1. Forum
  2. Usenet
  3. COMP.SYS.IBM.PS2.HARDWARE

  • You're not heavy, you're my brother [piggybacked VRAM on MCGA?]

    From Louis Ohland@21:1/5 to All on Sun Feb 13 21:45:16 2022
    Can we piggyback VRAM on MCGA?

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From WBSTClarke@21:1/5 to Louis Ohland on Mon Feb 14 02:26:08 2022
    On Monday, 14 February 2022 at 03:47:35 UTC, Louis Ohland wrote:
    Can we piggyback VRAM on MCGA?

    Talk to David Beem.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Louis Ohland@21:1/5 to WBSTClarke on Mon Feb 14 09:07:37 2022
    I do not know of this "Beem" you speak of...

    There is a buzz-kill, can the controller handle more than 64K?

    Seems like a "Star Trek" episode, where Scotty is told "Warp power now,
    or we're all dead!"

    On 2/14/2022 04:26, WBSTClarke wrote:
    On Monday, 14 February 2022 at 03:47:35 UTC, Louis Ohland wrote:
    Can we piggyback VRAM on MCGA?

    Talk to David Beem.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Louis Ohland@21:1/5 to WBSTClarke on Mon Feb 14 10:00:08 2022
    Really? ;)

    Maybe you can tell me who "WBST" is...

    This MCGA is the quintessential challenge, trying to squeeze more
    performance out of period hardware. If it is in possible...

    On 2/14/2022 09:51, WBSTClarke wrote:
    On Monday, 14 February 2022 at 15:09:56 UTC, Louis Ohland wrote:
    I do not know of this "Beem" you speak of...
    a.k.a. IBMmuseum

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From WBSTClarke@21:1/5 to Louis Ohland on Mon Feb 14 07:51:06 2022
    On Monday, 14 February 2022 at 15:09:56 UTC, Louis Ohland wrote:
    I do not know of this "Beem" you speak of...
    a.k.a. IBMmuseum

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From IBMMuseum@21:1/5 to All on Mon Feb 14 12:16:59 2022
    This MCGA is the quintessential challenge, trying to squeeze
    more performance out of period hardware. If it is in possible...

    To add(ress) increased VRAM, then you need more modes. Even for the "smooth scrolling" that PCRetroTech has done almost 35 years later, he found one game advertised for MCGA required a 286 CPU (which doesn't exist coupled with MCGA - an NEC V30 for 80186
    op-codes is as high as you can go). The Epson Equity 1e is the most recent implementation of MCGA, and they still used the same VRAM size (adding another bit of addressing means doubling the VRAM to 128Kb) and modes.

    The Chips and Technologies "Model 30" chipset (82C100) left the video implementation out, even with the company being known early-on for video chips (https://en.wikipedia.org/wiki/Chips_and_Technologies). For the Model 30, IBM just had the "PS/2 Display
    Adapter" to step up to VGA. But sure, revisit something that wasn't updated in the 35 years it has existed.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Louis Ohland@21:1/5 to IBMMuseum on Mon Feb 14 18:05:26 2022
    More modes, or another way to address the extra memory?

    You brought up the addressing bits. That might complicate things...

    On 2/14/2022 14:16, IBMMuseum wrote:
    need more modes

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From IBMMuseum@21:1/5 to All on Mon Feb 14 16:20:19 2022
    More modes, or another way to address the extra memory?

    You brought up the addressing bits. That might complicate things...

    You could come up with an "X" mode convention yourself, just like PCRetroTech did - He knows CGA quite well (a recent project he worked on for two years recently popped up). I would bet that the MCGA controller can't handle VRAM addressing over 8bits,
    however.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Louis Ohland@21:1/5 to IBMMuseum on Mon Feb 14 19:39:20 2022
    Rain on my parade.

    On 2/14/2022 18:20, IBMMuseum wrote:
    I would bet that the MCGA controller can't handle VRAM addressing over 8bits, however.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Alexandros@21:1/5 to Louis Ohland on Tue Feb 15 05:42:45 2022
    Louis Ohland <ohland@charter.net> wrote:
    Rain on my parade.

    On 2/14/2022 18:20, IBMMuseum wrote:
    I would bet that the MCGA controller can't handle VRAM addressing over 8bits, however.



    Reach out to TubeUs who has created the Gremlins Graphics adapter which emulates MGA/CGA/EGA if he could extent to support MCGA (with more memory?)
    and says he has the gate array images to do this. It is in his plans but somewhere in the back of his queue.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Louis Ohland@21:1/5 to Alexandros on Mon Feb 14 23:49:40 2022
    https://twitter.com/tubetimeus/

    On 2/14/2022 23:42, Alexandros wrote:
    Louis Ohland <ohland@charter.net> wrote:
    Rain on my parade.

    On 2/14/2022 18:20, IBMMuseum wrote:
    I would bet that the MCGA controller can't handle VRAM addressing over 8bits, however.



    Reach out to TubeUs who has created the Gremlins Graphics adapter which emulates MGA/CGA/EGA if he could extent to support MCGA (with more memory?) and says he has the gate array images to do this. It is in his plans but somewhere in the back of his queue.


    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)