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About Gaetznes

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    Space Invader

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  • Location
    Atlantic Canada
  • Interests
    Repair and Modifing vintage computers, and game consoles
    Working on my 85 302efi F150 Lariat
    Working on my 86 250 Honda Fourtrax

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  1. Always happy to open any of these to show they are authentic. I will be replacing the batteries as well. Would also consider trade for atari 8 bit carts, jamma and non jamma pcb's. Snes titles Super Metroid $60 Super Mario All Stars $40 Super Mario World $30 Zelda LTTP $60 Super Mario Kart $50 Wheel of fortune $5 Star Wars $10 Jeopardy-I’m keeping that N64 titles Crusin Usa $10 Gex $15 Mario kart $50 Super Mario Bros $40 Waialae Country Club $10 Conkers Bad Fur Day $110 007 golden eye $30 PS1 Discs are in excellent shape Silent Hill $80 Rivial Schools Disc One $40 Lunar Eternal Blue Compete $200 (Items are still sealed in individual packaging inside the box) Parasite Eve II $60 Xenogears $70 FF Origins $30 Civilzation II $35 FF VIII $30 PS2 .Hack G.U Vol.1 $40 with free strat guide Snes Console with SMW $120
  2. I eventually removed the Floppy Drive out of the external unit I had. It worked fine and did exactly as you said. Thanks
  3. After closure inspection, I determined that one of the previous owner had damaged several of the plcc ics. Also the 1040stf that has the modulator, was removed from the 520, as it was a FM. Swapping out the modulator between the two units didn't produce anything. But at this point I discovered the plcc issue. I decided to discontinue any additional work on the two defective units. Since then, I've dropped off the two non working units to a computer shop friend. That actually has a client with a non working 520STF on to do list. I'm hoping that something from those two can fix his. One less unit. Oh the roms (two prom set) were tested on the 1040STFM, they worked fine and were placed in the correct order. On a sad note, I learned the hard way that the medium and low res games make me sick. I ended up vomiting after 45mins of game play. After a quick search on line, well after I could actualy get up and stare at a screen. Other gamers suffer from something called Simulator Sickness. Theory is basically vertigo. Though I figure its more to do with the refresh rate. As some of the games were simple like battleship. Either way, i'm disappointed as I was fine while testing it for several hours on several days and playing it in High res. The theory would explain why I can't play first or third person shooters. I've since found a friend to give it a nice home. Hes having a blast with it.
  4. To the SM124, im using the monitor connector. I wasn't originally aware of the no composite without a rf modulator. So i had actually made a test rig for a rca phono jack to the tv. using that 13 pinout online. so that explain that i guess.
  5. I have re-seated all the dip ic's, and none of the plcc's. I place to burn a new set of the rainbow tos eproms tomorrow. Also thanks for the composite / rf modulator info. Since writing this earlier, I noticed on the 520 that a chip is piggy backing on another. You can see on the top left of the picture, of the mobo, U1 7405 ic. Ill remove that tomorrow.
  6. I'm a Atari ST / 68000 / 16 bit computer virgin. I have no experience with the 68000 based hardware beyond some minor arcade repair. Though, that was mainly eprom related. So I picked up the three computers. Which i'm trying to identify going by the pcb. I've recaped and tested one of the psu's and have used this one to do all my testing. After checking voltage. I'm looking for advice, or at the least direction to sources to do my own research. Can't seem to google successfully "Troubleshooting" to the same success as say a Atari 8bit computer, Commodore 64 or Nintendo products. Computers on hand 1. 520 STF / c070789-001 rev d 2. 1040 STF / C070523-001 rev d 3. 1040 ST / c103225 rev.1 or is this a 1040 STFM? I ask because that was the case it was in. Status All tested on the monochrome Hi Res Atari Monitor SM124 and Composite &/or RF on a Modern LCD. Green light in bottom left turns on for each of them. Each of them had psu and floppy drives inside. Pictures below. 1. 520 STF / c070789-001 rev d / Total black screen on Monochrome. No image on LCD. No audio when keys are pressed. 68000 cpu had significant corrosion, so I replaced it. No Change. 2. 1040 STF / C070523-001 rev d / Distorted image on Monochrome Monitor, nothing on LCD, Audible sound when key is pressed. Image changes slightly about a min after turning on the computer. Audible sound is no longer available when pressing key. Image reminds me of a RGB without sync. 3. 1040 STFM / c103225 rev.1 / Working, Tested on Hi Res Atari Monitor and Composite on a Modern LCD. Giving a extremely clear image. RF works on channel 2, but their is significant audio and visual static. I can't rf tune it in on this lcd. As recommendations have noted, that i've read. Images 2. 1040 STF / C070523-001 rev d When first turned on. Sorta looks like the menu is skewed across the top. 2. 1040 STF / C070523-001 rev d, Min or so after turning on. Its as if it took that long for the cursor is now skewed or infinitly mirrored across the screen. 2. 1040 STF / C070523-001 rev d, PCB 1. 520 STF / c070789-001 rev d 3. 1040 ST / c103225 rev.1 3. 1040 ST / c103225 rev.1 Shown working
  7. Ok to answer the above questions. The ram is a quantity of 8 (4164) Voltage with a load on it, is 5.08v. That is also the plan, well the mmu was a consideration. I hadn't considered the pia chip. Good thing I have spares to follow that recommendation.
  8. Back Story Last month I received this in trade. It was known dead, or at least it was a pure red screen of death. Previous owner plugged a C64 psu into it. I replaced the ram, which got me to the black screen of death. After which I replaced the masked os with a eprom. Everything seemed to work at the time. Though I had not tested it with a cartridge. I only performed a few simple commands on the screen. After It booted into basic with no problem. Current Status After attempting to play a cartridge game. I received a multitude of different results. In rare cases Blue Max did appear on screen. however it has not worked after hitting the reset button. Other results range from black screen, frozen at the blue screen (Ready not showing up), a bunch of random characters appearing on the blue screen, and varied result from the self test. Self test prior to inserting cartridge will state both roms are good. After inserting cart and after removal of cart. I will get a black screen, if the game doesn't boot. I then have to use the option key to boot into self test. At this point both roms are red. I have tried this with two alternative OS and Basic masked roms and one burned OS on a eprom. The masked roms are out of known working 800xl's. All having the same effect. After forcing the self test, I can generally get back to some other resulting screen. That i've stated above they generally have been frozen. I can only get back to the normal basic screen with ready if I unplug and turn off and on the system several times over a min or leave it sitting for several mins. Each hard restart is followed by at least 10-20 second, prior to another attempt. Other points of note I've followed the instructions for he Black Screen post by brensk Tested all the caps, and they are good PSU 5.12vdc Once a shipment of sockets arrive, i'm considering swapping out the the MMU from one of my 800xl I don't own an oscilloscope Does anyone have any advice ? Plus this screen came up once.
  9. You are correct, my experience with working with Atari 8bit is extremely limited. I've had to do a far amount of playing around and finding the proper roms with the proper extensions. If you get a chance to read my blog, you will see extensive human error, that leads me to the understanding the distinction between the types of extensions. On a very very basic level. I do appreciate your explanation extensively. As my primary experience with games has been focused on fixing old arcades and Atari 5200, through to the era of Genesis and snes. Building rom hack or import games. Actually working with computers requiring os, basic kernels etc is very new to me. Thanks again
  10. I have been watching youtube videos on the U1MB. That is very amazing. Lost for words on how many features exist on this upgrade.
  11. That is awesome. Are you limited to four 8KB games? Does a feature exist that allows two 16KB, or one 32KB game?
  12. Long story short. I saw a post about bank swapping the basic and a game on the 1200xl. This made me think about my xegs that I have in my repair pile. That has Missile Command internally installed on the system. So through a series of experimentation, revelations, leading me to eventually pulling out the hex editor. I determined what is partially stated in some of the references I have linked below. The C101687 rom is a concatenated file containing in this order: Missile Command 8KB, RevC Basic 8KB and Rev4 OS 16KB. The xegs C101687 ic is Jedec compatible, meaning I can use a 27c256 eprom (32KB / 32,768 bytes). The concatenated file must be that size, not a byte less or more. So the goal is to change the game. Doing limited testing, I tried multiple different extensions, xex .rom etc. The .rom extension was the only one that gave me limited success. Limited, because not every 8KB game I eventually tested worked. I used a tms27c256 eprom, Hxd as my hex editor, which also works for file comparing and concatenating the multiple files on hand. Some days Command Prompt is just not fun to use. lol. End result is I was able to concatenate my own working file containing Missile Command, RevC Basic and Rev4 OS. Later on, I did the same with Qix, RevC Basic and Rev4 OS. Below are all the references I used. In addition to my own log. That contains every assumption and conclusion made during my experimenting. Whether it was right or wrong, I left it it in my log. Hopefully others can learn from it. Picture below references. References My Mod and repair blog including this : https://www.gatesgames.ca/february-2018.html Rom sources http://www.atarimania.com/ Basic info http://www.digitpress.com/eastereggs/a48ataribasic.htm OS/Basic rom source http://atari.vjetnam.cz/index.php?frame=roms OS Info http://www.ataripreservation.org/websites/freddy.offenga/osroms.txt OS Info https://www.wudsn.com/productions/atari800/atariromchecker/help/AtariROMChecker.html IC identification https://www.atarimax.com/jindroush.atari.org/achip.html Post that triggered my experimentation http://atariage.com/forums/topic/147677-questions-about-1200xl-mods/?&p=1875799&hl=rom+socket&fromsearch=1&do=findComment&comment=1875799
  13. So I caved and de-soldered the TMS9928a out of my personal console. As well, I tested the 74ls04 logic ic. Current developments 1.Tested the 74ls04. Result: Ic tested working 2.Tested my now pulled TMS9928a in the working console. Result: Happily it still works as photographed below. Though there is graphic glitches in the b/w console, not pictured. I'll have to clean the pins, to see if I can resolve that. If not I may need to check the continuity of each pin in the socket to its destination. On the b/w console. 3. Second TMS9928a Results in working personal console: Pictured below. Blue in color, a negative image cross hatch?. I'll have to investigate this. Results in B/W console. I still have clean Colecovision Logo, game play, etc. 4. Third TMS9928a no longer will work in the b/w console nor did it ever work in my personal. To summarize. I'm going to order a replacement tms9928a, as i'm not content on having this is the only one on hand. I need to investigate the negative blue hatch pattern. See if anyone else has had this problem. A moments ago, I found this http://www.colecovisionzone.com/page/coleco%20industries/tech.html , it's a service manual. With troubleshooting. Though I don't own an oscilloscope, sigh. Even with out a scope. I hope with that and a set of schematics, to narrow it down. Either to another ic, transistor or what ever in the rf unit. Even if it means I start swapping more parts. Extremely rough way of doing it, but hey, at least i'm learning.
  14. I'm using a Commodore 1702 monitor. Which I use when I do these types of composite mods. Fits nice on the test bench. So that rules out a potential tuner issues, I assume. Since posting, I convinced myself to open my personal colecovision. Which I composited modded the same way I did this one. I only swapped out the crystal. Sadly this did not change anything in regards to the white and black screen. I tested my machine before and after removing and re-soldering the crystal. It has color on my commodore 1702. I avoid switch boxes as much as I can, and haven't been used at any point during the testing. I'm at the point, where I'm not sure what else to check. Taking into consideration the TMS9928a may still be the issue. Additionally, I have not looked into the rf circuit, and what those two ic's do if anything, in regards to color. I have already talked to the owner about the issue and he has already picked up another donor system. So I hope to get back to this as soon as I have it. That or i'm going to get bored and risk my personal coleco and remove the TMS9928a. Then I'll be able to eliminate or determine if the TMS9928a is in fact the issue. Console5 has a note on the page I referenced in post 1. That I missed earlier. Its not TI, but I do have spare 74ls04 logic laying around. It wont hurt to try. Wrong frequency 3.579 Mhz clock is the wrong frequency. If U22 is a Texas Instruments IC, replace it.
  15. A friend dropped off a Colecovision that had known issues. As the title suggest, the video is B/W. Which I have not dealt with before. After hooking it up on a know working and tested power supply. I began my work. Normal things like testing voltage a different key points at and after the switch. All is well. What I have done so far. 1. Installed composite mod test rig, in attempt that this may bypass the issue. Result: No Change, Same b/w issue as on the rf line, using a F connector. 2. Replaced the TMS9928a from another colecovision and had socketed that ic on the mobo. Though this TMS9928a came from the mobo parts pile. All the traces had lifted. So its unknown if it was fully working or not. Result: No change. 3. Replaced, the top half of the RF unit. Again coming from the same mobo as the TMS9928a. Result: No Change. 4. Replaced all the aluminium electrolytic capacitors on the mobo. Result: B/W image is sharper and cleaner. 5. Tested Both Crystals (One from the mobo i'm trying to repair, and the one from the parts mobo). Reference sources say I should have 7.15909Mhz at the crystal, and 3.579Mhz on pin 6 of J4. Result: Both did not give the proper reading and were in fact fluctuating or blanking out. Tested at the crystal. Currently waiting on an order of replacement Crystals. Will update as progress is made. Notes: Both revisions of the colecovision rf unit have a coil where a trim pot would be. That would be normally recommended to adjust for rf adjustment. As suggested by console5 Inferring some of my information based on info derived from http://www.kernelcrash.com/blog/recreating-the-colecovision/2016/01/27/ and https://console5.com/wiki/Colecovision#Capacitor_List
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