Recent Posts

I'm resurrecting my Berzerk Resurrection thread.
yeah, this went nowhere for a long time.
Mostly because i really didn't have a spot to work and had to many other things to do.

currently working on the power board.

just picked up an actual Williams crt monitor from someone with a converted berzerk cab.
it needs work as it only has a white horizontal line in the middle.
research says needs caps.

the very nice gentleman who sold it to me also found all the original paperwork that came with Berzerk so I have that now also.
manuals, schematics for boards and monitor, instruction cards, warranty card ect.
stuff i can find online but it's just cool to have the originals.

it was funny because i was traveling out of town over the weekend and happened to be looking up routes in google maps and it popped up on FB marketplace in a place sort of on the way out of my set range so i probably would of never seen it.

(they are watching!)

this will still take a while to work my way through the board repairs but i've collected some good links on past restores and will link those so credit is given.

Well, did you get it working? It's been years :-)

no.
i did start cleaning the boards a few yrs ago though.
lol.

i have a back log of things i need to fix and no place to really fix them right now.
hoping to finish making the basement useful for electronic repair this winter.

Looking at that code I bet you could 'hack' mame to connect up the original pedal if you really wanted to.

Well . . . a C++ code monkey probably could do that, but I've only evolved to the level of code paramecium.      

Found some more relevant code in turbo.cpp.

Lines 662-669 define input port "IN0", line 663 shows that port bit 0x03 relates to the pedal.

Code: [Select]

static INPUT_PORTS_START( turbo )
PORT_START("IN0") // IN0
PORT_BIT( 0x03, IP_ACTIVE_HIGH, IPT_CUSTOM ) PORT_CUSTOM_MEMBER(turbo_base_state, pedal_r)
PORT_BIT( 0x04, IP_ACTIVE_HIGH, IPT_BUTTON3 ) PORT_NAME("Gear Shift") PORT_TOGGLE

Lines 565-582 show the program/address(?) map, line 580 maps port "IN0".

Code: [Select]

void turbo_state::prg_map(address_map &map)
{
map(0x0000, 0x5fff).rom();
map(0xa000, 0xa0ff).mirror(0x0700).rw(FUNC(turbo_state::spriteram_r), FUNC(turbo_state::spriteram_w));
map(0xa800, 0xa807).mirror(0x07f8).w("outlatch", FUNC(ls259_device::write_d0));
map(0xb000, 0xb3ff).mirror(0x0400).ram().share(m_sprite_position);
map(0xb800, 0xbfff).w(FUNC(turbo_state::analog_reset_w));
map(0xe000, 0xe7ff).ram().w(FUNC(turbo_state::videoram_w)).share(m_videoram);
map(0xe800, 0xefff).w(FUNC(turbo_state::collision_clear_w));
map(0xf000, 0xf7ff).ram();
map(0xf800, 0xf803).mirror(0x00fc).rw(m_i8255[0], FUNC(i8255_device::read), FUNC(i8255_device::write));
map(0xf900, 0xf903).mirror(0x00fc).rw(m_i8255[1], FUNC(i8255_device::read), FUNC(i8255_device::write));
map(0xfa00, 0xfa03).mirror(0x00fc).rw(m_i8255[2], FUNC(i8255_device::read), FUNC(i8255_device::write));
map(0xfb00, 0xfb03).mirror(0x00fc).rw(m_i8255[3], FUNC(i8255_device::read), FUNC(i8255_device::write));
map(0xfc00, 0xfc01).mirror(0x00fe).rw("i8279", FUNC(i8279_device::read), FUNC(i8279_device::write));
map(0xfd00, 0xfdff).portr("IN0");
map(0xfe00, 0xfeff).r(FUNC(turbo_state::collision_r));
}

There are also three references to the pedal in turbo.h.
https://github.com/mamedev/mame/blob/master/src/mame/sega/turbo.h
Line 41

Code: [Select]

, m_pedal(*this, "PEDAL")

Line 47

Code: [Select]

ioport_value pedal_r();

Line 68

Code: [Select]

optional_ioport m_pedal;

. . . and that's about as far as I can take it.

No idea how to change the MAME source code from a potentiometer input to the two opto inputs or how to add a "Machine Configuration" menu item to select between a potentiometer pedal and the original optical pedal.   
- There might be a clue on how to do the Machine Configuration part in the 720 source code since IIRC MAME can be configured to use either a spinner or the original controller.


Scott

ooooooh!

lemme know. I'm dying to build another CRT based cab eventually.   I think I want in.

I'm pretty sure creating them in a hobby instance and splitting up the money at *ahem* cost *ahem* would be fine.  You just can't go start selling them retail.

I wonder what mame would do if you had that type of pedal and wanted to connect it up... Might have a look at the mame source to find out if its possible.

First glance looks promising . . .
https://github.com/mamedev/mame/blob/master/src/mame/sega/turbo.cpp
Lines 443-448

Code: [Select]

ioport_value turbo_base_state::pedal_r()
{
// inverted 2-bit Gray code from a pair of optos in mechanical pedal
uint8_t pedal = m_pedal->read();
return (pedal >> 6) ^ (pedal >> 7) ^ 0x03;
}
Lines 739-740

Code: [Select]

PORT_START("PEDAL")
PORT_BIT( 0xff, 0, IPT_PEDAL ) PORT_SENSITIVITY(100) PORT_KEYDELTA(20)

. . . then I ran it in MAME 0.262.  There's no "Machine Configuration" menu so it doesn't look like there's currently any way to use the original pedal with MAME.

The good news is that you can clearly see the four different speed settings in low gear as you adjust the pedal potentiometer.   


Scott

Nice find Scott, cheers! Looking at that code I bet you could 'hack' mame to connect up the original pedal if you really wanted to. Anyways, looking forward to trying turbo out with my pedal potentiometer later

I wonder what mame would do if you had that type of pedal and wanted to connect it up... Might have a look at the mame source to find out if its possible.

First glance looks promising . . .
https://github.com/mamedev/mame/blob/master/src/mame/sega/turbo.cpp
Lines 443-448

Code: [Select]

ioport_value turbo_base_state::pedal_r()
{
// inverted 2-bit Gray code from a pair of optos in mechanical pedal
uint8_t pedal = m_pedal->read();
return (pedal >> 6) ^ (pedal >> 7) ^ 0x03;
}
Lines 739-740

Code: [Select]

PORT_START("PEDAL")
PORT_BIT( 0xff, 0, IPT_PEDAL ) PORT_SENSITIVITY(100) PORT_KEYDELTA(20)

. . . then I ran it in MAME 0.262.  There's no "Machine Configuration" menu so it doesn't look like there's currently any way to use the original pedal with MAME.

The good news is that you can clearly see the four different speed settings in low gear as you adjust the pedal potentiometer.   


Scott

Sega's   "TURBO"   also used the same optical pedal system.   (I used to own one... but sadly, had to sell it)

 Another Arcade Oddity, was TX-1..  which used optical-wheel encoders (spinners), for its Gas and Brake pedals

I didn't know that about Turbo, thanks! I wonder what mame would do if you had that type of pedal and wanted to connect it up... Might have a look at the mame source to find out if its possible. It would be good if I could see how Turbo handles the 4 pedal positions when it comes to trying to match the speed of the opponent cars. There is a chance Turbo's gameplay was slightly modelled on Monaco GP (Both Sega and both using the same pedal). I shall investigate!

@xfassa - If you're reading this, hopefully in the next debug package I'm putting together, I'm shall try and simulate the 2 optics with your analog pedal. Currently, when you hold the gas pedal in a specific position, the car will either accelerate or decelerate to a specific speed at a rate determined by a single acceleration curve. I plan to make it so that there will be 4 acceleration curves that will come into effect depending on pedal position (1st between 0%-25%, 2nd 25%-50%, 3rd 50%-75%, 4th 75%-100%). Hopefully, the pedal will feel more responsive.

Hi guys,

I've had a talk with NanotechGaming, creator of the Optigun/USB2Gun board. They have agreed to share the gerber files for the board with an open source license. I would have loved to order a bunch and start offering it on this forum but the license is strictly for non commercial use. Any one of you can take these files and use them to order and assemble your own copy on sites like PCBWay.com.

I feel like a lot of development when it comes to lightguns as been focused on getting light guns to work on non-CRTs... it's kind of ridiculous people with gun cabs have even started ripping out their CRTs just so they can get it to work..
I hope with this development we'll see more original lightgun cabs.

Anyway you can find the files here:

https://commondatastorage.googleapis.com/ultracade/990-usb2gun-UCT-00.zip

I'll add some mirrors later on.

Cheers and have a good one,
shanki

sorry, i'll try to explain a little better.

in an SMPS supply, you take AC and turn it to DC. this DC voltage is B+ then you take the B+ and pulse it 10,000 times a second through a transformer and create all the voltages (190v 20v 12v 6v etc.)

but quite often in older monitors, you'd take AC, turn it to DC... then run it through a linear regulator module to create "B+" that you then use to drive the flyback and the horizontal youke winding... then also resistors and crap to tune the voltage down for the various other circuits.

so the nomenclature of "B+" is used for a couple different kinds of voltages.

in the case of the nt500, with an SMPS... it's technically named "B+" is created with a feedback loop to a control IC (IC501) it's peak is about 392VDC this is the B+ used to be pulsed through the transformer. the R501 adjustment allows more or less voltage through to the sense pin of the control IC to raise or lower this voltage.

while technically not "B+" the main high voltage (HV+) of 140VDC used to drive the flyback (and adjusted by R601) which would normally be "B+" in other older monitors.

so in a nutshell typically, the high voltage DC side voltage is just normally called B+

generally if I say B+, i'm usually referring to the high voltage used to drive the flyback and/or possibly the horizontal deflection yoke winding if it doesn't have it's own supply (like the WG 9200/9400 does). (sorry, it does share a supply, but each has its own drive is what i meant by that.)

in any case ramble ramble ramble.

the HV and B+ in this case, very likely don't need to be messed with. quite often the spec on B+ is something super dumb like maybe... 147vdc +/- 12vdc...  so honestly it could be anywhere from 135 to 159 volts and still be fine. hell i've read specs saying B+ should be like 113 and i measure it and it's 145... and then turning it down makes it collapse and die. so take any stats you see with a grain of salt, since really...much like cooking... it should be done by feel. if it feels okay... it's okay. maybe it's just cause i'm an old grey beard.

i'm going to bed now, i feel old.

Cut a bunch of the panels, need to be cleaned up a bit. Double check square and width, sand. Gotta make sure I take an 1/8 off the back panels so I don’t scuff everything removing them, don’t ask how I know this  Went a Frankenstein route and made 5 panels for the back, they won’t be seen much and 2/5 will be glued in.

Sweet, too bad Illinois is like 22 hrs away lol. Looks like nice work man.