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donic

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    QLD
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    Frogger (bootleg)
    Lady Bug (bootleg)
    Pop Flamer - Jalco

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  1. Arkanoid (ROMSTAR bootleg) 22 pin edge connector (PCB marked as AB030) Fault reported: not working Parts used; Capacitors Z80 CPU YM2149 (AY-3-8910) sound chip BEI H20DB (see notes for details) My brother in the UK recently sent me a box full of stuff, mostly Commodore64 cartridges and parts plus there where some arcade boards too. I’ll bet they are faulty. My brother didn’t tell me what games these boards where, so I picked one out and removed the EPROMS to check with ROMIDENT. Turns out this one is Arkanoid bootleg – nice!! The board also has MC60705, and found out it was an MCU however my VP-280 reader was not able to open it so not sure if it was good or bad. I went searching data sheets and a schematic of the original Taito board that looks mostly similar to this one. I cleaned the board with compressed air and checked for any signs of damage, it looked in good condition. I removed and replaced the 220uf capacitors just as a precaution then checked for short circuits, all good. This board has a 22 way edge connector that seems identical to the “RomStar” version of Arkanoid. The difference being the +5V on the edge connector pin 13 &14 and ground on pin 6 & 7 on the board I had also had position for the header plug, but I prefer to just use the single connector. Easier to manage. I made a basic harness connector for DC and fed it +5v, my bench supply indicated it was consuming steady 2.5Amp. OK so far. Using the oscilloscope started probing around the crystal oscillator circuit showed plenty of normal looking signals. Probing parts of the circuit with RAM and EPROM showing activity on the address and data bus. The RGB monitor was showing a screen full of random graphics but with good horizontal stability so far I guess the timing circuits might be working OK. I went probing on the single Z80 CPU and found pretty much everything was in a floating state except CLOCK pin (6) was receiving a good looking 6mHz. RESET in (26) was bouncing Hi-Lo about every second so I started checking back through the RESET circuit. The Taito RESET schematics call out a TL7700 in the design, but on the bootleg board I have this chip is not there, however the board has provision but the space is empty and seemed to have been produced that way. I wonder what controls the RESET timer? Not sure. The LS08 pin (10) and that was held high at all time. The other input pin (9) was bouncing Hi-Lo. But the drawings show nothing connecting on that pin. Frustrating. I traced it back to LS393 pin (8) and the inputs there look OK. Tracing back further led me back to this unusual Motorola 4584 buffer again, I’ve gone around in a loop. I must have missed a branch somewhere, but then I notice the Z80 blazing hot temperature. It’s got no activity on the data or address line doing the chip is doing no work at all, strange. So I have an idea. Clip the Z80 pin 26 from the board and wire a pull-up resistor directly so to bypass the board RESET. Powering up now pin (20) shows pulses, and the CPU control lines are normal but nothing on data or address lines that are still floating and the Z80 quickly very hot very quickly. The Z80 is soldered directly onto the board, I decided to remove it by cutting off the legs and cleaning out the vias, since this was going to destroy the chip I had a spare Z80 from an old MSX computer that I could use. I soldered in a 40 -pin socket and just to be safe I powered up the board without the CPU to measure the RESET line was still bouncing. I powered off and pushed in the replacement Z80 and now Arkanoid boots up and runs. All signals look normal and everything seems to be working. Yay! Fixed! or so I thought. Until now I had not paid much attention to the input controls for Arkanoid and realised that a spinner is required, I don’t have a spinner. That sucks. I started to investigate, and it looks like the best option is to purchase one from Ultimarc. However something else was not quite right, the board would randomly boot up in screen alignment mode, I could sometimes coin-up and start the game normally. I thought it might be a stuck line and checked the dip switches and edge connector settings but these looked OK, checked the input mux IC’s and these seemed OK too. Also I wanted if the sound was working but all I got was static noise. I replaced all the capacitors in the audio circuit, but problem remained, this board needs +12V for the audio but does not need -5V I tried starting the board with DIP switch 6 “Test Mode” and noticed the DIP switches status rapidly flickering between states Low and High. I looked on the schematic the DIPS are connected to I/O on the YM2149F sound chip, this might explain why the sound was not working. However I didn’t have a spare YM2149 I went searching for information on YM2149F and read WIKI page that it’s mostly compatible with AY-3-8910, the difference being a clock mode state can be set to 50% if pin (26) is tied low, and when I checked the board that was not the case here, so I pulled the AY-3-8910 out of the Frogger sound board I was recently playing around with and pushed it in to the Arkanoid board. Now the sound and music started working. Yay. Great! The board was 100% working OK, it would coin-up, start and run the game reliably with music and sound but I had no way to actually play the game as I didn’t have a spinner input device. By complete good luck I found a solution that worked out very well. Now follows a long story I’ll try to keep short. My day job I work as an electrical engineer for a large OEM who design and produce autonomous vehicles. I was chatting with a colleague about sensor design changes, one of the superseded components an industrial encoder made by BEI, it’s got a really long part number which is H20DB-37-F5-SS-500-ABC-7272-SM16-24V-S. The datasheet caught my attention when I noticed the device would work at +5v with TTL and CMOS compatible outputs, so I checked that on my scope and behold it might just work. The diagram shows extract from the datasheet and the pins used from the sensor to the Arkanoid board. At this point I was able to play the game and was super happy the BEI sensor works perfectly as spinner controller, it’s got nice resolution (500) and the device is solid and weighted well. I highly recommend this, it’s certainly strong enough to take the abuse and has a bolt pattern that could fit under a control panel. All I need now is a head for the spinner shaft as a finishing touch but that’s for another day in the mean time Arkanoid is great fun to play, no high scores here though…
  2. Around the same time, I figured the CMOS I used for the repair in IC4 looked like an option to swap IC14 and IC3 for CMOS HC367 for the address line buffers as well. I was curious to see what would happen and even though the LS chips in place appeared to be working perfectly happy. Removing the original Fujitsu chips, the leg pins quite literally just fell off they had corroded so much, it was amazing they worked at all. It seems Fujitsu pins 4,5,11,12 with the center section cut out at the body of the package. The board works as expected with CMOS address buffers, looking at the signals on scope the characteristic are quite a bit different, voltage undershoot particularly with peak to peak measurements reaching over 6Volts at times. This is CMOS territory, Soon find out if it kills some defenseless LS chips else where in the set.
  3. Thanks Arcade King! I had a look at MadMikeAU post for the "Frog to Frogger" conversion since the board I have is a bootleg "Frog" - it's a good candidate for an upgrade :) I downloaded the .BIN files MadMikeAU modified, the instructions he wrote up are very good and the change is easy enough, for "Frogger" title and Konami My EPROM programer does not play well with older type EPROMS, it's a Wellon VP-280 that struggles with anything smaller than 27C512. Since this modification requires two 27C32 EPROMS for the conversion. I had some 28C64 EEPROM that my programmer was perfectly happy with they are 28 pin compatible with 27C64. I figured this was my best option so I removed the three 24 pin sockets for the main CPU code IC6, IC7, IC8 and fitted 28 pin sockets with some modification so it did not damage the traces underneath unused pins. The reason I did this I don't like pin overhang on sockets, it looks a bit untidy I think.. I doubled the .BIN files to suit 28C64 and programmed them for IC6 and IC8 then using trace wire under the chip connected pins 26,27,28,1,2 - that pulls up the unused address pin and links voltage to the supply pin. Powered the board up and it works looking like a legit Frogger now.
  4. Frog, a bootleg of Frogger on hardware marked KPOK-01A Problem reported: unknown state – found in a box. Missing some parts. Faulty parts replaced: 18.432 crystal oscillator IC86 – 2114 SRAM IC4 – 74LS367 The sound board was missing three EPROMS in locations 32,33,34 missing as was the AY-3-8910 sound chip at location 35 and 8255 I/O chip at location 40. All audio amplification components where missing. First I cleaned the boards with compressed air and examined for any signs of physical damage on the PCB traces and components. Sega / Gremlin published a Frogger service guide back in the day – it contains schematic drawings and troubleshooting, although some minor differences (and mistakes) the majority of component and interlinks match between this bootleg PCB and the original board set part. I measured across the DC input to check for dead shorts - I removed and replaced the two 220uf capacitors. I made a harness and hooked up my linear bench PSU and applied +5VDC, board powers up and consumes steady 3 Amps. I then set +5.2V delivery to offset voltage drop on furthest chip Using a scope, I can’t locate pulses anywhere on the board I check around the crystal oscillator and it’s flat lining. The main CPU crystal oscillator is 18.432 Mhz so assuming the crystal is dead I fit a brand new crystal however the board remains without any pulse and is stone cold dead. I double and triple check everything power related. I look on the sound board which has it’s own 4Mhz oscillator and CPU and there is a clock pulse present but the CPU is held in RESET. Back on the game logic board I start looking at the oscillator driver buffer circuit, it’s an 74LS368 at location 73 still no sign of pulses, only 5v at the supply pin – nothing else. I decide to isolate the clock circuit from everything else by removing the divider LS107 at location 72. Still no pulses. Measure the capacitors and resistors, they are OK. I vector test the LS368 on my TTL chip checker and it shows OK. I put in a new LS368 but still nothing. All that remains now is the crystal oscillator again – I don’t have another 18.432 Mhz – but I do have 19.660 Mhz, so I fit that and start seeing clock activity. I order the correct crystal and when it shows up I now have proper 6Mhz on pin 3 and inverted 6Mhz on pin 13. Hmm, two dud crystal oscillators – that sucks. I make a note to build a crystal tester at some point in the future. I connect outputs to RGB monitor. The game code is running. Attract mode works, coin up and player start the main game code appears to be running but the graphics are not right. The objects appear fragmented and broken. The tile graphics are in the wrong positions with corruption and random placement of other text on the screen. I don’t see the character frog and joystick inputs don’t seem to influence anything in game play mode. Using scope I start looking at the data and address lines of all RAM chips, the video RAM circuit – pin 13 on 2114 SRAM location 86 looks different to the others in attract mode. In game mode the pin data changes slightly but it’s measuring 1 Volt lower than other data lines I suspect a faulty chip. I try piggyback using a known good 2114 SRAM chip and see some improvement. I remove the SRAM chip off the board and replace it. There is some improvement in the graphics but it’s still not right - there is fragmentation on tiles and object character scrolling (vehicles, logs, turtles etc) is not working properly. The Sega service manual has some troubleshooting steps “Off positioning of character or when character such as frogs do not appear” seemed match the issue I was having. It suggests IC 37 and IC 49 both LS161 counters between object RAM and TTL RAM – these checked OK and IC 47 and IC 48 both LS86 driving the address pins checked OK, or so I thought. I was poking around measuring the object SRAM pins and accidentally shorted between RW and I/O4 Pins 10 and 11 on 2114 IC50. In doing this I noticed that the object graphics looked improved, however the main character frog was still missing, and the objects where still not scrolling correctly. This led me to think the problem might be with the LS367 object RAM buffers IC39,38,52 but they all checked OK. I then went looking on the object RAM control line from IC15 LS138, the inputs and outputs here looked OK. I check the three other selectors IC16, IC17, IC18 all LS138 and they looked OK. In retrospect here was an oversight on my part, some of the address lines measured 3.9V peak to peak but since it’s driven from three LS367 that fans out to many other parts of the circuit which seemed to be working I assumed probably OK with that amount of Voltage drop. Well I was ultimately wrong but I’ll tell you how I got around to knowing that in a roundabout way. At this point I started looking at the 8-bit address latch LS259 @loc 42 and found here is where the Sega schematic and this bootleg board differ in design. I went through and mapped out the differences and was able to account for all expected behaviour except the HCMA line which was being held high. I power cycled the board a few times and HCMA was kept held high in all control modes, the Sega schematic does not represent HCMA control line as a normal state high. HCMA line output from LS259 fans out to a number of places including the object RAM circuit - LS08 @ IC65 resolves into HCMP1 that goes through LS377 and ends at the second inputs of LS86 @IC47 and IC48 object to TTL RAM address bus. I had previously measured these inputs and assumed high state was normal. I figured the LS259 was at fault and so it was replaced, now the game started up in attract mode working normally. However success was short lived the object graphics began glitching again within a few minutes it was as bad as before. Damn. Since I spent some time tracking all the outputs from LS259 I now started paying closer attention to the inputs. I assumed everything looks OK except the buffered CPU address lines from three LS367 with average peak to peak signals around 3.9V A quote from the Sega troubleshooting guide page 11 section 3 “Buffer for address bus of IC3, 4, 14 especially too much fault of temperature” the three LS367 are the CPU address line buffers and on this board never feel slightly warm no matter how long the board has been powered up. Must have been a known failure mode back in the day and these are Fujitsu parts I guess at least 35 years old now. I didn’t have any spare LS367 chips but did have plenty of HC367 which are logic compatible only in CMOS. There are design rules for intermix of logic types it’s quite an interesting topic, however I went ahead and replaced IC4 with a new HC367 and the Frogger board began working properly in all modes. I played a few games and left the board running over night (with the RGB monitor off) the following day it was still working OK. So I reckon that’s fixed the main game for now, the sound board however is missing audio parts and needs attention next on my things to do list.
  5. Thanks heaps Kaizen! that sounds perfect mate - I am inner suburbs not too far away. I'll send you a PM.
  6. I've got a bootleg PCB set of Frogger - I think it's called "Frog" - it's broken and I am working my way through fixing a long list of issues to try and get it going again, anyway it's got three 2716 EPROMS missing from the sound PCB in locations 32,33,34. I managed to get my hands on some MM2716Q-5 and I have a Wellon VP-280 but it can't program them - it won't do 25 Volts. Is anyone in SE QLD or Brisbane area that can help me out with burning three 2716 EPROMs ?
  7. Ladybug. Repair - this is my work in progress. Logic board DG-01-LB Monitor vertical This a single board which has been sitting around for years gathering dust under someones house or something it measures 32cm x 23cm It seems to have a full chip complement. It has a single Z80 CPU and has total ten 2732 EPROMS ( Mistubishi M5L2732K) in two three separate bus banks. The first bank is LB1 to LB6 that holds most of the CPU code and has two 2kx8 SRAMS (6116-3). Also there are three PROMS marked MB7051 (82S123 32 bytes Signetics) I made a power harness with GND, +5vdc and +12vdc check polarity, OK , power up and looked for pulse. None what so ever, first tried to hook up ‘scope to pin 6 on Z80 – can see a what I think is the right sort of signal but I don’t really know is what I’m looking at on the ‘scope is normal. Anyway it seems to be the only thing buzzing on the board. I was lucky enough to find schematics on the ‘net so I printed them out. I noticed the crystal and checked there and on LS04 in loc. 1A – I think they look OK. I checked all the EPROM’s on my Sunshine reader EW904B and the 16 bit checksum’s check OK. I can’t test the PROMS, they have some pulses and seem to be half working. I don’t really know what I’m doing so I think I’ll swap some chips near the CPU, like the LS138 decoders in loc. 1K and 1J. Then I thought it might be ude to Z80 pin 24 WAIT being held LO so I traced it to the output of flip-flop LS74 loc. 7E there is a pulse arriving at pin 11 in the chain. I swapped this chip, same fault. I swapped the LS155 in loc. 5G same fault. I try to work out the schematics but not sure what to look for so eventually I get around to tracing the pulses from JK flip-flop at loc 7K, swapped this chip, same fault. Follow pulse to LS161 in Loc. 6F swapped this chip and some sick looking pulses arrive on the SYNC video output. I work out that this is part of the horizontal clock, I check pin outs on the LS161 and notice that the outputs on LS161 in loc 7D, 6A and 7M are all flat lining on the scope, I’ve learnt now that this is a bad thing. I swapped each chip and the SYNC pulses looked better and even the Z80 started to pump data and address lines at long last. Hook up Red Green and Blue to monitor and have got random pixels and stuff on the screen but the SYNC looks right. Eventually I get around to looking at some of the data outs on the 1kx4 SRAMS in loc. 4L look sicker that what I assume is normal. So I swap this 2114-2 chip and now I can see some properly formed sprites and I think this is attact mode. I coin up the board and the game appears to play, audio output seems normal. The screen now has a lot of horizontal jail bar effect lines. I follow back inputs from LS273 at loc 8C that appear too low they lead to the data pin 14 and 12 on 1kx4 SRAM at loc. 8G. I swapped this 2114-2 chip and screen has cleaned up and now can see some of the background characters but the map and screen are not right yet. I think this is the due to the EPROM data outputs at loc. 5A and 5C not pumping data out properly. I’m guessing I’m trying to work out a memory map for the logic to help me located the problem.
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