This about the BOOTLEG Hardware (Not an Irem conversion)
(There are variations of this bootleg board set, more about that later)
Can't take any credit for the original conversion, I came across a thread from 2018 on arcade projects where a guy called Hammy implied he'd worked out this conversion and was doing them and selling them on. He didn't disclose the full method on that thread and I couldn't find any other info anywhere about it. I did message him about it recently to ask if he would share the secret but got no reply. So went about trying to work it out myself ...
Luckily one of the very few hits online on a search for a R-Type II Bootleg was actually a thread on here from our very own @Lurch666 over 3 years ago! who has one of these converted boards and without his help I wouldn't have been able to do this as he shared photos of his board set and the 'hacked' R-Type II prog roms that allow the game to run on this hardware. So big thanks to him !!!
So to do this conversion, firstly you'll need the R-Type II World Rom Set (rtype2) and then for some of the rom swaps you need to make a few small changes to the board ...
1) NEW PROGRAM ROMS
This Hammerin Harry uses 4 Main CPU Roms, 2x 27C512 (2&4) and 2x 27C010 (3&5) ....
R-Type II uses 4x 27C010's ... The board is set up for this you just need to extend the sockets in position 2 and 4 to allow the use of 27C010 Roms in those sockets.
Alternatively let the 2 new bigger Roms overhang the sockets and patch wire up the missing signals (pins 2 and 32)
(will insert picture of r-type II roms installed here later)
2) SWAP SPRITE ROMS & SOUND ROMS
This one is easy ... swap the 4x Hammerin Harry sprite roms for the 4x R-Type II sprite roms on the bottom pcb. Position as follows ...
Sound Roms are also just straight swaps
3) SWAP and ADD TILE ROMS
The Hammerin Harry smaller top board has 4 Tile roms installed but R-Type II needs 8 ... luckily again the space for those roms is there , you just need to add the sockets ... Install the R-Type II Tile Roms in the positions shown below right ... top to bottom .. IC64, IC63, IC66, IC65, IC57, IC56, IC51, IC50
We also need a wire mod here to supply the correct /CE signal to the 4 added Tile Roms ...
This needs to connect the LS273 output pin16 to the LS04 input pin13 marked in RED in the picture below ....
But you must isolate the LS04 pin13 from its original input or you will be feeding that inverter 2 signals on that pin and your screen will be a mess!
Easiest (and most reversible) way to do this is socket the LS04, and have pin13 out the socket with the wire soldered to it.
This modifies the ROM banking so the original four and additional four banks are selected alternately using the LS273 Q6 signal and its inverse through the LS04.
And if you've done all this correctly .. R-Type II conversion should be up and running the way it was done by Hammy back in 2018 ..
Only one small issue, and it was mentioned on the thread back in 2018, that the continue screen is broken. And it is because unfortunately this bootleg doesn’t reproduce the original M84 sprite priorities correctly. But the only place it's a problem is on the continue screen... you can see the broken screen below, every number just the mass of explosions, and continue at the top mostly not visible ...
So this is where I added my own small contribution to this conversion, to sort of finish it off ...
Rather than attempt to alter the priority hardware globally, I tried to patch only that screen - removed its explosion objects, replaced their backdrop with a 9×8 block of native colour-cycling O text tiles beneath the original number stencil, removed the broken large sprite-based CONTINUE sweep, and re-drew CONTINUE as normal text on the upper layer.
And it turned out quite well I think ....
(looks better on video you see the colours changing)
It's a slightly simpler looking version but at least it works and still kind of fits the vibe ...
So if you want to do this to your Hammerin Harry Bootleg board you just need a few sockets, the original R-Type II (M84) TILE , SPRITE & SOUND Roms
If you want the four PROG Roms (with or without the patched continue screen) just drop me a message !
Out of interest I analysed those original patched roms from 2018 and only 18 bytes were changed from the original R-Type II program. 13 of those bytes remapped two areas of memory to match where the Hammerin’ Harry bootleg hardware has them: D8000 - A8000 and C8000 - A0000, affecting the video/tile RAM routines and their startup tests. The remaining changes were three branch patches in the startup diagnostics, bypassing the tests/failure handling that would otherwise stop the game from booting on the different hardware.
Oh yeah ... @Lurch666 has a slightly different version of the bootleg board set to me and he reports his conversion is a bit jerky scrolling .... that may be down to his particular board set. But without others to compare to we don't know ... Mine plays absolutely great ... Such a hard game though
So mostly this was done by someone else a while ago but not properly documented and the program roms not publicly available, I'm not trying to take any credit here, just nice to figure it out, convert my own game to one I much prefer, patch the continue screen, and hopefully someone else can find it useful !
(There are variations of this bootleg board set, more about that later)
Can't take any credit for the original conversion, I came across a thread from 2018 on arcade projects where a guy called Hammy implied he'd worked out this conversion and was doing them and selling them on. He didn't disclose the full method on that thread and I couldn't find any other info anywhere about it. I did message him about it recently to ask if he would share the secret but got no reply. So went about trying to work it out myself ...
Luckily one of the very few hits online on a search for a R-Type II Bootleg was actually a thread on here from our very own @Lurch666 over 3 years ago! who has one of these converted boards and without his help I wouldn't have been able to do this as he shared photos of his board set and the 'hacked' R-Type II prog roms that allow the game to run on this hardware. So big thanks to him !!!
So to do this conversion, firstly you'll need the R-Type II World Rom Set (rtype2) and then for some of the rom swaps you need to make a few small changes to the board ...
1) NEW PROGRAM ROMS
This Hammerin Harry uses 4 Main CPU Roms, 2x 27C512 (2&4) and 2x 27C010 (3&5) ....
R-Type II uses 4x 27C010's ... The board is set up for this you just need to extend the sockets in position 2 and 4 to allow the use of 27C010 Roms in those sockets.
Alternatively let the 2 new bigger Roms overhang the sockets and patch wire up the missing signals (pins 2 and 32)
(will insert picture of r-type II roms installed here later)
2) SWAP SPRITE ROMS & SOUND ROMS
This one is easy ... swap the 4x Hammerin Harry sprite roms for the 4x R-Type II sprite roms on the bottom pcb. Position as follows ...
Sound Roms are also just straight swaps
3) SWAP and ADD TILE ROMS
The Hammerin Harry smaller top board has 4 Tile roms installed but R-Type II needs 8 ... luckily again the space for those roms is there , you just need to add the sockets ... Install the R-Type II Tile Roms in the positions shown below right ... top to bottom .. IC64, IC63, IC66, IC65, IC57, IC56, IC51, IC50
We also need a wire mod here to supply the correct /CE signal to the 4 added Tile Roms ...
This needs to connect the LS273 output pin16 to the LS04 input pin13 marked in RED in the picture below ....
But you must isolate the LS04 pin13 from its original input or you will be feeding that inverter 2 signals on that pin and your screen will be a mess!
Easiest (and most reversible) way to do this is socket the LS04, and have pin13 out the socket with the wire soldered to it.
This modifies the ROM banking so the original four and additional four banks are selected alternately using the LS273 Q6 signal and its inverse through the LS04.
And if you've done all this correctly .. R-Type II conversion should be up and running the way it was done by Hammy back in 2018 ..
Only one small issue, and it was mentioned on the thread back in 2018, that the continue screen is broken. And it is because unfortunately this bootleg doesn’t reproduce the original M84 sprite priorities correctly. But the only place it's a problem is on the continue screen... you can see the broken screen below, every number just the mass of explosions, and continue at the top mostly not visible ...
So this is where I added my own small contribution to this conversion, to sort of finish it off ...
Rather than attempt to alter the priority hardware globally, I tried to patch only that screen - removed its explosion objects, replaced their backdrop with a 9×8 block of native colour-cycling O text tiles beneath the original number stencil, removed the broken large sprite-based CONTINUE sweep, and re-drew CONTINUE as normal text on the upper layer.
And it turned out quite well I think ....
(looks better on video you see the colours changing)It's a slightly simpler looking version but at least it works and still kind of fits the vibe ...
So if you want to do this to your Hammerin Harry Bootleg board you just need a few sockets, the original R-Type II (M84) TILE , SPRITE & SOUND Roms
If you want the four PROG Roms (with or without the patched continue screen) just drop me a message !
Out of interest I analysed those original patched roms from 2018 and only 18 bytes were changed from the original R-Type II program. 13 of those bytes remapped two areas of memory to match where the Hammerin’ Harry bootleg hardware has them: D8000 - A8000 and C8000 - A0000, affecting the video/tile RAM routines and their startup tests. The remaining changes were three branch patches in the startup diagnostics, bypassing the tests/failure handling that would otherwise stop the game from booting on the different hardware.
Oh yeah ... @Lurch666 has a slightly different version of the bootleg board set to me and he reports his conversion is a bit jerky scrolling .... that may be down to his particular board set. But without others to compare to we don't know ... Mine plays absolutely great ... Such a hard game though
So mostly this was done by someone else a while ago but not properly documented and the program roms not publicly available, I'm not trying to take any credit here, just nice to figure it out, convert my own game to one I much prefer, patch the continue screen, and hopefully someone else can find it useful !
