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rdemming

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Posts posted by rdemming

  1. Posted

    I think it could be done. According to my early revision schematics the 520ST has 16 256Kbit chips while the 1040ST has 32 256Kbit chips.

    But I supose the 520ST does not have space for those chips on the motherboard.

    You could try to piggyback the new ram chips on top of the old ram chips with the exception of the !CAS & !RAS signal pins. These should be connected on the MMU pin 18 (!RAS1), pin 21 (!CAS1L) for the first 8 chips and pin 22(!CAS1H) for the second 8 chips.

     

    On my 520ST schematics, the MMU is U15. The first 8 ram chips (data bits 0 to 7) are U16, U17, U18, U24, U25, U28, U29, U30. The second 8 ram chips (data bits 8 to 15) are U32, U33, U34, U38, U42, U43, U44, U45.

     

    I think this should work. Good luck,

     

    Robert

  3. Posted

    Aside question: I saw the insides of a 65XE for the first time yesterday.

    There appear to be spaces for extra RAM chips, so can a 65XE be made

    compatible with 130XE fairly easily by installing the chips?

     

    Yes, but aside the ram chips you also need a custom logic chip called CO25953 which drives the bankswitching.

     

    I think B&C still have them.

     

    Robert

  7. Posted

    I hate that so small number of ST games use overscan (probably due to the fact that it was discovered to late)  

     

    Left and right overscan is fairly difficult to use on an ST. To open the borders you need to synchronise your code with the electron beam. At the right electron beam positions you need to kick the video chip. So for each scanline you have code to open the left border, some other code or NOPs and at the end some code to open the right border. Since the timing is extremely critical you need to count the clockcyles of the inbetween borders instructions. Thus it is really difficult to interleave your normal code with the border opening code and works best with code that has a constant execution time. Code that has a variable execution time is extremely hard to interleave since you need code that counteracts the variable execution times. Thats why left and right overscan is almost only used in demos where the effects have a constant execution time. Interleaving game logic code is thus extremely hard.

     

    I know of one 3D demo in horizontal overscan but the trick here is that only about half of the screen is in horizontal overscan so the 3d code is executed outside the ovescanned scanlines where no electronbeam synchronisation is necessary.

     

    Opening the top and lower borders are much easier. Some games from mainly Thalion/Eclipse games used this (Lethal Xcess, Atomix).

     

    Robert

  11. Posted

    what kind of moster-atari is that?  8)

     

    Just an 800XL with 256Kb (old SIMM module). The 7-segment display shows which of the memory banks is selected. The two leds beside it indicate if the Antic or CPU access the extra memory.

    The two leds beside the cartridge slot indicate which cartridge bank is accessed.

    The row of six leds indicate IO access, OS rom on, OS rom access, Basic rom on, Basic rom access and selftest rom on.

     

    The four buttons on top are four extra cursors keys as found on a 1200XL I believe.

    The group of three toggle switches on the left selects between the original OS or one of the four extra OSses (APE Warp, 800 OS, etc.)

    Further an extra 800 style reset button (to freeze games that have disabled interupts).

    One of the two switches in the middle disables the memory expansion (some games that support 4 joystick ports (e.g. versions of The tail of Beta Lyrae) do not work with extra memory because they change the bankswitch registers to access the extra joystick ports).

    The other switch disables the cartridge slot (Usefull to boot a program that dumps the cartridge).

    Finally it has a build-in SIO2PC interface.

     

    The only things missing is a stereo Pokey and internal harddisk interface :-)

     

    Robert

  12. Posted

    Attached the disk version of International Karate (with all the backgrounds and the music at the correct speed on PAL machines).

     

    It was cracked by myself more than 13 years ago. As far as I remember it had quite an elaborate copy protection with multiple checks and encrypted code.

     

    And yes, the orginal disk had both the Atari and the C64 version.

     

    Robert

    international_karate.zip

  13. Posted

    Here a picture of the Turbo Freezer-XL which enables you to freeze almost every game and then use the disassembler to change the memory contents.

    After that you could continue the game with the alterations you made in the debugger.

     

    It also enables you to save a freezed game to (ram)disk and reload it later and start it from the saved point. I used it to save a game after each finished level. If I died, I just reloaded the last saved level and continued.

     

    More information and codes to be used with the Freezer/Atari800Win Plus emulator can be found here.

     

    Robert

  14. Posted

    I thought it was 32-bit with a 16-bit bus, thus both? :)

     

    Stone

     

    From a programmers point of view it is 32 bits. From a hardware point of view it is partially 32 bit and partially 16 bit. It has indeed a 16 bit external databus but the internal registers are 32 bit so external data access occurs in transfers of 16 bit.

    If the internal structure was totally 32 bit then instructions that only use registers should take the same time in 32 bit and 16 bit. But if you look at the clockcycle timings you will see that some instruction do indeed take the same time in 16bit and 32bit but other instructions take longer in 32bit than 16bit.

    So the 68000 in internally not completely 32bit because a lot of instructions are processed as two chuncks of 16 bit.

     

    However the Falcon has a budget version of the 68030. This one also has a 16 bit databus but is internally completely 32 bits.

     

    Robert

  16. Posted

    Cool video Robert, but you didn't show the "club selection" screen.  I think you hit "5" to get to that.  This would have been a great game had they finished it.

     

    I didn't knew that that was possible. I tried it and some other buttons have some effect too:

    1 or A - Toggles map or displays ground curving in putting mode

    4 or C - Club selection screen

    8 - Score card

    9 - Show Jack's advice

    0 - Statistics screen

    * - More help from Jack

    # - Leader - Board screen

     

     

    Robert

  18. Posted

    This might help.

     

    If you are playing Electra Glide on the "Atari800Win PLus" emulator type in the monitor window:

    C 2EF0 EA EA EA

    C 2EB1 EA EA EA

     

    Or if you are playing on a real Atari and have a "Turbo Freezer" type in the monitor:

    C2EF0<EA,EA,EA

    C2EB1<EA,EA,EA

     

     

    The first line makes that you won't slow down when you hit the road sides.

    The second line makes that you won't slow down when you hit the tunnel sides.

     

    Robert

  19. Posted

    I don't think a lynx is PAL or NTSC as it has it's own LCD screen.  But my lynx has an orange looking LED

     

    If you mix green light and red light you get orange light. So a Lynx is both PAL and NTSC :D

     

    Actually the Lynx display refresh rate is programmable by a set of timer registers making the refresh rate flexible. According to the docs, the maximum refresh rate is 78.7 Hz. Values for creating 75, 60 and 50 Hz refresh rates are given but they say that 50Hz seems to flicker badly on the Lynx LCD display. So probably most games use 60Hz as refresh rate.

     

    Robert

  21. Posted

    Hi Htbaa,

     

    Since it is already many months ago (march 2003 I think) I can't remember what I exactly sent you (unlike many others I have the bad habit to delete sent e-mail what I deem obsolete :) ). But according to what you wrote in this topic I suspect that I've sent you a 512Kb flashrom (29F040). When used you can have 4 banks of 128Kb. The two upper address lines (A17 (pin 30) & A18 (pin 1)) select with of the banks to use. Since on a Jaguar pin 1 & 30 are by default connected to Vcc, the fourth bank is selected if you just put the flash in without alterations to the motherboard. I probably programed BJL in the fourth bank so you should get BJL when you just plug in the rom.

     

    If the original rom doesn't work either, make sure that all pins are soldered good (make good contact and don't short circuit with another contact) and that no traces are broken (If you heat a contact to much the trace may come loose). Use a multi meter to check this.

     

     

    Robert

  22. Posted

    the link worked for me as far as showing me a page with a download link, but nothing happens when I click on it to actually download the movie. :?

     

    There is nothing wrong with the link but if you have installed Quicktime, it downloads the movie directly in the quicktime browser plug-in. Since the movie is quite big, this can take a while thus appearing that nothing happens. Just be patient or try left mouse click + save as to download it to your harddisk.

     

    Robert

  23. Posted

    Well, from the looks of that mod, I think I'm going to have to replace my '93 stubulator rom with a '94 one...why is that anyway? Is it because the '93 stubulator doesn't support the dev. Jagcd since it was still basically on the drawing board at that time? Or does it really matter and I can do the mod with my '93 stubulator rom regardless of what the mod instructions say?

     

    The Stubulator '94 is indeed needed with a CD-rom drive. The 93 version doesn't recognize the CD-ROM bios wether it is the normal or the developer bios.

    The 94 version works with the CD developer bios or the retail cd bios.

    With the stubulator 94 you can hold B while turning on the system to start a (unencrypted) cart directly. Hold C while booting to start the CD-bios.

     

    BattleSphere does indeed behave strange with the stubulator bios. Holding B does directly start JugsDD and boots an unencrypted CD instead of starting BSG.

    Maybe this behaviour is by design because in this way it is faster to boot unencrypted CDs than on a retail Jaguar. The Stubulator '94 / BSG combination starts the JugsDD directly while a retail bios / BSG combination first starts the regular cd-bios which in his turn starts BSG/JugsDD.

     

    Robert

  24. Posted

    If you view the boot track with ISO buster (sector view), at what offset does the ATRI header start. If it starts to early in the sector or maybe in the previous sector the CD-Bios won't find the boottrack. This happens when I copy a Jaguar CD with CloneCD 4.2.x and my Plextor writer. It writes the track earlier to the cd than then original. A normally written track with CD-record starts at offset $112 on my system.

     

    Try to create a copy of the CD by extracting all tracks with ISO buster, byte swap them and removing the zero bytes before the ATRI header and writing the tracks back to CD with CD-Record. Does this work?

     

    Robert

  25. Posted

    I was going to try to use R. Demmings software to make a simple boot image that loads a rom into an alpine when I was testing my alpine, but his software doesn't see my cdrw on XP. :(

     

    On Windows 98/ME you need to install Adaptec ASPI driver 4.60 (no later version).

     

    If you are using Windows XP, maybe you CD writer is not reporting itself with "CD-ROM" in the description line. Try to go to the options screen and enable the "Show all devices" option. Now the burn dialog shows all detected devices (even harddisks under XP).

    If it still doesn't show up, the CD writer may not be supported by CD-Record, the burner software used. To be sure open a command prompt and go to the installation directory. Then run: cdrecord -scanbus

    This shows the list of detected devices. If your CD-writer is found, please tell me the description shown by cd-record so I can add it to the detection routine.

     

     

    Robert

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