Atari System 1 Multi

GadgetFreak

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Have played around with a few ideas in connection with original controls and have settled on an easy way to handle switching.
It's a different version of the mainboard roms that remember the last game booted and only advance to the next game when 1&2 player buttons are held down together. So when you change out control panels it is easy enough to change the game whatever the controls.

But as a quick point, Peter Packrat & Indiana Jones use micro-switch joysticks and Road Runner uses an analogue magnetic stick. All these 3 play exactly the same with a RR original stick or an UltraStik360. Of course PP had a stick mounted fire button but Ultimarc now has a flightstick version that includes a stick mounted button. Though I just use 2 buttons on my panel side by side for jump & fire.
MM of course had trackballs, but actually the internal code looks like it was written for a joystick as there are 2 layers of decoding for the coords.
And RB of course had a steering wheel and pedal. In my modified control I mapped the full left/right range of the stick as absolute steering position as the original control was self centering. The acceleration is mapped from center to full up mapping from stationary to full speed.

Out of these two games I would say MM is the most playable with a joystick, RB is playable but has a different feel from the original controls.GadgetFreak2018-12-01 00:27:58
 

Macro

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So can I knock together a set of roms that have PP, IJ, RR and MM using an ultimarc flight stick, but RB using proper control panel.

that way I just have 2 control panels and don't have to keep swapping the cart

although, really going for it, RB with flightstick left/right but pedal accelerator could be quite playable ... but that's a whole different hack

Macro2018-12-01 10:44:04
 

GadgetFreak

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Any combination is possible really, I can generate partial patches!
I just need to change my Rom Generator to control the options correctly. You just feed in the Mame rom sets for all the games and it spits out the required combined and patched rom set to go on my boards and the patched main board roms.
 

GadgetFreak

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Macro said:
RB with flightstick left/right but pedal accelerator could be quite playable ... but that's a whole different hack
Just for you Macro!

AS1Generator.jpg


This is a pic of the finished windows application that takes you selected game versions along with your control choice and then using the original rom images creates a set to be burnt to the roms for my AS1 Multi boards.
 

GadgetFreak

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Well I got my revised PCB's before Xmas and then instantly had issues with corrupted gfx in some games, tried several things but nothing seemed to work. So decided to put it to one side before I junked the lot!

Anyway, Xmax came and went, then the New Year......
Then I decided I had to go back to hitting that brick wall as I hate being beaten! Also Jase38 was going to call over with his Indy which needed fixing.
So went back to basics and went through everything bit by bit. Started on a Cart3 and got it working perfectly with all games. Then moved onto a Cart4 and confirmed the same code/hardware worked perfectly as well.
Next up was an original Atari Modified Road Blasters Cart3, this one has an extra TTL chip, kynar wire and a few eproms with legs hanging out. Anyway same code/hardware worked fine on this.

So then I came to a Cart 2, lots of tile/sprite corruption!
Anyway Jase38 turned up and we repaired his Indy, fortunately it was straightforward, blown mask roms, 6502, 6522, YM Dac, 2 x Slags, all socketed
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Anyway, Jase38 left the boards with me so I could use it to try out the Multi as his cart is a version 1 LSI Cart, quite similar to a Cart 2 in logic terms.
And of course I instantly had the same tile/sprite corruption. Anyway after a bit of Prom manipulation I have got PP, MM, IJ & RR to work perfectly but at the moment RB won't.
I have tried a multitude of things to no avail. None of the car sprites appear but the trees do and the biggest issue is that the left/right scrolling of the road fails completely. It's like the raster interrupt that sets the tile X scroll position is failing completely as the whole road and bottom info panel scroll left/right as one block.
At the moment I am stumped again and cannot see any reason why this is the case, of course it could be that it will never work on the older carts. But having gone over and over and over the schematics the small differences with the GFX roms / Proms / Slags should not really pose any problems...........
It's so frustrating
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I hate to think how many hours I have spent over the last 2 years on this, it must be well into the hundreds now and I'm still not finished!
 

GadgetFreak

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Ordyne said:
Is there anything stopping you making a new cart pcb all together ?
I have thought about this at various times. But the PCB size will make it expensive to produce and it would still need to have space for all the speech audio section and supporting components as well as the slags customs though it could be possible to use ColinD's repros.
 

ColinD

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I have the road scrolling issue on my Cockpit Boardset too !! - Luke says this is a power supply issue, think one of the chips in the sound section generates an interrupt on each line and it needs a funky voltage perhaps ?

Also no car sprites either , so pretty much the same fault.

If you work out a fix for this, please let me know
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If you do go down the route of a dedicated cart you could roll the 4 slags into one bigger cpld.

I have slags and the 40 pin hscroll, syngen and gpc chips all reprod in cpld's.

Cheers, Col

ColinD2019-01-10 14:57:32
 

GadgetFreak

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Thanks Colin, that made go back to the schematics again and look afresh at the carts. That's when I spotted a few extra TTL that I hadn't really paid much attention to before.
It seems that TTL, LSI & LSI Cart 2's do not have anything connected to the /INT3 (J1-31) pin on the edge connector which is how I think they are generating the mid screen scrolling.
Here is the schematic section from a Cart 3 PDF.

RBInt.jpg


I imagine you scroll issue is to do with one of these TTL's being faulty.

Of course it means that the RB on the multi will never work on anything less than a Cart 3! So I can stop looking
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ArcadeDanger

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Beautiful work you've got going there, I have two System 1 cabinets where I live, near Atari's old headquarters in Sunnyvale, CA. I've got boards/controls for MM, IJ, RR and RB. Would be interested if you ever made a multi kit available for sale. Thanks!
 

GadgetFreak

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Yes, but it will need a significant amount of passive components and will have to reproduce the sound circuit section completely along with the raster interrupt circuit. It will still end up being a significant sized board and making any mistakes with the schematics could be costly with board revisions
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I may still do it though one day!
 

bonehead

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I have one of these carts on test and it’s amazing.
I’m sure once Aaron is ready to sell as kits he will update the thread. Well worth the wait I can tell you.

STEVE
 

Ordyne

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bonehead said:
I have one of these carts on test and it’s amazing.
I’m sure once Aaron is ready to sell as kits he will update the thread. Well worth the wait I can tell you.

STEVE

That will be a test and half, there's not much Steve cannot break!
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