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About Levas

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  1. I am crazy... I always wanted to buy 1200XL, but they are available in USA. I live in EU. So, transatlantic shipping, import taxes. I bought one on ebay and DHL.DE lost it. So I bought second one. Then, first one returned to sender and I payed shipping cost again... and now I have two 1200XL. And yes, I am crazy. Here is my atari stuff: http://www.pumidas.com/kolekcija/tag/atari/ And other computers are too: http://www.pumidas.com/kolekcija/
  2. My guess was based on 1200XL schematic available in this forum. And, yes, I was using equations from 800XL MMU source listing. Version without BE (basic enable) is stable. Maybe original MMU PAL(?) chip has build in pull-up. Maybe there was plan to build BASIC in 1200XL, but due to hurry it was discarded. I've lost PAL->GAL fuse conversion program. And I don't have any GAL software. Maybe someone could convert fuse maps to GAL version, as there are much more available GAL programmers compared to PAL/PALCE. Look, what nice RAM chips my 1200XL have...
  3. I am playing with 1200XL MMU. I am just guessing the equations inside based on 800 MMU. Original chip is C080809, replacement- PALCE16V8H. Attached files are source code (equations) and compiled JEDEC file for PALCE chip. Tested with original Basic cartridge CXL4002, Pac-man CXL4022, Basketball CXL4004, without cartridge. There is problem- either my 1200 is with some problems, or there is need for pull-up on pin 18 of the MMU. It is BE and in schematic it is floating? It is possible to disable this pin in equations... but why it is in the schematics? Version without BE is "1201". And "new" PALCE chip is so cold, compared to original. AT1200.JED AT1200.PDS AT1201.JED AT1201.PDS
  4. As far, I don't find any problems in my PCB. Maybe anyone will build it and test with various hardware. And another present for Atari community- free 3D print (.stl) files for Atario SIO connector (cable side) are in my 3d pages: http://www.vabolis.lt/3d-failai/ Metal parts are from cheap connectors from China. Same as used in PC FAN connector.
  5. For testing, I modified MMU (PAL, PALCE or GAL) equations to use the same ROM chip for OS and BASIC. Basic now works, but I have a question- in the original atari, "option" key disables basic. In the original 1088XEL there is no basic at all- MMU pin is floating and everything is done with U1MB. In my version, Option key is not disabling basic!. Also, I can not start tape loading with the "START" key. But, if I connect GTIA's START or OPTION pins to ground, the computer starts tape play and/or diag properly. The problem is with TK-II PIC software. These keys are working fine in games or OS diagnostics. I can see that OPTION and START lines go low to late on boot. Maybe there is a special key press to enable this boot option from the PS2 keyboard? New permanent page (permalink) for this project in English language: http://www.savel.org/atari-1088xel-smd/
  6. So, there is V1.0 and it must be 1.01 because of very stupid error (do not trust chip package library from internet). Also, because I do not like how the power button behaves. It works without any patch wire. It works from cartridges. It works from USB (disk emulator- with hardware or no flow control). The only addition to start it in "stock mode" - mount ROM in riser. Must work with "U1MB"- just remove ROM board and stock MMU (the connector is hidden under MMU, in original location). If you have an "UAV"- do not populate the stock video part. Untested with "fancy hardware" - I don't have any. It is working from any (6V - 19V) PSU (about 3.5W in "stock" mode). I think it is possible to connect an SD card as a disk drive (no software written, but there are mount pins for it or any other SPI and I2C device). Free PCBs are available (you pay shipping and handling from the EU). Documentation T.B.D.
  7. New firmware for USB-SIO, now with hardware flow control (RI and DSR). For CTS flow control write letters to Microsoft or directly to Bill G. http://www.vabolis.lt/2021/04/17/arm21-stm32-usb-cdc-ir-hardware-handshake/#comments
  8. It is very interesting, because "google translate" used "bishop" here... The only connection to bishop is sound of "biški". Word "biški" means "small amount" , and "fog" is real word. It is not directly translatable idiom (like "rats in the attic" , "lazy bone" or "running around the bushes"). In current sentence- "I wrote lots of words, but the idea is not clear". And the "shit those authors" in real means "those authors are tiny peaces of shit (like shit of rabbit)" - Idea is that all authors in internet are copy-paste same example project and every one is writing that "flow control is useless in modern USB communication". But I am not very angry- so called them "tiny shit". I love to use strange words in my blog, also, sometime speak weird- using ancient form of words. Returning to Atari. New PCB (V1.0) arriving on Tuesday. I will populate it in this week and post the results. Don't worry, all files will be free and I will write all documentation in English language. I am in hurry because in summer I live in summer house and I am not doing any serious electronics at that time. Also, new EU law about taxation of small parcels will be active in month or two. I am not against taxes, but our government made it impossible to pay taxes as only "special trained person with license to fill custom declaration" can do it. Currently it is 30EUR for paperwork , 20% tax from everything (PCB, shipping, handling and ... paperwork). We are smart people and I think in few months someone will invent virtual address in other country to avoid theses taxes. Like aliexpress is sending items from some EU countries...
  9. Source code and compiled binaries for onboard USB-serial adapter. Still not working with flow control. I don't know if it is firmware or windows generic serial driver problems. Not direct link, but link to my web pages. Scroll down for download. http://www.vabolis.lt/2021/04/17/arm21-stm32-usb-cdc-ir-hardware-handshake/ (lots of old man's growling in the post)
  10. What is max size of SIO transfer in bytes? 256? I need for USB-SIO firmware optimization. Current schematics attached. 1088XEL.sch.pdf
  11. Status Report: onboard USB-SIO adapter works (still only without flow control and not all disk images are working). I know nothing about SIO, so maybe my interpretation of flow control is nonsense. Found PCB bug again- now it is mine, with STM32 lines. Nothing fatal. Now running some demos.
  12. My design is 2 layers only , €26.58 for 5 boards. If it was 4 layers... I never would order it.
  13. I am not blaming anyone, only myself. I cut traces and put 3 Kynar wires. But my one of the Atari Chips is damaged (not by this error)- this error only causes some sprites in the wrong positions. I disassembled another Atari 130 with 64K and I have a working chipset. So, I am testing it again. I soldered the STM32 chip and I can see the Atari as Atari in the Windows device manager (no, it is only a COM port). Very pity, but my USB is weak to power the whole computer. I can play cartridge games, no SIO at this time. In photo, MMU is replaced with Altera CPLD to test some configurations- I want OS and BASIC in the same chip with minimal changes and full backward compatibility with original. Thinking about 128K RAM (like in the stock). As CPLD is more sensitive, it detects one forgotten pull-up. Also- published MMU PAL/GAL source code is interesting I am thinking about removing LM2596 from my new board. I prefer pure China chips (FR9888, MP1482) - they are smaller, more efficient and very available (tons for 1$ in Ali or salvaged from PCIe risers after ETH madness).
  14. I found error! Error was in schematics I received. Someone, who prepared Eagle schematics made very stupid error. And I was too stupid to notice. All PCB are scrap, unless someone is in love with Kynar wires. Some other pedantic error detected, but nothing fatal. See GTIA chip data bus.
  15. Currently my design is universal- just one jumper ant it is 5V, no jumper- it is "HV". Same with MMU. The only incompatibility is audio connector. I don't know about "original ROM". My PCB is only 2 layers and "wide" traces. So it is quite overcrowded. Currently I must pause PCB modification- I think one of my Atari chips is damaged- I can not find probem. So some software is running quite bad (too fast). Until I solve this problem, I can not modify board- maybe there is some error on it or maybe some logic chip is slow/bad- I used de soldered ones. These crappy screenshots are from "original" 1088XEL, mine version is even worse. Anybody knows the problem?
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