Irem M-92 goodness

Just received an Irem Skins Game (Major Title II) board set from Quarterarcade http://www.quarterarcade.com/Default.aspx , props due to them for the excellent service, immediate dispatch, well packed, good communication and it turns out the board set is NOS never used, the only marks on the gold plated jamma edge would have been the pre-test (at a reasonable price imho $60)
I have bought other boards from them before (Galaxians) and been happy with the deal.


Known Irem M-92 boards:

Blade Master / Cross Blades!
Dream Soccer 94
Gunforce
Gunforce 2 / Geostorm
Hook
In The Hunt / Kaitei Daisensou
Lethal Thunder / Thunder Blaster
Major Title 2 / The Irem Skins Game
Mystic Riders / Gun Hohki
Ninja Baseball Batman / Yakyuu Kakutou League-Man
Perfect Soldiers / Superior Soldiers
R-Type Leo
Undercover Cops


Board set image (Blade Master)

The main reason for getting the game is that I already had a Gunforce and more importantly In The Hunt boards with faulty mother (A) boards and good rom (B) boards.
Now have 3 working games - always wanted the classic ITH in the collection as it is one of my all time favs.

The beautiful thing about ITH is the similarity with R-Type and the MS series written by the same people (irem/nazca) An under water shmup was a new concept and it worked. Captain your own submarine instead of a space ship. The gfx are excellent but the sound could be better.

An R-Type would be awesome.

Thought that I may share a few things I have discovered about the M-92

On the main board there is a jumper J3 with positions W...centre....B. If this is in the wrong position there will be missing sprites.
Correct position for the games that I have, is between centre and B pins. (Not sure what the W and B stand for ?)
Spent some time looking for a sprite problem when it was a missing jumper not on the board I got from Quaterarcade I should add.

The socketed PLCC custom IC2 ( read IC 8 on ITH rom board) on the rom board is different for each game. I swapped between ITH and GF (not realising this at the time) to eliminate the device, turns out the games still work with the wrong cutom IC but with sound issues, as the sound encrypion happens there, and in the case of ITH the attract mode runs for the first two stages then crashes, otherwise it plays.
This could be a trap for young players working on an M-92 board that has been "got at" before.

Correct custom PLCC ICs at IC2 (actually IC8 on ITH - thanks Testocules for correcting that) on the rom board.

Gun Force.....08J27261A1
Irem Skins.....08J27291A7
In The Hunt....D8000011A1

The RAM OK, ROM OK at start up does not really meen much; with faulty ram/rom the OK diag message will still show. This is common on many boards.

Another interesting thing about the M-92 is that the audio works fine in an MVS wired cab, will have to check the output stage and find out whats going on there. The pin out seems to be straight jamma. It is an issue with the audio output stage I think. Maybe one side of the speaker is grounded ?
I wouldnt recommend running these boards in an MVS cab at this stage.

Manuals at crazykong.com here
http://www.crazykong.com/manuals/DreamSoccer94.man.pdf
http://www.crazykong.com/manuals/GunForce.man.pdf
http://www.crazykong.com/manuals/InTheHunt.man.pdf
http://www.crazykong.com/manuals/MajorTitle2.man.pdf
http://www.crazykong.com/manuals/UndercoverCops.man.pdf


More info here http://www.system16.com/hardware.php

CPU : V33 @ 9 MHz, V30 @ 7.159090 MHz
Sound Chip : YM2151 @ 3.579545 MHz, GA20 @ 3.579545 MHz
Other Chip : GA21, GA22

--------------------------------------------------------------------------------
The sound cpu and the sprite chip are on the game board rather than the main board and can differ between games, see individual games for details.
Each game has an encrypted sound cpu.
--------------------------------------------------------------------------------
Hardware Abilitys : 3 scrolling playfields, 512 by 512.
Each playfield can enable rowscroll, change shape (to 1024 by 512), be enabled/disabled and change position in VRAM.

Tiles can have several priority values:
0 = standard
1 = Top 8 pens appear over sprites (split tilemap)
2 = Whole tile appears over sprites
3 = ? Seems to be the whole tile is over sprites (as 2).

Sprites have 2 priority values:
0 = standard
1 = Sprite appears over all tiles, including high priority pf1

Raster interrupts can be triggered at any line of the screen redraw, typically used in games like R-Type Leo to multiplex the top playfield.


I have a Hook board too but that is beyond repair, also a working bootleg R-Type. Irem rocks.

As for Irem Skins/ Major title 2, it is not a bad golf game for its era, Im starting to warm to it.

Anyone else here had much to do with the Irem boards.

...lucky bastard. You have In The Hunt. If you ever want to sell that, hit me up...

black_7 said:

...lucky bastard. You have In The Hunt. If you ever want to sell that, hit me up...

Click to expand...

Never, its going to the grave with me


Edit: a bit of trivia, IREM - International Rental Electronic Machines Co. started in 1978.

black_7 said:

...lucky bastard. You have In The Hunt. If you ever want to sell that, hit me up...

Click to expand...

Do you have any other irem games

lol, I just bought this game last week!

ttooddddyy said:

On the main board there is a jumper J3 with positions W...centre....B. If this is in the wrong position there will be missing sprites.
Correct position for the games that I have, is between centre and B pins. (Not sure what the W and B is for ?)
Spent some time looking for a sprite problem when it was a missing jumper

Click to expand...

I looked at mine and confirmed the position of J3.

ttooddddyy said:

In The Hunt....D8000011A1

Click to expand...

Is this info held within the chip?

Welcome to the club, the IC part # is printed on the device.

I found the problem, on my ROM board "the socketed PLCC custom IC2" is IC8. On my board, IC2 is the furthest to the right, top row - IC8 is one from far left, top row. Are our boards different, or am I getting something wrong?

I will take a picture

I will post a pic as well.

Testocules said:

I found the problem, on my ROM board "the socketed PLCC custom IC2" is IC8. On my board, IC2 is the furthest to the right, top row - IC8 is one from far left, top row. Are our boards different, or am I getting something wrong?

Click to expand...

I stand corrected (no need for a picture) it is indeed IC8 on the ITH and IC2 on Gunforce and Irem Skins.

Good to hear that they are the same after all. Thanks for the great info in your thread.

On a related note, In the Hunt is somewhat of an odd board...I'm not sure how it should be mounted. The larger mainboard has a heat sink that is too thick to allow typical feet to support it. Mounting feet on the Rom board would place it in what appears to be an inverted position....Is it supposed to sit vertically? Can you tell me how it was intended to be mounted inside a cab?

The mounting feet screw to the B board, there are 4 seperate holes for them.
So the A board is on the outside when screwed into the cab.

Someday I'll pickup a Ninja Baseball Batman board, it's a great one. Haven't seen that one for sale in a while.

R-Type Leo was also an M-92 game. I was never a big R-Type fan, for me this is the best title in the series.

I had a Gun Force PCB for a while but sold it. That's the only Irem board I've ever had

Only played Leo on mame, but it looks awesome.
Neostorm aka Gunforce 2 looks ace too.

Agreed, Gunforce 2 does look good. Do I detect a slight Robocop influence? One of the enemies looks like ED-209, after you destroy it, the remaining legs even fall over like in the movie. In the Hunt always seems to get credit for being a predecessor to Metal Slug, but Gunforce 2 is a much more obvious cousin to the Slug series.

Armored Police Unit Gallop looks interesting as well, not sure I ever saw either of these games back in the 90's

According to wiki Hook is M-99 hardware ?. Im almost certain its a M-92. That has to be a typo ?
http://en.wikipedia.org/wiki/List_of_Irem_games. I have a Hook somewhere and sure it is a M-92.

System 16 has Hook listed as M-92 and seeing as it was released in 1992 that would make sense.

All is not so well with ITH just pasted below a post I made on aussiearcade



To cut to the chase, I had a good Gunforce and (what I thought) In the Hunt "B" boards but no good working "A" board to plug them in to.
So I bought a working Irem Skins in order to have 3 working Irem games. The main reason was to get the ITH going which is one of my favorite games.

Turns out ITH has intermittent sound probs, it is definately on the B board as Gun Force and Irem Skins work perfectly on the common mother board.

Problem is that the sound cuts out intermittently, when audio is lost - it stays lost untill the game is reset.
There seems to be a thermal aspect to this. For instance if run from cold the game may get through 3 stages before loosing sound, if rebooted (still warm) it will probably only get to stage 2. Sometimes it will run for hours ? If rebooted imeadiately there may be no sound at all from start up. One thing for sure - it always starts up with sound from cold.

I have tried heating and freezing but that reveals nothing. Even tried heatsinking the two customs, this has no effect on average run time before the sound dies. Nothing seems warm to the touch.
No apparent dry joints - I can bash about the board without bringing the fault on.


edit: could always dust down the logic probe, but looking for an easy way out if anyone may have struck this before on the M-92.
I hope it doesnt turn out to be one of the customs or a PAL. Doubt it.

Have you tried replacing any of the caps? I don't have any experience with this specific hardware, but it sounds like a cap related problem I've encountered before elsewhere.

You should put this in the tech forums and let the guys with more experience weigh in.

You're forgetting to mention that Skins Game is a precursor to Neo Turfmasters. Although IMO it's really nowhere near as enjoyable, if you're a fan it's worth playing to see the influence it had on NTM.

astrodan88 said:

Have you tried replacing any of the caps? I don't have any experience with this specific hardware,.

Click to expand...

There are no electro caps on the rom board. The audio out stage is on the mother board which is confirmed OK. This is a digital issue imho. And it definately seems heat related - but have been unable to smoke it out. I say this not because anything seems to run hot - its just the nature of the fault symptom.


Gun Force "B" board, notice the two customs, 1 smd the other plcc.

DanAdamKOF said:

You're forgetting to mention that Skins Game is a precursor to Neo Turfmasters. Although IMO it's really nowhere near as enjoyable, if you're a fan it's worth playing to see the influence it had on NTM.

Click to expand...

Yes indeed

This is the first Nazca game written for the Neo-Geo MVS. Nazca was formed by Irem ex members, which is the reason why Neo Turf Masters adopts many of the graphic and gameplay aspects of Irem's "Major Title/Irem Skins" series.