that you need to
replace the ROM at location 10A (136043-1105) with this new, carefully
handcrafted replacement. It is a 27128.

The next step involves some hardware. Pull out the slapstic which you don't
have. Then, get a 20 pin machined socket and solder these two wires (on the
top, silly): From pin 4 to pin 10; then from pin 5 to pin 9. Plug this
socket into the slapstic socket. If you don't have spare sockets laying
around then you could (I suppose) just jam the wires into the socket on the

<Bild>Please make sure that you insert the socket correctly, not backwards,
or you will really be sorry. Now you can turn on the machine. It will work,
and you can just ignore the ROM checksum error when you see it. This is
because one of the ROMs has been modified.


How To Create A Dual (I/II) Game

Written by Jay 'Whip' Grizzard

Support from Eric Crabill

If you're like most folks who like Gauntlet, you like both Gauntlet I and
Gauntlet II -- admit it, they've both got their good points and bad points.
Also, if you're like most people, you don't have two Gauntlet cabinets
lying around (I used to!--Eric) in your dorm/apartment/house or whatever.
And finally, if you're like most people, you probably don't want to have to
do an entire board swap (or ROM swap) just to switch between the two.

Well, now there is a way to play both Gauntlet and Gauntlet II using the
same board, with a single switch-flip toggling between the two.

<Bild>This hack is NOT intended to allow for easy pirating of Gauntlet or
Gauntlet II software -- please don't use it as such. Also, we take NO
responsibility for any damage you do to your Gauntlet board (or anything
else) while attempting this hack. Though the chances of actually damaging
something are fairly small, they are there, so make sure you know what
you're doing before you start hacking!

The theory: Gauntlet I and Gauntlet II use absolutely identical hardware.
The only differences are some of the ROMs used, and the slapstic copy
protection chip. If the ROMs were replaced with double-sized ROMs, with the
highest address line wired to a switch, flipping that line between 5v and
GND would, essentially, give two completely different ROM images. Other
than the copy protection, this gives two completely functional games on one

The hack: We'll assume a few things in this documentation. First off, we'll
assume that you're at least semi-technichally competent. Second, we'll
assume you have Gauntlet I and Gauntlet II ROM images. Third, we'll assume
you have access to an EPROM burner. We'll also assume that your board is
the same as ours, and that you are starting from a Gauntlet II board.


First, get your parts together; you will need:

<Bild>4 27256 EPROMs (300ns or better)
<Bild>7 27512 EPROMs (300ns or better)
<Bild>1 2816 EEPPROM
<Bild>Various machined sockets (2 or 3 for each chip)
<Bild>Lots of wire (awg 30 is good)
<Bild>A switch


Get your ROMs ready.

Some of the ROMs we won't be changing -- in particular, the ROMs in
locations 9A, 9B, 6A, 6B, 1B, 2B, 1C, 2C, 1M/N, 2M/N, 1P, and 2P will
remain the same as they were in Gauntlet II, so don't do anything with
those. (We're keeping 9A, 9B, 1B, 2B, 1M/N, and 2M/N because they're the
same in Gauntlet and Gauntlet II. We're keeping the rest because they're
ONLY used in Gauntlet II, and Gauntlet doesn't mind them being around). If
you are starting from a Gauntlet board (not Gauntlet II) then you will need
to add the appropriate Gauntlet II 6A, 6B, 1C, 2C, 1P, and 2P ROMs.

The chips we will be replacing are those in 13A, 10A, 10B, 7A, 7B, 1A, 2A,
1L, 2L, 6P, 16R, and 16S. The new images for all of these (other than 13A,
which is the EEPROM that stores scores and settings) can be created fairly
simply. The EEPROM doesn't need to be initialized.

For all the chips other than 10A, simply read in your original Gauntlet I
and II ROMs, and burn new ones, into double sized chips, with the Gauntlet
I ROM on the low half and the Gauntlet II ROM on the top half. For 16kbyte
images (27128), the double-sized ROM to burn is the 27256, and for 32kbyte
images (27256), the double-sized ROM to burn is the 27512. If you are
working with files, an easy way to merge two ROM images is to use the
MS-DOS copy command, like this:

copy /b some_gaunt1.rom + matching_gaunt2.rom new_merged.rom

For the 10A ROM, you must use modified ROMs that work around the slapstic.
For Gauntlet II, use this file and for the original Gauntlet, use this
file. Again, Burn the G1 one low, the G2 one high...


Install the ROMs.

Once you have your images, you need to wire up a way to switch the high
address line on these chips between 5v and GND. You may choose your own
method (it could be as simple as simply bending up a pin on the EPROMs and
soldering wires), but here's what we personally recommend:

Build a stack of 3 (or 2) sockets; use -MACHINED- (not leaf) sockets. On
the bottom two of the stack, remove the socket pin corresponding to the
chip pin for the highest address line on that chip. On the topmost socket,
solder (or wrap) a wire, and daisy-chain that wire from socket to socket,
in essence shorting the high address lines of all the special EPROMs

I personally used wire-wrapping, building the sockets one at a time,
working from the sound ROMs (up in the corner with the power connector)
down around to the left, finishing with the ROM in the middle. Order
doesn't matter, really. In retrospect, I probably would have started with
the ROMs at 10A, then worked around to the alpha ROM (in the middle) and
finished with the sound ROMs.

You probably want to check your sockets with a meter before you install
them -- Obviously, the high address pin from each chip should be connected
to the wired up pin on all the other sockets, and NO OTHER PINS.

Which pins? Well, on 27256's, the high address line (A14) is on pin 27. On
27512's, the high address line (A15) is on pin 1. On the 2816, you actually
want to tie -two- pins (the upper two address lines) together, to give you
two 1/4-sized chunks (and two unused 1/4 sized chunks). Those two pins are
19 and 22. [For the un-initiated, IC pins are numbered, starting at 1,
counter-clockwise from the notch on the chip.]

For reference, the 2816 is in location 13A, the 512's are in locations 16S,
7A, 7B, 1A, 2A, 1L and 2L. The 256's are in locations 16R, 10A, 10B, and


Defeat the Slapstic

Once that's done, you'll have an almost-functional machine. Remember how we
mentioned copy protection above? Well, the copy protection for both games
is -different-, so we've had to work around it by altering parts of the
ROMs. However, this workaround also requires just a touch of hardware
support -- you need to replace your slapstic, the chip in location 10C.
Grab a 20-pin machined socket, and solder a wire between pins 4 and 10,
then between pins 5 and 9, and plug this into where the slapstic used to


Double Check Everything

<Bild>and double check the board and your wiring before you turn on the
power. If all is well, you'll have a switcharoo game. If the high address
lines are grounded, you'll get Gauntlet, if they're at 5v, you'll get
Gauntlet II. I, personally, used those quick-plug style female connectors,
plugged into the two test points (5v and GND) up next to where the player
joysticks plug in. You're welcome to get it wherever you want, run it
through a switch, and enjoy.

Mike Patterson

Nov 7, 1998, 3:00:00 AM11/7/98
tobias ( wrote:
: I picked this up about a year ago.

: I might have more infos somewhere on my hard drive.
: Oh yes, I also have the incredible Level Editor for G2 by Eric Crabill
: (thanks again Eric!)
: tobias

There are apparently some files that went with this document. Namely the ROM
image for the 27128. (also the editors, etc, but in building a dual-boot
system, you don't seem to need any other custom files)

Any idea where these files can be found?

: > >
: > > Not -everyone- has failed.

: Support from Eric Crabill

: ------------------------------------------------------------------------

: ROM Editing Tools

: ------------------------------------------------------------------------

: <Bild>

: ------------------------------------------------------------------------

: Support from Eric Crabill

: <Bild>

: <Bild>

: Get your ROMs ready.

: <Bild>

: Install the ROMs.

: <Bild>

: Defeat the Slapstic

: <Bild>

: Double Check Everything

Michael K Patterson, HP Software Engineer
My opinions do not represent those of HP. If they do, it's coincidence.

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