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tf_hh

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About tf_hh

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    Dragonstomper
  • Birthday 10/11/1970

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  • Gender
    Male
  • Location
    Germany
  • Interests
    Microelectronics, Atari 8-Bit Hardware, Atari 16-Bit Hardware, ATMEL Microprocessors

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  1. You can watch all eBay and similar platforms in whole Europe 😃 - except some few ones offered in France they all are PAL machines. There are only some minor differences in the PAL sub-system (PAL-I, PAL-B/G etc.pp.)., but these affects only when using the RF modulator. For example, if you got a german Atari 800 using PAL B/G, then you´ve no sound (but picture) using antenna input at older british television devices. The modern one detects all sub-systems of PAL as NTSC, too. Last week I saw a good looking Atari 800 with disk drive, 10 carts and many software on tape for 120 Euros in Italy...
  2. There are two "XEGS" carts with complete different PCBs inside. One uses these snaps. This carts are hard to open and most times you damage anything while try to open it. The other models use a screw in the middle like the brown carts with metal back.
  3. Not all 600XL are fully socketed! 🙂 I wouldn´t assume that this mod causes the issue. For the extension from 24 to 28 pins for the BASIC it´s only needed to put in the missing pins for the socket and change the both "hardwired" jumper/bridges right beside the PBI. Because addresslines here are affected, any mistake would prevent the computer from starting. Also, if something attached to the EPROM would be wrong, the BASIC won´t run in any way. To my conclusion would be: bad EPROM, bad memory or any defective around the RAM access. When EPROM and the RAM chips are excluded, I would change the DelayLine first.
  4. Would you offer exact this one? If the new produced ones have also these silly tabs which make open very hard without damage, there´s no interest by me. If the halves will be fasten with a screw, I would take 20 pieces minimum.
  5. As some people already mentioned here, I would think very intensive about purchasing such big parts from private people at eBay or Craigslist n the U.S. - my personal balance is 12:3 - 15 parcels overall in the last 25 years ordered from private sellers at eBay USA, only three of them reached me in a safe & sound condition. Some seller have only put the parts, power supply etc. loose in the box - without using any styrofoam, newspaper or similar to protect! No joke. Even when I PLEASE the seller to pack good before... also it´s not safe to take offers using the Pitney Bowes service, because they didn´t inspect what the customer sent (Pitney Bowes serves the "ebay international shipping program" for U.S. customers). WHEN you decide to order something, only pay using Paypal, official payment using eBay checkout. When parcel arrives you, open the box with a witness and capture the open process by video - let the witness make this video by a smartphone, that´s enough. This helps dramatically to get your money back from eBay´s buyer protection, specially when the seller did horrible bad packaging... Technically you need to change the whole CPU board (you need PAL ANTIC and GTIA chips and the PAL color clock generator on the PAL CPU PCB) or my Super Colour CPU Card (SCCC). A new system crystal is also needed. This one for PAL is very special and can only purchased from BEST Electronics or MyAtari. Purchasers of my SCCC can get the special PAL system clock crystal for a bargain. At last you can change also the operating system - but it´s not mandatory. You can use the 800 also with NTSC ROMs for O.S., some trouble only may appear when loading tapes from datasette or printing to SIO attached printers. But in real life... no problems.
  6. Hmm - I´ve done dozens of experiments with the joystick ports in the 80s. Own modem interfaces, printer interfaces and several stuff. It was the time before the internet was present and informations where rare in Europe. So a lot of tinkerer "made their own thing". IMHO the ports are very stable and rugged. When something was damaged, then issues in the circuit were the culprit, most time when plugged in while the computer was already powered on. When talking about using the joystick ports as an output. it´s mostly needed to use amplifiers. At some systems (computers) with some PIAs it worked without, at some not. When I do my stuff with the 74LS164, I also got problems. My solution was simple: This is a very simple thing I´ve made 10 years ago or so for the ABBUC magazine. It´s used to connect a standard HD44780 character display to the joystick port. Some simple BASIC and machine code samples came with. The both resistors R9 and R10 are only used for generating specified POT values which the "driver" software can use to check for the presence of this circuit. Without using the transistors I also got a lot of trouble with the 74LS164. Edit: Because two users ask me, here are the files for the public. The ATR file includes a sample ATARI-Basic and a sample 6502 assembly language to access the HD44780 display. Schematics are already included above. The PDF file (not protected) contains the article for the german ABBUC magazine, where this little project is explained. Please use Google translator or similar, thanks. Text2LCD.atr Text2LCD.pdf
  7. Yes, this was a typo - corrected! Thanks!
  8. Yes, this is possible. The 256 KByte disc buffer is mapped in 32 banks with 8 KByte each. Of course you could put 65C02 code there and let it run. The Speedy systems uses the 65C02 CPU, this is the CMOS enhanced 6502 with some new commands. Most Atari 8-Bit compilers/assemblers supports creating code for this CPU, too. Here´s the memory map: $8000-$9FFF Banked 256 KByte disc buffer, 32 banks with 8 KB each $A000-$BFFF Standard 8 KB trackbuffer as found in all Speedy versions $C000-$DFFF Dependent on firmware: SuperSpeedy copy tool or HSS copier (booted into computer) $E000-$FFFF Speedy base firmware Change of bank: Write bank-number 0 to 31 to any address between $6000 and $7FFF. The area between $4000-$5FFF is used for track display and density display (supported not by all firmware versions of the speedy). Also the beeper is accessed in this area. All addresses below $4000 are routed to the 1050 mainboard to access FDC, RIOT etc. Attention: My solution allows the usage of 32 banks (=256 KB), the genuine Super Speedy uses six SRAMs with 32 KB each giving a total of 192 KB only. Jurgen
  9. Hi all, just want to announce that I´ve made a new replica for the Atari 1050 diskdrive, it´s The Mini Super Speedy 1050! This is an updated version of my MiniSpeedy 1050 with Super-Speedy functionality. You get all the features from the well-known Mini-Speedy 1050 with the additional feature to copy whole discs in less than 40 seconds (format, write, verify)! The Super-Speedy includes a 256 KByte buffer which holds the complete single density, enhanced/medium density or double density disc read before. Because the data must not transferred through the bottleneck SIO buss, one complete double density disc will be read in approx 10 seconds or less. Once loaded into the internal memory, you can create as much copies you want. Maximum time for writing a full double density disk with format and verify is 40 seconds. The special copy tool for using the Super Speedy function will be booted with open disc lever and the 1050 set as D1: into your Atari computer. Further the computer is only used as a terminal, all read and write accesses will be done by the 1050 itself. Without booting the copy tool, the Super-Speedy acts like any other Speedy 1050, too. It has the firmware V1.7 and runs fine with NTSC, too! By default (see the red jumper) the Super-Speedy firmware is active. When the jumper is removed, the standard Mini-Speedy V1.7 firmware with HSS copier is active. I patched the HSS copier to english language. Of course it also runs fine with NTSC systems. Find the installation instructions here: http://www.van-radecke.de/MiniSpeedy/MiniSuperSpeedy1050.pdf I´ve made a little video (made with cell phone, please excuse the quality) copying one double density disc with the Super Speedy: http://www.van-radecke.de/MiniSpeedy/MiniSuperSpeedy_copy_in_action.mp4 When using NTSC, you will see the timer more increasing, the reason is the 60 Hz vertical frequency, which is used for the timer. So real time needed is approx 30-33 seconds for a full double density disc to write (format & verify), but when done with a NTSC system, it will show up to 40 seconds, but uses only 30-33 😀 Mini Super Speedy 1050 is availible in 2-3 weeks. See my linked document in the signature below for more informations! Jurgen
  10. tf_hh

    tf_hh

  11. Hi, I found a little "issue" with the 1088XEL V1.1 - only with PAL chips and crystal equipped (I think so). After building 7 pieces of the 1088XEL V1.1 for different people, I have every time the opinion, that the screen is too greenish. Look here, one example: Of course I know, effects like camera setup, color settings at your computer or mobile device is always falsifying what I want to show, but I think most people trust me to judge this behavior the right way 😀 One of 7 boards I have assembled didn´t make any right color, it´s shows totally wrong colors even when I set the color pot to the maximum. So I start to examine this issue and found out, that the maximum voltage which can be produced by the loading pump at the 1088XEL circuit is approx 6.5 volts. Some of the 7 pieces only reach 6.0 volts, one only 5.9 volts. As every hardware guy knows, the color settings depends on GTIA, CPU (which PH1 signal is used for the loading pump) and in part also ANTIC. So I try to change them with several other, best known working parts and the issue changes slightly, but never the wrong color behavior is solved. After changing several GTIAs and CPUs, I look about the differences between Mytek´s solution and the one found in the 800XL five-chip standard version. The one and only difference is the transistor Q9. Atari used the 2N3904 transistor nearly everywhere, Mytek uses the 2N2222. So I change the following transistor to a 2N3904: This fixes the behavior perfect. Now the range of voltage setting with the color pot is up to 8.5 volts, which matches my reference 800XL. I didn´t look closer into the datasheets of the transistors, but the 2N3904 works better here. Maybe it´s also my 2N2222 series I purchased, but generally all parts of the 1088XEL I have assembled work fine. @Michael: Would suggest you to mention that in the BOM. I can´t test now, if NTSC is also affected, but I think not, as most systems are build from NTSC using guys IMHO. Jurgen
  12. Not really. Of course the S version will be less hot in the Atari 800 than the standard version, but the difference is maybe 5 degrees C (never checked it for a long using period).
  13. The 7805 linear voltage regulator is availible in a 1.5 amp max. version - called 78S05. I´ve also only used this time for replacement all the years and all systems work fine
  14. Did you order them from a china seller? Maybe these are bad parts, re-labeled 1 MHz versions or whatever. I´ve ordered some 68B21 (the 2 MHz version of the 65xx PIA, it´s absolute the same like a 6520A) some months ago to have spare parts for XL/XE repairs. Due to the very cheap price I ordered 10 pieces each from two different china sellers at eBay. Unfortunately I didn´t mark them, so I don´t know which seller was good Nevermind, from one seller 9 of 10 pieces 68B21 work absolute fine for a 3-hour burn-in-test period. The other lot I got (also 10 pieces) were completely defect or run defect after a few minutes of usage.... So maybe your 68B21 is defect. Easiest way is to test it in any XL/XE. When the computer boots fine, check also both joystick ports. If everything works fine, then this PIA should work fine in the EPROM-programmer, too.
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