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Nickolasgaspar

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Posts posted by Nickolasgaspar


  1. 1 hour ago, Mclaneinc said:

     

    Most likely it will be fine but best practice to put the disk in or the old card insert.

     

    More of a worry is a: the courier and b: the psu if it comes with one. Most people pack the drive well but stick the PSU in the box loose, bad move, the psu weighs a ton and lose in transport, it's like having a wrecking ball in the box. pad the PSU up and if possibly make sure there's a little compartment it can be wedged in.

    Well the drive is already shipped. Let's hope the seller did a good packing  job. He has an excellent rate (ebay) so I want to think he knows what he is doing. The  good thing is that the drive comes without a psu.... minus one threat for things going wrong . Thanks for your time.

    • Like 1

  2. On 1/8/2022 at 4:27 AM, leech said:

    I'd just verify all the continuity between the pins and the board.  Within the db9 socket was where my pin was broken, so one of the axis were not responding.  Sounds like a similar issue.

    The update is....the Pokey was bad. I was tricked by 3 different Pokeys and their incompatibility issues between 3 boards? One pokey chip works great (touch tab)  in all three boards.

    The second pokey   in just two boards and the last one  doesn't recognize  tab inputs in all three boards.

    Really weird ....


  3. 12 hours ago, DrVenkman said:

    You don't need to "reverse engineer" anything except to compare the two versions of the Atari 800 Personality Board - early versions have standard 6502B chips and external logic for the HALT line; later versions use SALLY chips. The boards are interchangeable so the edge connectors are identical between the versions. 

     

    For that matter, the Atari 800 Field Service Manual has schematics for the whole system. Just read that. 

    To be fair, in the episode 3 he admits he is using a 400/800 cpu board as  a blue print. Well he is Dutch so maybe the "reverse engineer" statement is a "language barrier" issue.

     


  4. 8 hours ago, Stephen said:

    No it is not obvious - the 800 CPU card may have been pin compatible on the edge card.  I don't believe the 40-pin 6502 is pin compatible.  In fact, I know it is not.  You cannot swap the CPUs across both generations of cards.  You can't swap in a 1979 800 CPU in a 130XE.  I.E., the inside of the 6502 - the die, is different.

     

    EDIT:

    Damnit - beat me by a few seconds.

    Well I don't really understand how you "know it is not". You can literally  google the pinout of both versions and find out that Sally just uses two previously disconnected pins (#35,36)  to implement a specific function previously performed by 4 logic chips on the main board.

    Who knows what other changes were made. We weren't members of the "board" during that time to "know" anything. The Default Position in Logic is defined by the available evidence.

    The things we know about the "Liz" project, their identical pinouts, the ability to reproduce Sally's function by adding some external logic chips, the cost of designing and producing new CPU architecture while there was already a die available   and of course the use of the name "6502"...all provide sufficient and necessary evidence to dismiss further unnecessary assumptions.(Parsimony).

    Maybe there were additional changes...but the moment to accept that claim is only after we can put our fingers on objective evidence.

    A  C014377(400/800 models) is a standard 6502. The pins 35,36 are disconnected and there isn't a logic circuit on the XE mainboard to perform the needed function hence allow a 130xe to function.

    höltgen-abb4.jpg

    MOS6502-pinout.gif


  5. 5 hours ago, ijor said:

    Oh, I see.

     

    Putting "faster" chips (faster in the sense that they would match faster speed grades) wouldn't have affected the architecture unless you actually run the chip at a faster frequency. And as it was pointed out in this thread already, there are reasons why you would prefer faster chips even if you run them at the same slower frequency.

     

    That is not the sense I use the phrase "faster chips". When I say faster, I mean to run faster.

    Faster chips means more money. That makes no sense in our economic system even back in the 80s.


  6. 1 minute ago, ivop said:

    I was talking about the die of Sally. I.e. what's inside the chip. Did Atari copy the MOS die and added some 74xx circuitry (on the die), or did they design their own NMOS die?

    I think the answer is obvious since the early machines (400 800) came with a standard 6502 and those additional logic chips and the daughter board in this video can run on an XL machine with a standard 6502.


  7. On 5/5/2021 at 8:00 PM, ijor said:

     

    We talked about this already years ago, in this very same thread I believe. There is no such a thing as a 6502C core, or 6502B core for that matter. There are no speed grade specific cores or masks. All 6502 NMOS parts are essentially the same with very minor mask modifications. The speed grades are obtained just by binning (using a term that nowadays is very popular, but I'm not sure it was already used back then).

     

    Anyway, I doubt very much that Sally was specified for  4MHz, or even 3 MHz. That would have reduced the yield and increased the cost unnecessarily.

    I never said that our posts contradicted each other. In a discussion one can add to other people's comments.  I only pointed out that, independent of the method (binning or not)  6502s were graded and Atari's internal nickname (6502C) caused  confusion   and ambiguity specially when it was included in commercial documentation.

    There was also no reason to put binned cpus in Atari 8bit and C64 machines because it would affect the rest of their architecture. As far as I know the PCs were the first to allow such upgrades without the need of any daughter boards...and this was their recipe of success.


  8. 1 minute ago, DrVenkman said:

    You don't need to "reverse engineer" anything except to compare the two versions of the Atari 800 Personality Board - early versions have standard 6502B chips and external logic for the HALT line; later versions use SALLY chips. The boards are interchangeable so the edge connectors are identical between the versions. 

     

    For that matter, the Atari 800 Field Service Manual has schematics for the whole system. Just read that. 

    correct he oversold his efforts there....


  9. 8 minutes ago, ivop said:

    It would be interesting to know if Sally is just the known MOS 6502 die with some extra logic tacked to it, or not :)

    Ch

    Check this series of a guy restoring an Atari 800xl . In episode 3,4 and 5 he reverse engineers, designs and builds the circuit that is inside a Sally chip and uses it with a standard 6502. He literally uses 4 logic chips.

     

    btw this dude is the high priest of new age woo, Bernardo Kastrup. His philosophy may suck but he is a master in computer engineering.(actually he has a PhD on this).

    • Like 1

  10. The 6502C stands probably for "custom 6502".  I quote the relative article from atarimania.com

    "This chip was originally named SALLY by Atari engineers, but Atari
    Customer Support documents (Field Services Manuals) variously described it as
    "6502 (Modified)", "6502 Modified", "Custom 6502", or "6502C".  Field Service
    Manuals published by Atari, Corp./Atari Corporation reverted to using the
    chip's original name, SALLY, while Atari, Corp./Atari Corporation XE consumer
    owner's manuals (unfortunately) continued to use "6502C" in reference to the
    SALLY 6502.
    Several manufacturers produced the SALLY 6502 for Atari, including MOS
    Technology, Synertek, Rockwell, NCR, and United Microelectronics (UMC).  It is
    important to note that chips marked "6502C" such as the MOS Technology
    MCS6502C, MOS Technology MPS6502C, Synertek SY6502C, Rockwell R6502C, or UMC
    UM6502C are NOT the Atari "6502C" but rather equivalents to the standard
    MCS6502 that are certified for 4MHz operation.  Atari SALLY 6502 chips are
    never marked "6502C" but, other than the UMC UM6502I, always carry the Atari
    part number C014806."

    So using  letters(A,B,C) to grade 6502 by maximum speed IS a thing but it's not relevant to  Atari's C014806 variant. Its only for the standard 6502 cpus. We are talking about two different products.

     

    There is another variant that can only be found in early 400, 800 models which appears to be a standard 6502 cpu. The Sally chip  replaced a number of logic chips responsible for the same halt routine in those early models.

    The truth is that Sally chip exists only because of cost reducing practices.

    link:

    http://www.atarimania.com/faq-atari-400-800-xl-xe-what-are-sally-antic-ctia-gtia-fgtia-pokey-and-freddie_14.html


  11. 10 hours ago, xrbrevin said:

    ive never seen a 2x DRAM version nor a non-ECI version in the UK. ive only ever seen ECI'd 8x DRAM with 8x unpopulated - easy upgrade to 128k 🙃

    the 2x DRAM version is referenced in the schematics:

     

    130xe.zip 2.57 MB · 2 downloads

    I found pictures of  the last XE model, the 800XE(its an 65XE in Eastern Europe). They used the 130xe mobo with only two DRAM chips and the ECI port.

    I have an 65XE with a Freddie Chip and without an ECI port, so I was wondering if there are any XEs versions released without a Freddie chip.

    It looks like there aren't any.

     

    http://oldcomputer.info/pictures/index.php?spgmGal=Museum/8-bit/Atari_800XE&spgmPic=5

    index.jpg


  12. Just now, xrbrevin said:

    yes all XEs use the Freddie chip. Some late model 800XLs have it too. They are sometimes referred to as 'XLF'

    for variations of the 65XE, some had no ECI port, some had 8 DRAMs - some had 2, some had unpopulated DRAM locations on the PCB for an extra 64k - some didnt, some were made for arabic text

    Yes, I happen to  have an 800xlf board. So there are variations of the 65XE with 2 DRAMs? Is there a way to tell the difference without opening the machine? Do you have a link to check the board of this version?


  13. On 7/10/2021 at 6:18 PM, mikesk8 said:

    I have both Atari 800 (stock) and 130XE (stock) and both are amazing in their own way :) 

     

    Atari 130XE (or 65XE or late 800XL with Freddie) gives you basically all out of the box: svideo and min 64kb provides access to almost all programs. The earlier XE had springs in keyboards (I have one of those) and this keyboard is not bad at all. The quality of plastic, keyboards and motherboards is not like in 800 (XL is visibly better), but they work without issues. This is the best value for money in my opinion. 

     

    Atari 800 is one of the most beautiful vintage computers (more than 1200 :) ) to me and the build quality is superb. However, if you want to have it as a daily runner you really need to mod it, which is rather expensive. 

     

     

    Do you know if all 65XEs come with Freddie chips or are there any versions without?


  14. 2 hours ago, rensoup said:

    Kudos rensoup! Amazing work!

    I will chip in some helpful info on the SIO2PC options needed for the loading process..

    First of all, the loading of the game is rock solid now(I hope those Altirra logs I sent did help!)

    The game (DD file version) loaded on two different machines (Atari 800XL and 65XE both with Freddie chips) while using two different SIO2PC programs and devices.

    They both rock Jurgen's memory upgrade (512 KB SRAM memory expansion V4.4 Standard)

     

    I used the AspeQt on  a android phone. Two  options  are crucial here.

    (Tool>options)

    1 . The Handshake method needs to be set on "SOFT".

    2.  The "High speed mode baud rate" needs to be 19200. Any other speed will dramatically slow down the loading process.

     

    In the case of RespeQt(winPC) nothing can really affect the loading process!!!

    Again thank you for the amazing work!

     

    • Like 1

  15. Since my first job was  creating digital illustrations I have to say that I do love C64 still images. The higher resolution, the earthy colors and creative use of that grey and purple colors produce real art in my opinion. I really appreciate creative art  on limited resources. But again the problem is that there aren't enough colors to produce dramatically different results, without ignoring advantage of  the higher resolution in the detail of these images.

    On the other hand, images on the Atari 8bit line are a bit more "rough"  from a resolution perspective but the available hues and colors can  produce a huge spectrum of different color schemes.

    Here is a great image from Lamer's demo "Prozac".(Scrolling picture).

    If you check this thread you will see many examples of converted still images. Of course they are not "art" but they can roughly  show the  abilities of the hardware to produce images in a variety of different color schemes.

    An other great example is the conversion of the  "Defender of the Crown" title screen.

    prozac.thumb.jpg.6f323210dd1792a777473ed3732fc50d.jpg

     

    • Like 1

  16. This thread's title is about the graphics abilities of two 8 bit micros.  I threw in CPC because even coders of that period accepted CPC's superiority over C64's capabilities. (Virgin Software quote in the video below).

     

    The homebrew community has proven that all 8bit machines are capable game machines and provided a larger pool of "data" for our evaluations. Some are better in specific genres than others.

    Sure, scrolling looks great on C64 and Atari machines with their dedicated  hardware, Pseudo 3d and scaling is superior on atari 8bit computers due to Miner's advanced architecture(I saw a new C64 racing game with impressive scaling), and "16bit" like appearance is CPC's strong point  without having many serious drawbacks in  scrolling or sound.  

    In my opinion and based on  old and new game library , the Atari 8bit line and the CPC are  the most balanced machines since  they both score really high in all categories (graphics/colors,scrolling/scaling,sound).

    Of course we are forgetting MSX2 machines with their objectively  superior graphics and Speccy's  aesthetic which is so unique and artistic in so many instances.

     I would be equally happy owning any  of the 8bit classics micros but I have to admit though,  in the case of the C64, its the support this machine enjoyed  during his commercial life not its graphics  that would justify my satisfaction.

    Well I don't really play games anymore(I just test them for some secs) so  my critique is solely  based on my initial impressions on their graphics, sound and control response.

     

     

     

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