rigues

Hi A.J. I know, I found TIAs at Best Electronics listed at US$ 11 each. Here the KSC131 cost R$ 5.00 each, that's US$ 2.50. But the store only had five of them, old stock, and I bought two. A friend on another state (Espirito Santo) says he can find them for R$ 4.00 each (US$ 2.00), but I don't know about availability. However, when searching by the code on Google I found lots of references to the KSC131 on electronic component stores, maybe they are more readily available than we think. Kinda like happened last year, when one member on my MSX (a japanese 8-Bit computer) user's group found a clone (UM3567) for the FM synthesis chip (Yamaha YM2413) used on our MSX machines. The Yamaha chip was almost impossible to find, but would eventually turn up on small quantities at prices like US$ 30 each, minimum order of 50 pieces. The UM3567 could be found at US$ 10. The problem was acquiring them. They were being used as sound ICs on slot machines, which are illegal here in Brazil (albeit being everywhere). When I entered a store to ask for them, the manager came in, gave me a good look and said "boy, boy... why do you want these? who are you working for?". Took me some time to calm him down and convince him that I was not with the police, and just wanted to fix an old computer

russdog, thank you VERY much! The potentiometer you talked about is located between the power and B&W switches on the Brazilian Atari Polyvox 4-switch board. A quick adjustment brought the colors back, and a REALLY BIG smile to my girlfriend's face. And to think I was planning to "go hardcore" and replace every capacitor and transistor around the TIA hoping to fix the issue

Hi Folks, I'm facing a weird problem while trying to repair my girfriend's 2600, and thought someone here would be able to shed some light on the issue. It's a 4-switch Polyvox machine (from Brazil), made circa 1986. The problem is: some colours on the image are missing. You can see a good representation of the issue here: http://www.caetano.eng.br/rigues/temp/DSC04430.JPG As you can see, green is missing. At first I thought the problem was on the internal transcoding board (NTSC->PAL-M) and removed it, bringing the console back to NTSC (most modern TVs in Brazil show NTSC anyway). Seeing that it had no effect, I turned my attention to the RF module, and did an A/V mod [1] on the machine. Still no deal, so I tried the TIA. The chips are all socketed, and at first I replaced the old worn-out TIA socket with a new one. As a last resort, I spent 4 hours scouring the electronic component shops here in São Paulo looking for a new TIA. I lucked out and found a shop with few pieces of a compatible part (KSC131) in stock and bought two, but even those didn't solve the problem. Does anyone have any idea on what might be going wrong? Any parts that I should check? This console means a LOT to her, and I really want to get it back to a working condition. [1] - The A/V Mod (portuguese): http://sti.br.inter.net/elucas/artigos/Atari-AV/ Thanks for your attention!

Hi Folks, I'm facing a weird problem while trying to repair my girfriend's 2600, and thought someone here would be able to shed some light on the issue. It's a 4-switch Polyvox machine (from Brazil), made circa 1986. The problem is: some colours on the image are missing. You can see a good representation of the issue here: http://www.caetano.eng.br/rigues/temp/DSC04430.JPG As you can see, green is missing. At first I thought the problem was on the internal transcoding board (NTSC->PAL-M) and removed it, bringing the console back to NTSC (most modern TVs in Brazil show NTSC anyway). Seeing that it had no effect, I turned my attention to the RF module, and did an A/V mod [1] on the machine. Still no deal, so I tried the TIA. The chips are all socketed, and at first I replaced the old worn-out TIA socket with a new one. As a last resort, I spent 4 hours scouring the electronic component shops here in São Paulo looking for a new TIA. I lucked out and found a shop with few pieces of a compatible part (KSC131) in stock and bought two, but even those didn't solve the problem. Does anyone have any idea on what might be going wrong? Any parts that I should check? This console means a LOT to her, and I really want to get it back on a working condition. [1] - The A/V Mod (portuguese): http://sti.br.inter.net/elucas/artigos/Atari-AV/ Thanks for your attention!

Hi Folks, I'm facing a weird problem while trying to repair my girfriend's 2600, and thought someone here would be able to shed some light on the issue. It's a 4-switch Polyvox machine (from Brazil), made circa 1986. The problem is: some colours on the image are missing. You can see a good representation of the issue here: http://www.caetano.eng.br/rigues/temp/DSC04430.JPG As you can see, green is missing. At first I thought the problem was on the internal transcoding board (NTSC->PAL-M) and removed it, bringing the console back to NTSC (most modern TVs in Brazil show NTSC anyway). Seeing that it had no effect, I turned my attention to the RF module, and did an A/V mod [1] on the machine. Still no deal, so I tried the TIA. The chips are all socketed, and at first I replaced the old worn-out TIA socket with a new one. As a last resort, I spent 4 hours scouring the electronic component shops here in São Paulo looking for a new TIA. I lucked out and found a shop with few pieces of a compatible part (KSC131) in stock and bought two, but even those didn't solve the problem. Does anyone have any idea on what might be going wrong? Any parts that I should check? This console means a LOT to her, and I really want to get it back on a working condition. [1] - The A/V Mod (portuguese): http://sti.br.inter.net/elucas/artigos/Atari-AV/ Thanks for your attention!

Andrew, please keep going. I don't consider myself a good programmer, and I know NO assembly at all, but lately I've been feeling strangely attracted to anything related to the 2600, including programming. Browsing thru the other lessons, I was even able to clearly understand the source for the first kernel. That means you're on the right path! Greetings from Curitiba, Brazil!