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plazma

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About plazma

  • Birthday 03/02/1978

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    Oulu, Finland

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  1. Still available. Already had forgotten I had a sales post also here. Luckily a member sent PM.
  2. This PCB protects ICs from ESD shocks originating from the joystick port. Designed for Commodore 64 but also works on other machines with the Atari compatible pinout.(0-5V voltage and signal ranges. +5V voltage on pin 7, GND on pin 8). Difference between version 1.0 (sold out) and 1.1 is slightly narrower slot for better fit. 4€ kit (two PCBs and four ESD chips) 5€ soldered PCBs (two PCBs with the ESD chips soldered to the PCB) Shipping: EU 2,40€ Non-EU 3,60€ Payment via Paypal. Add PayPal fee 0,50€. EU bank transfer also possible with no fee.
  3. Yes. I sell them. I have tested it with C64 250466 & 250469 motherboards only. Kit 12€. Assembled 17€. Shipping EU 2,30€. Non-EU 3,50€.
  4. Received the correct SRAM chips. Looks little better.
  5. You can use the VSP Lab program to check if your machine got the VSP bug. Let it run for few hours. The bug may appear after the chips warm up. https://csdb.dk/release/?id=120810
  6. VSP trick is used for horizontal scrolling. The VSP bug crashes machines when using sw with the VSP trick. One of the games using the VSP trick is Mayhem in Monsterland. Machines with the VSP bug may hang or have glitches when using SW with the VSP trick. With this SRAM board that bug is gone and VSP trick SW works. http://www.linusakesson.net/scene/safevsp/
  7. I made a compact PCB which replaces DRAM with SRAM and fixes the VSP bug. It fits 466 & 469 motherboards. I'll place some for sale after I receive the correct SRAM chips. I ordered wide SOIJ case by accident. It did fit the PCB anyway and I could test the protype. This should also work with 600XL. My 600XL is dead at the moment so can't test.
  8. Can the CPU be replaced with any 6502? R/W is on different pin but that would be an easy fix.
  9. I replaced the DRAM with 4464 chips which have been tested on a C64. PIA was soldered to the MB on the 800XL so I did not swap it.
  10. That memory test difference seem to be related how the self test program was started. With the command BYE you get two and half rows. Power up with OPTION-key down gives three rows in the test.
  11. Did some IC swaps between the 800XL and 600XL. The CPU seem to be dead. In the 800XL it gives mixed yellow/brown screen. Working CPU in the 600XL still gives red screen. All chips have been removed and reseated. DRAM was replaced with tested chips. BTW I ran the memory self test again a few times on the 800XL. Why does it sometimes test three complete rows of RAM and sometimes only two and half rows?
  12. I found an ATF16V8B chip from my C64 VSP bug fix circuit. I flashed it with my TL866II+ programmer with the jed file from "comment-1911484". It worked! Also tested with the chip from the 600XL and it also worked. Hint for others: the ATF16V8B chip is cheap and readily available. It is compatible with the GAL16V8 jed file!!! Make your own MMU chips OK. So this 800XL unit was easy since all hot ICs were faulty. Next I'll try to fix the 600XL. All ICs are rather cool. But now I can swap ICs from the working 800XL.
  13. I'll get that document and check it for diagnostics hints. I used a 5V 4.5A PSU I found in my garage. I measures it to give 5.15V and negligible ripple. I soldered a DIN connector to the cable.
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