Kabutogani! (or the XE‑1AP Analog Joypad)

Way back in the 1980s, the days of the exciting home computer and game console boom, Micom Soft introduced their XE‑1 line of game controller peripherals. From the humble XE‑1B two-button joystick for Japanese home computers, to the XE‑1ST2 switchable 4-way/8-way joystick with support for FM Towns and Sega consoles, to the fully programmable XE‑1SFC Super Famicom stick (with an LCD screen), there was something for everyone. They were known for their excellent build quality, unconventional features, and of course their rotating button clusters.

The XE‑1AJ Intelligent Controller is possible the most impressive, and definitely the most imposing, member of the product line. Also sold as the Sharp CZ-8NJ2 Cyber Stick, it is a large HOTAS flight controller for desktop use. Just the size and weight are impressive: it takes up a lot of space on your desk, the stick and throttle shafts are metal, it’s clearly built to last. It features an analog stick and throttle, a thumb button and trigger on the stick, a thumb button and two-way rocker switch on the throttle, and five panel buttons. The stick button and trigger functions can be exchanged, auto-fire is supported for the stick button and trigger, and a variety of special modes can be enabled by holding panel buttons while pressing the reset button. If that isn’t enough, the stick and throttle positions can be reversed for left-handed use. It can even be switched to digital mode for games that don’t support analog controls.

With the launch of the Sega Mega Drive in 1988, someone at Micom Soft must have started wondering, “How can we bring all the fun of the XE‑1AJ to couch gaming?” The result was the XE‑1AP joypad. Brought to market in 1989, the XE‑1AP was the first control pad to feature analog controls. It was nicknamed the horseshoe crab (kabutogani in Japanese) due to its shape. It actually succeeded in packing all the key functionality of the XE‑1AJ into a hand-held controller, and even added a few features. In many ways, it is the ancestor of modern game controllers, pioneering many features that were only popularised years later. Its features included:

  • Ergonomic shape with grip handles.
  • Analog stick controlled with left thumb.
  • Analog throttle controlled with right thumb; could be rotated through 270° for horizontal or vertical movement in either direction.
  • Two shoulder buttons on each side.
  • Two face buttons on each side, plus Start and Select buttons.
  • Auto-fire support for the right shoulder buttons.
  • Modes to support Japanese home computers and Sega consoles.

The design of the Sega Saturn 3D Controller was directly influenced by the XE‑1AP – the similarity is quite striking. The Saturn 3D Controller was further developed into the Dreamcast controller, which in turn served as the inspiration for the Xbox controller. The Xbox controller was ridiculed for being excessively large, but the XE‑1AP is actually bigger. This is at least partly for practical reasons: it needs space for its 42-pin plastic DIP Fujitsu MB88513 microcontroller and the rest of the components that make it work. Electronics used to be a lot bigger.

It’s interesting how obscure the XE‑1AP has become. Perhaps poor marketing is partly responsible. It was supported by several Mega Drive, Mega‑CD and 32X games, but only mentioned in the Japanese versions of the manuals. The export versions of the manuals never mentioned the XE‑1AP, despite the export versions of the games supporting it in most cases. Micom Soft sold an adapter that allowed the XE‑1AJ or XE‑1AP to be used with the NEC PC Engine. Although five PC Engine games supported analog controls, this was never heavily promoted. Three of them don’t even give any indication when a supported analog controller is detected. The high price probably didn’t help either, but I can’t help wondering what could have happened if the XE‑1AP was promoted more heavily, leading to more adoption, and hence more games developed with support for it.

I recently added support for the XE‑1AP to MAME. In typical MAME fashion, the emulated XE‑1AP can be used with compatible games on several systems, including the Sega Mega Drive, NEC PC Engine, Sharp X68000 and FM Towns families. I’ve also written some basic instructions for using the controller with some of the games I tested.

Sharp provided assembly language source code for an X68000 driver for the XE‑1AJ and XE‑1AP. This may be the reason the X68000 has the best software support, with over a dozen games making use of analog controls. The Mega Drive and PC Engine games with XE‑1AP support use a similar algorithm to read data from the controller, but the games developed by CSK Research Institute for FM Towns use a different approach. Although this meant more effort getting the emulated controller to work across all the platforms with compatible software, it does mean we can infer more details about the controller’s behaviour.

You will need to manually assign controls to the XE‑1AP inputs in MAME to get a good experience, due to the number of controls and how different the layout is to common controllers. Here are some tips:

  • The XE‑1AP plugs straight into controller ports on the Mega Drive, X68000, and FM Towns.
  • For the PC Engine, you need to plug it in via the XHE‑3 PC joystick adapter. It’s the default peripheral for the XHE‑3, as it’s the most useful thing you can connect to it.

  • X68000 games expect the XE‑1AP to be connected to the first joystick port. Keep in mind that in MAME, the X68000 mouse counts as a “player”, so the XE‑1AP on the first joystick port will use player 2 controls by default.
  • Most Mega Drive games expect the XE‑1AP to be connected to the first controller port. Night Striker for Mega‑CD is an exception – you need to connect the XE‑1AP to the second controller port, and use a regular control pad connected to the first controller port to select analog mode.
  • FM Towns games require you to connect the XE‑1AP to the second controller port, and use a Towns Pad connected to the first controller port to navigate the menus and select analog controls. CSK Research Institute games require you to change the XE‑1AP’s Interface setting to MD in MAME’s Machine Configuration menu.
  • A lot of games only detect controllers on start, so if you switch the Mode from Analog to Digital or vice versa and controls stop working, you might need to restart the emulated software.

Assuming you have fairly standard settings, here are some example command lines for starting different games with the XE‑1AP:

% mame x68000 -joy1 xe1ap shangon
% mame megadriv -ctrl1 xe1ap smgp2
% mame fmtowns -ramsize 2M -pad1 townspad -pad2 xe1ap aburner3
% mame pce -ctrl pcjoy -cartridge scdsys -cdrom forgottnj

For what it’s worth, here’s my take on some of the games I tested:

After Burner II for X68000, Mega Drive and PC Engine
It’s definitely a lot easier to hit oncoming planes with your Vulcan guns with precise control of your flight attitude. It feels like a lot of the controller’s features go unused. Note that for the X68000 version, you need to press OPT.1 on the keyboard (in MAME, this is assigned to PrtScr by default) at the title screen to enable joystick controls. There’s nothing on the screen to tell you to do this, and no visual indication when joystick controls have been enabled.
Ayrton Senna’s Super Monaco GP 2 for Mega Drive
This one feels like it’s been thought out very well: the shoulder buttons are your paddle shifters (left to shift down, right to shift up), you control the accelerator and brakes with the stick using your left thumb, you rotate the throttle to be horizontal and use it to steer with your right thumb, and you press E1 or E2 with your left thumb to make a pit stop. You’ll need to change your input assignments in MAME to make this game playable. With an Xbox-style controller, you can assign the X axis of the right stick to the throttle to get close to the original setup. It feels much better with analog steering – staying on the track is a lot easier.
Thunder Blade for X68000
With analog controls, you get the best possible experience in this game. You can hover and land, just like you could in the arcade version. Assigning the throttle to the left trigger on an Xbox controller lets you fly with your left thumb and index finger, leaving your right thumb and index finger free for controlling weapons. If you assign the throttle to “Joy 1 LT -” (squeeze and release the trigger three times when assigning the input), releasing the trigger hovers and squeezing it flies forward. Assign the right trigger to B or B’ to fire the cannon, and and assign a face button to A or A’ to fire missiles.
Super Hang-On for X68000
Nothing surprising, just responsive analog controls. This game lends itself well to assigning the left and right triggers on an Xbox controller to the brakes and throttle – they even correspond to the positions of the brake lever and throttle twist grip on a motorbike. The correct assignment is “Joy 1 LT Joy 1 RT Reverse” (squeeze and release the left trigger once, then squeeze and release the right trigger four times when assigning the input). Remember not to assign the triggers to other buttons at the same time, or you won’t be able to select stages and music with the brake.
Taito Chase H.Q. for FM Towns
For me, analog steering took this game from being almost unplayable to great fun. If you prefer to use analog triggers or pedals for the accelerator and brakes, see the notes about Super Hang-On for how to assign the throttle. The turbo boost is button D, which makes perfect sense as the throttle thumb button on an XE‑1AJ, but doesn’t make quite as much sense as the lower left shoulder button on an XE‑1AP. If you’re using a thumb stick for the accelerator and brakes, it’s probably most natural to assign it to clicking the stick down, or maybe the (upper) shoulder button on the same hand as the stick you’re using. If you’re using triggers for the accelerator and brakes, using a face button for turbo boost might be a good choice. Remember to change the Interface back to Personal Computer in MAME’s Machine Configuration menu if you previously changed it to MD to play a CRI game.
After Burner III for FM Towns
This is a CRI game, so you need to change the Interface to MD in MAME’s Machine Configuration menu, but it’s worth it, because this is a highlight! It doesn’t even pretend to be accurate flight simulation, but you wanted accurate simulation, you wouldn’t be playing an After Burner game. You can roll all over the place, and it’s an awesome feeling to hold C or D, slam the throttle, and watch the After Burner Level gauge fill while you shake off a bogie on your six. It’s also got more variety than After Burner II, with stuff like ground attack levels where you plink tanks.
Operation Wolf for PC Engine
This game actually does tell you on the title screen when it’s recognised an analog controller. It gives you absolute position aiming using the stick. Definitely a lot faster and more accurate than moving the reticle around with a D-pad.
Forgotten Worlds for PC Engine Super CD-ROM²
Remember to insert the Super CD-ROM² System HuCard as well as the Forgotten Worlds CD. You’ll need to assign a key to the Run button on the joystick adapter, because the Super CD-ROM² System software won’t recognise the Start button on the XE‑1AP, and you’ll need to press it to start the software on the CD. This is the other PC Engine game that lets you know it’s detected an analog controller on the title screen. This one was a really pleasant surprise for me. The analog movement and aiming controls felt beautiful. It probably helps that it has pretty graphics and a lovely CD soundtrack, too. Load times are noticeable, but not long enough to be irritating.
Out Run for PC Engine
As with other racing games, it’s easier to stay on the track with analog steering. Using the analog throttle for the accelerator while using buttons for the brakes was an interesting design choice – you can press any of the A/B/C/D/E buttons to brake. If you decide to reassign the throttle to an analog trigger or pedal on an Xinput controller, you’ll need to assign it to the negative half of the axis. For the right trigger on an Xbox controller, squeeze and release the trigger until it shows “Joy 1 RT -” (three times) when assigning the input, and make sure you don’t have the same trigger assigned to any of the buttons.
Thunder Blade for PC Engine
This one’s a disappointment – it’s no different to using a digital game pad. Move the stick a little and you don’t move; move it a bit further, hit the threshold, and you’re moving at full speed. Also, the weapon controls are reversed compared to the X68000 version, with A firing the cannon and B firing missiles. I guess it’s nice of them to make it recognise the controller in analog mode, but it would have been even nicer if they’d made better use of it.
Musha Aleste for Mega Drive
This game is infamous for being unplayable with the XE‑1AP in analog mode. The stick controls your absolute position on the screen, which really doesn’t work for a shooter like this – it’s far too twitchy. Surprisingly, the game actually becomes playable if you assign mouse axes to control the stick, feeling similar to PC shooters like Raptor: Call of the Shadows.

XE‑1AP support isn’t the only controller-related improvement coming in MAME 0.251 – other things that made it in this month include:

  • Pluggable controllers for the Sega Mega Drive and SG‑1000 families.
  • Pluggable controllers for the NEC PC‑6001, PC‑8801 and PC‑88VA families.
  • Pluggable controllers for the Sharp MZ‑800, MZ-2500 and X68000 families.
  • Sega Mouse (2-button) and Mega Mouse (4-button) support for the Mega Drive family.
  • Sega Tap/4-Player Adaptor/Team Player support for the Mega Drive family.
  • Support for an ATmega-based paddle controller that works with export versions of the Sega Master System.
  • Mouse support for the PC Engine family.
  • Support for the Konami Hyper Shot controller (although it’s somewhat pointless in emulation).

This entry was posted on Saturday, 24 December, 2022 at 7:57 am and is filed under MAME, Technology. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

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