Zaccaria Astro Wars arcade repair. An unusual arcade pcb..

[@ForgottenLore]

Loving your videos so far, it's nice to see some sane troubleshooting instead of mindless recapping from time to time. :)

[@iz8dwf]

LOL, I'm not a fan of substituting any part that hasn't really failed or went out of specs. If I don't understand what failed, I can't repair the fault usually.

[@rapiqui]

Thanks for sharing such an interesting repair, and especially for sharing your knowledge.

[@iz8dwf]

Glad you enjoyed it!

[@marcopantanetti4053]

Well done! Thanks for sharing Francesco, nice video.

[@iz8dwf]

Grazie Marco!

[@qu1j0t3]

Fantastic repair video! Can learn a lot from this, including the virtue of PATIENCE :)

[@iz8dwf]

Thanks for the nice comment! Well, the other Zaccaria PCBs are requiring a lot more patience so far :)

[@senilyDeluxe]

This arcade machine hardware is pretty much a beefed up version of the Interton VC4000 family hardware. Other Zaccaria machines have two or even three of the S2636 graphics chip (if you can call that graphics - ask me, I'm the Interton VC4000 homebrew guy, although it's been a while). EDIT: I'm not downrating the system, I kinda like the S2650 and I even prefer the S2636 over the S2637 which has a character generator built in, but doesn't have any of the flexibility in the sprite layer the S2636 has. Also I like Astro Wars. There is one at the arcade museum in Karlsruhe. It's hard as nails though, even with skills it's tough just to beat the first pattern.

[@iz8dwf]

Hi, yes, I'm currently working on the Galaxia PCBs that have 3 x S2636 video/audio ICs. Thanks for the information about the VC4000!

[@senilyDeluxe]

@@iz8dwf Having a member of the VC4000 family makes these machines fairly easy to test - the big chips are usually socketed on both. I have a Quasar I don't dare to fix. It's been stored in a shed together with lots of other boards, I also bought an Amidar from that stack. On the Amidar, roughly every 5th IC was bad (I had to un-hack the bootleg back to Scramble to get it to work). And there's fungus growing on the ROM labels. And Quasar uses 2708 ROMs, almost-obsolete-when-new 1 kilobit RAMs and lots of other uncommon chips. And the soundboard is missing. So far I just checked the four big Signetics. The 2650 CPU is dead, but all three 2636 PVIs are working. The cool thing about the 2636 is, although it (pretty much) only does sprites, they can be networked to not only produce more, but also have inter-chip collision detection, so if one sprite from one 2636 collides with one that's being rendered on another 2636, it still detects the collision.

[@iz8dwf]

@@senilyDeluxe The second board I've fixed is a Galaxia one, I had to re-program 3 x 2708 on it and substitute quite a lot of TTL ICs, almost half of them failed during my troubleshooting. And that board was serviced before by someone else too. Another Galaxia board requires all sockets to be changed and 2 x 2636 were also defective. Interestingly so far all TTL failed were Signetics ones.

[@iz8dwf]

@@douro20 I see, the arcadia has a 2637 instead of the 2636. However, the Zaccaria boards have lots more TTL ICs, things can go wrong in many interesting ways. There will be more repair videos about them.

[@douro20]

WinArcadia actually supports the hardware.

[@8-bit-gay]

Hi.. I need the schematics for Astro Wars. Do you have a link for the pdf? 🙏🏻

[@iz8dwf]

drive.google.com/file/d/1PLgalPgvfdxDeuroMN4TSMbWPEDdk4_p/view?usp=sharing

[@petesapwell]

Hi Frank, very interesting! I have a Space Firebird that has inverted RGB, oddly the manufacturers manual has an add on board for this with a 74LS04 to invert them to normal RGB of course it causes a loss in RGB ‘fidelity’ I might well try your analog circuit and see if it looks better (currently it’s a bit garish but needs inverting for its owner as it’s going into a Jamma cabinet

[@iz8dwf]

Hi Pete! If you have only "two" level color signals and you can use a TTL inverter before the DC-filtering capacitors and scaling (the analog RGB have 0-1V levels), then the LS04 can do the job. If you use it after the RGB is turned into analog, then it won't give a satisfactory result. You must check the schematics. The italian bootlegs of Missile Command for example had inverted video but it was actually on/off TTL on each color, so it could be inverted with an LS04 BEFORE the coupling capacitors.

[@petesapwell]

@@iz8dwf Morning Frank, I have the (original manual!) schematics and the outputs are from logic driven resistor ladders, So maybe 3-4 different levels, will take a snapshot and email it to you later. :) And nice work on Adrian’s bugged 6502, absolutely loved that :)

[@iz8dwf]

@@petesapwell Ok, I'll wait for the email! That find of Adrian was so astonishing! I wish we could have a chance to find something like that in EU! The 6502 was a big part of my "computer" education, I've got a VIC-20 a few months before my 12th birthday, 3.5kB of RAM were not so attractive for Basic, so I got the "6502 programming" book, the italian translation of course. It was the start of a new world for me.

[@douro20]

Isn't that odd for a Nintendo game?

[@jam99]

@20:28 Veroboard is so over rated. :)

[@iz8dwf]

LOL, I do use veroboard (aka perfboard) a lot actually, but I sometimes decide it's time to get rid of some pieces of old unetched PCB that I will never (lickely) going to etch anymore. I used to etch PCBs in my teenage years (well, up to 25 y.o. probably), then I gave up.

[@jam99]

@@iz8dwf Such practical, real electronics repair, re-use and fixing is great to see!