Jump to content
Have You Played Atari Today?
2600|5200|7800|Lynx|Jaguar|Forums|Store  

Xebec

Members
 View Profile  See their activity

  • Content Count

    522

  • Joined

  • Last visited

Posts posted by Xebec

  1. Posted

    I don't think it'll work without an additional circuit due to the fact that Atari's 6502 "SALLY" has a 'halt' pin/function that the standard 6502. The 6510 does not appear to have this HALT Pin either.

     

    The exception might be the 'early production Atari 400/800' machines which actually used a regular 6502C and had the circuitry on the board instead of the CPU.

     

    https://www.atarimax.com/jindroush.atari.org/achsally.html

     

    Description
    6502 is the heart of the computer. It's based on MOS Technologies 6502. While the 400/800 models contain a generic 6502 CPU, all of the XL/XE models contain Atari's customized 6502C chip. 6502c has an extra line called HALT. It is controlled by ANTIC which it uses whenever it needs the /jindroush.atari.org/data/address bus. The HALT line must be pulled high for the chip to work. Early 400/800 NTSC computers used a standard 6502 and 4 additional chips to stop the processor when ANTIC needed the busses.
    • Like 2

  2. Posted

    Here is the plain CEC (not CEC-"Expansion")

     

    http://finapple.hho.fi/finapple/index.php/2017/06/09/cec-i-china-education-computer-part-1/

     

    There are two models that i am aware of (Apple II clones that is) made by the Shaanxi Province Computer Factory and Huaming Computer Co.
    – CEC-I – made in beige and red colors
    – CEC-E – made in beige color, more rare of the two.

     

    6502, 1 mhz, 64k ram (2 x 64kx4), 32KB ROM (seems pretty big), PAL video.

     

    Here's a white CEC-I from that same site:

    http://finapple.hho.fi/finapple/index.php/2017/08/22/cec-i-beigewhite/

     

    Looks like the CEC-E Is CEC-I with additional disk / accessory ports on the back..

    • Like 2

  7. Posted

    The screen refresh will be ~ 50 Hz instead of ~ 60, so the TV or monitor mightn't work properly. Rolling screen on CRT a common sign it's not going to work.

     

    The colour encoding should be correct but still no firm guarantee you'll get colour.

     

    The overall machine speed will be slightly faster than a stock PAL machine but be unnoticable.

     

    The hardware register, for whatever reason, that most software uses to distinguish PAL or NTSC is in fact on the GTIA chip so software might still ID it as an NTSC machine. Though most software either doesn't check or doesn't care. Generally modern games and demos that aren't NTSC compatible just don't work rather than telling you that it's the wrong system.

     

    Full PAL conversion - the PAL GTIA, and on PAL machines the colour is derived from a seperate crystal so you'd need to change the master crystal and add the colour one. And depending on machine, the extra circuitry might not necessarily be present.

     

    I believe a few people have converted 1200XLs to PAL - which is something that never existed in the day, so worth hunting down such threads.

     

    OK - in my test case i'm getting color output and The Last V8 is actually winable now.. so i assume the only difference between ANTIC SWAP and 'FULL PAL' is exactly correct speed (1.77mhz vs 1.79), the ability to pass the PAL check if needed, and that's it? almost all PAL software should be happy and color-correct with that?

  9. Posted · Edited by Xebec

    Atari 800, 800XL.. BBS Dial-up, then ran a BBS on the Atari 8bit. Continued running the 8bit BBS Express as I got a 520ST then later put the BBS on the 520ST and bought a 1040ST.

     

    Unfortunately the only Amiga exposure I had was with a family member who had the 1000 and the only game they had was Rogue.. which didn't show any special capabilities :(. I'll admit I was actually very initially disappointed with the ST but as I came across Sundog, Dungeon Master, and the Word processing software (and mono monitor) became pleasantly surprised with what the machine could do..

     

    Moved the BBS to PC in 1990, and the ST faded from use shortly thereafter (though i had my ST and 8bit set up and running occasionally until I was busted for running a pirate BBS In 1994 :) ).

     

    .. by the end of 1990 i had a 486dx-25, 4mb ram, 676mb SCSI Drive, a soundblaster, and tseng 4000 chip graphics card.. it was very powerful at the time but it took a few years before proper games came out for it..

  10. Posted

    Hey folks --

     

    I know a quick way to run some PAL software properly timed on a NTSC Machine is to simply swap the ANTIC chip with a PAL ANTIC.

     

    What are the main drawbacks of this? I believe the color palette is a bit off? (is it close or massively off?) what other drawbacks?

     

    And what is required for a 'full PAL conversion' ?

     

    Thanks..

    John

  11. Posted · Edited by Xebec

     

    There was a simple hardware modification to the ST called (Autoswitch) Overscan or (Auto) Lacescan that provided custom screen resolutions. I have no idea why Atari didn't incorporate this into the GSTSHIFTER when developing the STE models or why they didn't add a 160x200 pixel 256 colour mode, though.

     

    Very interesting on the mods. I will have to look into these for curiosity.

     

    and I agree on the higher color mode, the 16 color mode felt limited after starting life with an Atari 800.

     

    If I had to guess on the original ST 160x200 pixel/64-256 color mode though it probably has to do with the machine being intended as a business machine, and a desire to run everything under TOS (at least in concept). I really did learn to enjoy the 640x400 70hz mono though..

     

    Good question on the STE.

  12. Posted

     

    And today the PC is the standard. The PC schooled Atari and Commodore right out of business. Heh. We were right to let those architectures fade away.

     

    The article is right, the ST is an oddball design. And the Amiga is a bag of one-trick wonders, never having the necessary bandwidth and power to bring it all together.

     

    Atari and Commodore computers were toys, none of them could handle big business, or even small business.

     

    The Amiga's multitasking OS, flexible colors/graphics resolutions, and 32-bit processor gave the machine plenty of power for business.. but the apps weren't really there.

  13. Posted

     

    Yes, a few years later (1989), I was working at a store named Compucentre in Metrotown Mall (in Vancouver). We sold everything--C64's, Macs, Apple //e, Compaq, IBM PS/2, Atari and Amiga. Even NES, Atari 7800, TurboGrafx, SMS and Genesis consoles. All of the salespeople had their niches... mine was the ST. I had the Snowman video, and that combined with promises of IBM and Mac compatibility (had the CP/M and C64 emulators, too) helped me sell a fair number of them. I wish I had a few more demos because I sure got sick of that Snowman demo. LOL

     

    LOL .. Great memory and thanks for sharing! The late 80s were awesome for choice.

     

    I was on the younger side so my experience was the sadness of watching the Atari software shelves slowly shrink to nothing every time we visited the mall. But tons of good memories actually using the ST (and 8bit) with Dad!

    • Like 2

  14. Posted

     

    What advantages? Besides being cheap, its advantages were all *potential* advantages, with very little software to exploit it. Don't get me wrong, I lusted after it, still love the ST, but I remember going into the computer shop and looking at the software shelf (and a small one at that), and thinking "that's it?"

     

    Our dealer didn't have anything to really show it off until he got a copy of Sundog, then King's Quest. That's when he started moving units. Until then, it just sat at the TOS screen in low res-- I think he was embarrassed to boot ST BASIC for me to play with.

     

    It is unfortunate the ST didn't really launch with demos or similar stuff that were already known to help sell the 8-bit computers before..

     

    I'm assuming in 1985 there was not even a MIDI sequencer software ready for the ST..

  16. Posted

    I think the dealer network situation for Atari, lack of early investment, and Tramiel getting distracted with Federated Group basically did the ST in. IMO, Federated destroyed Atari's cash reserves making them less interested in engineering/product work, and the dealer network being leery of Atari/Tramiel made it harder to get the ST's out there in the mass quantities needed.

     

    A little more useful advertising and grass roots movements would have helped a lot, and GEM not getting any real investment was also terrible.

     

    The Amiga was by far the most powerful home computer of 1985, but the ST had just as much potential for sales because it was already cheap to manufacture and had a clean/responsive GUI out of the box.

  18. Posted

    Just an odd thought. In the 1990s OEMs were making 'webTVs' -- some combination of slow (but cheap) computer and modem that would allow you to browse the web on TV.

     

    What would it have taken to put a small terminal program and a modem together with a 2600 as an upgrade to provide a dirt cheap 'dial/use a BBS' on a TV experience? (cheaper than a low end computer at the time)

     

    My thoughts:

    - Resolution probably too low even for 40 column text

    - Keyboard via joystick ports

    - Modem would have to be something build into the cartridge

    - more RAM Needed even for a very basic terminal program (but probably not a lot of RAM for very basic functionality?)

     

    Would there have been another computer/console in the early 80s (pre-NES) more suitable for something like this? 5200 seems like it'd be too expensive..

  19. Posted

    I'm curious - Not sure if others have seen, but a high school student was recently able to acquire enough parts to actually fab 10 micron chips in his garage:

     

    https://hackaday.com/2017/02/25/the-fab-lab-next-door-diy-semiconductors/

     

    If you go to his blog or read elsewhere, he says he can do down to 1 micron but would require some kind of a clean room for this: http://sam.zeloof.xyz/maskless-photolithography-with-dlp-projector/

     

    For reference, the Amiga original chipset chips were 5 micron, and I believe even AGA Lisa was 1.5 micron. The Atari custom chips are surely older than 5 micron..

     

    So does this mean there could be some kind of reasonable cost path to eventually re-fab some of the old chips that are irreplaceable? and would that be cheaper than simple/low end FPGAs set up in a compatible pinout?

     

     

    • Like 3

  20. Posted

    Sophia Rev.C DVI on a Dell 1905FP. All I can say is WOW!

     

    Is that the 1280x1024 Sophia or a different setting that happens to scale that way?

     

    I'd like to order one of these, and have 1280x1024 monitors now, but also want the ability to connect to 16:9 monitors in the future..

  22. Posted · Edited by Xebec

    What kind of things happen if you put this on a 16:9 monitor but have the 5:4 resolution?

     

    If you have the 1280x1024 version -- does it just output with borders around? or stretch? does it depend on the monitor?

     

    and is there any way to reprogram with your own equipment if you need in the future?

     

    And any chance this would work on the Atari 800 original also? I *think* there's room inside the case to push out the GTIA a bit..

  24. Posted

    I'm trying to have some fun with my staff meetings at work.. and I thought hooking an Atari 8-bit running a game or a demo to one of the wall monitors would be something fun for the group :). Unfortunately it looks like they only expose HDMI where I work..

     

    Are there any good / reasonable cost methods for hooking any Atari 8bit up to HDMI?

     

    I don't know if the monitors support analog over HDMI so VBXE is probably out..

    • Like 1
AtariAge
Forums
Store
General
Follow AtariAge

Copyright ©1998-2021 AtariAge

×
×
  • Create New...