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Air duel works fine & is a simple rom swap.

There's another Load of games too patched for m82 by gadgetfreak, Cosmic cop, X Multi, Dragon Breed, Hammerin harry etc.

Also An 8 in 1 switcher in development, all games run but a couple need some work in the GFX rom switching department.
A schematic will be posted one day so you can do this yourself with a few wire mods.
Oh - that is very nice info, thanks! I have played enough Major Title, ready for something else :)
Is the 8in1 switcher on this forum somewhere? Can't say I have seen it before.
 
Air duel works fine & is a simple rom swap.

There's another Load of games too patched for m82 by gadgetfreak, Cosmic cop, X Multi, Dragon Breed, Hammerin harry etc.

Also An 8 in 1 switcher in development, all games run but a couple need some work in the GFX rom switching department.
A schematic will be posted one day so you can do this yourself with a few wire mods.
Oh - that is very nice info, thanks! I have played enough Major Title, ready for something else :) Is the 8in1 switcher on this forum somewhere? Can't say I have seen it before.


All this information is so great to know about! I have a US Major Title board that I played like crazy some ten years back but since long put it away. Found the board stored away recently. Gonna definitely do my research and hopefully put together another fun game from this board. until now I knew absolutely nothing about this Irem board. You guy's are all awesome on here thank you all for sharing this useful information.
 
Hi.

I know this is an old thread, but it also seemed to match closely with something I'm curious about, so it seemed appropriate to resurrect it.

Is there any possibility that an M72 C board could be attached to an M81 A board? Or are they physically incompatible? I ask for the cases where I am reviewing photos of various Irem games that were released on multiple A boards (M72 & M81) and the C board designation is visible but the A board is not.

I've been using this as one of my references, but there is not a picture of the M81 for me to use as a comparison with the M72.

https://www.system16.com/hardware.php?id=738

Thanks
 
Hi.

Thank you for the reply and confirmation. This will help me with purchasing an M72 set.
 
Thanks for bumping the thread, it seems the original links for the images had disappears so I updated with new images.
 
Hello I am new here and hope I selected the right place for my question:
What about the bootleg PCBs of IREM games how do they fit into the picture?
If I understood it right they played a major role in understanding the IREM boards especially the custom chips.
I just bought one of Hammerin' Harry got it for 70€ (+30€ international shipping) not exactly cheap but not bad I think for a supposedly running board.
I attached the pictures from eBay (did not receive it jet).
This board is M84 based to my understanding is that right?
I had a look to the mame ROMs of my board hharryb and hharryu (M84) the main CPU ROMs 2x 128k seem to be different so I tried to exchange this two ROMs in the ZIP file with the ones from the M84 version and run mame from command line to get past the CRC check. And surprisingly the game started (only played 1-2 min). Would that mean the bootleg runs with the original ROM set?
This is my first Arcade PCB so I just started with that. And I am sorry if I asked questions that are already answered multiple times please give me a pointer where.
I have seen pictures of a board that looks like mine but modded to run R-Type II that is actually what I want to do with this board mod it to run R-Type II ROMs.
I have seen there is a project in progress by @Hammy M84 Conversions.
How high is the chance that this conversion roms will run as well? And if not what would be need to make them work.
I am aware the layout is completely different but starting form schematics I should be able to create a PCB layout that fits to the different ROM socket location.
I found the schematics of the M72 but not for M84 or my bootleg board, does anyone have them and is willing to share?
Thank you very much.
Please ignore my bad spelling and bad grammar I am from Germany and tried to write this without the help of translation tools.
 

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Welcome to the forum @natas

What about the bootleg PCBs of IREM games how do they fit into the picture?
Bootlegs are a completely different beast all-together. I'd say they don't fit into the picture because they're in a completely different picture. Some bootlegs are near exact copies of the original, others have substantial changes, and more are somewhere in-between. Also this varies from bootleg to bootleg. Some original hardware might have 5 or 10 different bootleg boards that vary from near identical copies to being nearly completely different hardware.

I had a look to the mame ROMs of my board hharryb and hharryu (M84) the main CPU ROMs 2x 128k seem to be different so I tried to exchange this two ROMs in the ZIP file with the ones from the M84 version and run mame from command line to get past the CRC check. And surprisingly the game started (only played 1-2 min). Would that mean the bootleg runs with the original ROM set?
it's entirely possible, but you're on the right path to understanding how to make a conversion work.
I'd recommend once you have the board in hand to dump the ROMs and see if they do indeed match the bootlegs set in MAME (your board could be a completely different bootleg board) From there you can also look at the MAME driver and try to understand the hardware differences between the original and the bootleg, and try to understand what is different about the ROM data and why they modified the ROMs (see if you can identify differences in the bytes, and then flag those regions in MAME to see when that section of code is run)

I have seen pictures of a board that looks like mine but modded to run R-Type II that is actually what I want to do with this board mod it to run R-Type II ROMs.
I have seen there is a project in progress by @Hammy M84 Conversions.
Hammy is certainly the best person to answer this question :)

This thread is mostly for people trying to Identify which original Irem board they have by it's shape. I'd recommend starting a new thread to ask about the conversion, or if there's another thread that is already discussing this conversion continue this conversation there.
 
We are getting offtopic so I keep it short:
Yes, I do. (I should have searched for you on YouTube) The one-wire-mod does the magic? Are the ROMs patched as well?
If I can make it R-Type I & II (with stacked EPROMs and switch) it would be already close to perfect for me. Of course 12-in-1 would be even better.
May I contact you by PM or can we start a new topic for this specific clone board and it's possibilities? Or does such a thread already exist and I did not find it?
 
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Yes, I do. (I should have searched for you on YouTube) The one-wire-mod does the magic? Are the ROMs patched as well?
Roms n' mods :D

If I can make it R-Type I & II (with stacked EPROMs and switch)
Nope, this one does not work on here. I was going to work with @Trol on getting some more stuff working (my problem is time to burn / test roms)
Also he is waiting for the boards :D

May I contact you by PM or can we start a new topic for this specific clone board and it's possibilities? Or does such a thread already exist and I did not find it?
There is no guide, not all bootlegs are the same. when you get the board, please dump the program roms, and also fit the missing rom sockets on the top board.
Also verify the board is FULLY working before we start. (test the flipscreen dip switch!!!....)

When you are setup let me know!

I will write a guide, and anyone who has donated like you did can get a copy :)

70€ (+30€ international shipping) not exactly cheap but not bad I think for a supposedly running board.
For anyone thinking there's "PROFIT" here, i sell working/done RT2 bootlegs for £150 (got about 4 in stock now...),
So there's nothing to gain if anyone tries flipping.

For REAL M84 hardware, i'm still waiting for the original hammering harry (WORLD) set to be dumped before anything is released for that one.

-Carl
 
Roms n' mods :D


Nope, this one does not work on here. I was going to work with @Trol on getting some more stuff working (my problem is time to burn / test roms)
Also he is waiting for the boards :D


There is no guide, not all bootlegs are the same. when you get the board, please dump the program roms, and also fit the missing rom sockets on the top board.
Also verify the board is FULLY working before we start. (test the flipscreen dip switch!!!....)

When you are setup let me know!

I will write a guide, and anyone who has donated like you did can get a copy :)


For anyone thinking there's "PROFIT" here, i sell working/done RT2 bootlegs for £150 (got about 4 in stock now...),
So there's nothing to gain if anyone tries flipping.

For REAL M84 hardware, i'm still waiting for the original hammering harry (WORLD) set to be dumped before anything is released for that one.

-Carl
I will dump the EPROMs and replace them with Flash or EEPROM so it is easy for testing.
This PCB is my first Arcade board.
I prefer the bootleg over the original because it does not have custom chips and some of the week points like the breaking resistor arrays.
I was hoping it is close enough to the IREM to run the original unmodified Hammerin' Harry M84 ROMs.
I tested that on mame and it seems to be fine.
I am fascinated how this PCBs are able to produce this kind of graphics and sounds with some 74 series TTL chips and a 8MHz 8086 CPU (V30) while PCs of that time 1987-1990 just changed from EGA to VGA. And the graphics are more colorful than the Amiga graphics.
For me it is far more interesting to learn how a conversion is done than to play the game.
It is good to know you have many arcade boards and if I need something specific I will ask you first.
I do have some equipment (TL866 II, 2 channel USB scope and 16 channel USB logic analyzer, soldering equipment and Multimeter) so I am able to do some repairs and I can read schematics. But what I am missing are working reference boards for testing suspect chips and I also don't have a chiptester.
 
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Sadly, this bootleg has errors but it's about 95% ok.

For me it is far more interesting to learn how a conversion is done than to play the game

The buzz of cracking a game, or repair is better , conversions are cool as a proof of concept but are quite lame after a while if everyone does it.. it destroys history.
I tend to only do reproduction romboard hardware these days, this m84 stuff is very old work.
 
What kind errors does it have?
Actually by the name of this thread I was hoping for the information what is exactly differences between the boards, so far I found this info:
Dates are likely from copyright of the first version on the market.

M-72 (1987?) 3 PCB stack:
Main CPU: V30 (@ 8 Mhz)
MCU Intel 8751 (@ 8 MHz)
Sound CPU: Zilog Z80 (@ 3.579545 Mhz)
Sound Chips: Yamaha YM2151 (@ 3.579545 Mhz), 8-Bit R-2R DAC
Video Type raster, resolution 384×256@55,017606 Hz, CRT 15kHz, pixel clock @8 MHz
1987 Battle Chopper (World) [BCHOPPER.ZIP] / Mr. HELI no Dai-Bouken (Japan) [MRHELI.ZIP], M72-B-D (bottom) / M72-A-C (middle) / M72-C-A (top),
horizontal, 2x Joysticks 8D, 4B, MCU dumped
1987 R-Type (US) [RTYPEU.ZIP] / R-Type (Japan) [RTYPEJ.ZIP], M72-B-D (bottom) / M72-A-C (middle) / M72-ROM-C (top),
horizontal, 2x Joysticks 8D, 4B, no Protection because no MCU, no sample playback because no DAC (M72-ROM-C not M72-C-A)
1988 Image Fight (World) [IMGFIGHT.ZIP] / Image Fight (Japan) [IMGFIGHTJ.ZIP], M72-B-D (bottom) / M72-A-C (middle) / M72-C-A (top)
vertical 270°, 2x Joysticks 8D, 4B, MCU dumped
1988 Ninja Spirit (World) [NSPIRIT.ZIP]/ Saigo no Nindou (Japan) [NSPIRITJ.ZIP], M72-B-D (bottom) / M72-A-C (middle) / M72-C-A (top)
horizontal, 2x Joysticks 8D, 4B, World MCU not dumped, Japan MCU dumped
1989 Dragon Breed (World, M72) [DBREEDM72.ZIP] / Dragon Breed (Japan, M72) [DBREEDJM72.ZIP], M72-B-D (bottom) / M72-A-C (middle) / M72-C-A (top)
horizontal, 2x Joysticks 8D, 4B, World MCU not dumped, Japan MCU dumped
1989 Legend of Hero Tonma (World) [LOHT.ZIP] / Legend of Hero Tonma (Japan) [LOHTJ.ZIP], M72-B-D (bottom) / M72-A-C (middle) / M72-C-A (top)
horizontal, 2x Joysticks 8D, 4B, MCU dumped
1989 X Multiply (Japan, M72) [XMULTIPLM72.ZIP], M72-B-D (bottom) / M72-A-C (middle) / M72-C-A (top)
horizontal, 2x Joysticks 8D, 4B, different addressing PALs/memory map, MCU dumped
1990 Air Duel (World, M72) [AIRDUELM72.ZIP] / Air Duel (Japan, M72) [AIRDUELJM72.ZIP], M72-B-D (bottom) / M72-A-C (middle) / M72-C-A (top),
vertical, 2x Joysticks 8D, 4B, MCU dumped
1990 Daiku no Gensan (Japan, M72) [DKGENSANM72], M72-B-D (bottom) / M72-A-C (middle) / M72-C-A (top),
horizontal, 2x Joysticks 8D, 4B, normal M72 memory map, but IRQ vectors and sprite control as in X-Multiply, MCU not dumped
M-73 (1991?) Same as M-72? 3 PCB stack:
1991 Gallop : Armed Police Unit (Japan, M72) [GALLOPM72], horizontal, 2x Joysticks 8D, 4B, no Protection sample playback only, MCU not dumped

M-81 (1989?) 2 PCB stack:
1989 Dragon Breed (World, M81) [DBREED.ZIP], M81-A-B + M81-B-B, horizontal, 2x Joysticks 8D, 4B
1989 X Multiply (World, M81) [XMULTIPL.ZIP], M81-A-B + M81-B-B, horizontal, 2x Joysticks 8D, 4B
1990 Hammerin' Harry (World, M81) [HHARRY.ZIP], M81-A-B + M81-B-B, horizontal, 2x Joysticks 8D, 4B

M-82 (1990?) 2 PCB stack, no MCU, Z80 ROM:
Board has an extra sprite layer, rowscroll, and a larger tilemap. Tile data from both tile layers now comes
from a single set of ROMs, flip bits moved to 2nd word meaning max of 0xffff tiles.
1989 R-Type II (Japan) [RTYPE2J.ZIP?], (M82-A-A + M82-B-A? Bootleg?), horizontal, 2x Joysticks 8D, 4B
1990 Air Duel (World, M82) [AIRDUEL.ZIP], M82-A-A + M82-B-A, vertical, 2x Joysticks 8D, 4B
1990 Daiku no Gensan (Japan, M82) [DKGENSANM82.ZIP], M82-A-A + M82-B-A, horizontal, 2x Joysticks 8D, 4B
1990 Major Title (Japan) [MAJTITLEJ.ZIP?], M82-A-A + M82-B-A, horizontal, 2x Joysticks 8D, 4B, uses M82/M84 features

M-84 (1991?) 2 PCB stack, no MCU, Z80 ROM:
1989 R-Type II (World) [RTYPE2.ZIP?], M84-A-A + M84-B-A, horizontal, 2x Joysticks 8D, 4B
1990 Hammerin' Harry (US, M84) [HHARRYU.ZIP], M84-A-A + M84-C-A, horizontal, 2x Joysticks 8D, 4B
1990 Major Title (World) [MAJTITLE.ZIP?], horizontal, 2x Joysticks 8D, 4B, uses M82/M84 features
1991 Cosmic Cop (World) [COSMCCOP.ZIP], M84-D-B + M84-B-B, horizontal, 2x Joysticks 8D, 4B, V35/No IRQ controller
1991 Ken-Go (Japan) [KENGOJ.ZIP]/(World) [KENGO.ZIP]/(Set 2) [KENGOA.ZIP], M84-D-B + M84-B-B, horizontal, 2x Joysticks 8D, 4B, Encrypted, V35/No IRQ controller

M-85 (1990?) 2 PCB stack:
possibly just M84 with a modified sound section?
most Jamma inputs not connected, trackball only
1990 Pound For Pound (Japan) [POUNTFORJ.ZIP]/(World) [POUNTFORU.ZIP]/(US) [POUNTFOR.ZIP], vertical 270°, 2x Trackball 2B

All this boards seem to are specked:
CPU : V30 @ 8 MHz - Sound CPU : Z80 @ 3.579545 MHz - Sound Chip : YM2151 @ 3.579545 MHz

Code:
IRQ controller
--------------
The initialization consists of one write to port 0x40 and multiple writes
(2 or 3) to port 0x42. The first value written to 0x42 is the IRQ vector base.
Cosmic Cop and Ken-Go have a V35 CPU with its own IRQ controller built in.

Game      irqbase 0x40  0x42
----      ------- ----  ----------
rtype       0x20   17    20 0F
bchopper     "     "     "
nspirit      "     "     "
loht         "     "     "
rtype2       "     "     "
airduel      "     "     "
gallop       "     "     "
imgfight    0x20   17    20 0F 06
majtitle     "     "     "
poundfor    0x20   17    20 0F 0A
xmultipl    0x08   13    08 0F FA
dbreed       "     "     "
hharry       "     "     "
various NANAO marked customs:
KNA91H014 found on M72, M75, M81, M82, M84, M85, https://www.arcade-projects.com/thr...irem-pallet-ram-chip-repro-any-interest.6862/ (palette chip)
KNA70H015 (11) found on M72, M81, M82, M84 and M85, Replica: https://www.tindie.com/products/caiusarcade/kna70h01511-replacement/ (Video counter)
KNA70H016 (12) found on M72, M81, M82, M84 and M85, Replica: https://www.tindie.com/products/caiusarcade/kna70h01612-replacement/ (DMA controller and sprite?)
KNA71H009 (13)
KNA72H010 (14) (sprites ?)
KNA71H010 (15) (background tiles?)
KNA65005-17 found on M72, M81, M82, M84 and M85, Replica: https://www.tindie.com/products/caiusarcade/kna65005-17-replacement/ (sprite related)
KNA6034201 found on M62 and M72, Replica: https://www.tindie.com/products/caiusarcade/kna6034201-replacement/
KNA6032601 found on M57 and M62, Replica: https://www.tindie.com/products/caiusarcade/kna6032601-replacement/
KNA6032701 found on M62, M72 and M75, Replica: https://www.tindie.com/products/caiusarcade/kna6032701-replacement/
KNA6021901 found on M62 and M75, Replica: https://www.tindie.com/products/caiusarcade/kna6021901-replacement/

Custom resistor ladder reproduction for M72, M75, M92, M107 RGLD8M472J221J - RGSD10L471G https://www.jammarcade.net/vigilante-repair-log-and-irem-rgld8m472j221j-rgsd10l471g-reproduction/
 
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Your list of differences there is just the tip of the iceberg. It's not a simple job unless you know the boards inside out....
I mean, with R type 2 compared to hammering harry for example, the top boards are totally different, the main CPU is setup different(and this is critical) , Address maps changed , bigger graphics roms etc.

The mame driver has most of what we know but there's still lots of info to be added to it, I have not been able to find a mame guy who's interested in adding the irem fixes.
Although the jaleco/ nmk hardwares did get another cleanup recently with a bit of our newer info so never say never. :P
 
Your list of differences there is just the tip of the iceberg. It's not a simple job unless you know the boards inside out....
I mean, with R type 2 compared to hammering harry for example, the top boards are totally different, the main CPU is setup different(and this is critical) , Address maps changed , bigger graphics roms etc.

The mame driver has most of what we know but there's still lots of info to be added to it, I have not been able to find a mame guy who's interested in adding the irem fixes.
Although the jaleco/ nmk hardwares did get another cleanup recently with a bit of our newer info so never say never. :P
I just compiled what I found.
I can not create schematics before I get that board. Adjusting the memory map should be fairly easy I guess it is using a PAL or GAL that needs to be exchanged/reprogrammed.
For my bootleg as far as I have seen two EPROM sockets are to short so the stuck out 4 pins need to be connected if I did not miss something one on each side, one address line and 5V.
Proper schematics would be very helpful to compare things.
 
Not in m84's case, but it is for the others ;)


Yes, you will also need to fit full size sockets
Anyway address decoding is not rocket science if you understand how it works you can make things fit quite easy. And if M84 does not use a GAL what is holding me back to add one to generate the chip selects. Changing DRAM size is problematic but SRAM or EPROM is usually not that bad. A custom ROM (top) board as used for some of the multi game mods can make things a lot easier. I am not scared of unsoldering a couple of chips and put sockets in, in wich you can either plug some replacement circuit with custom PCB or the original chips.
To get back to the comparison the M8x boards should be able to run any M72 game when the requirement of the MCU is removed. But the M72 Boards are missing features that M8x use. Is that so far correct?
 
I actually have some crazy idea.
I would like to build a modular replica.
Consisting of a main board holding the V30 CPU and the 1MB RAM some BIOS and a CH376 USB-STICK controller and IO (SCART, 2x 15pin SNK, PS2 keyboard) + up to 5 ISA slots.
3 ISA-boards:
- graphic card compatible to M84.
- sound board M72 and M84 compatible with MCU.
- ROM board with enough capacity for all compatible games.
An optional PS2 keyboard can be connected and used from the BIOS.
384x256 would allow 48x32 Text characters of the size 8x8 what I guess is the tile size?
When the ROM board is used the BIOS and any additional RAM and features like PS2-keyboard, USB-Stick are disabled.
When BIOS is active it will boot into some simple OS that allows to do hardware diagnostics and to load a game from USB-Stick. Maybe port MS ROM-BASIC in a way it can work with the M84 Graphic card and add some commands to make use of the Tiles and Sprites.
 
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