serial terminal out of an LCD display? - CP/M

This is a discussion on serial terminal out of an LCD display? - CP/M ; Greetings, I've seen lots of surplus LCD screens from notebook designs out there and was curious if anyone has done or seen a design of a simple 80 x 25 serial terminal with the LCD as the display. I've read ...

+ Reply to Thread
Results 1 to 13 of 13

Thread: serial terminal out of an LCD display?

  1. serial terminal out of an LCD display?


    Greetings,

    I've seen lots of surplus LCD screens from notebook designs out there
    and was curious if anyone has done or seen a design of a simple 80 x
    25 serial terminal with the LCD as the display. I've read that most
    LCD terminals are proprietary designs, but I would think by now that
    someone has cracked this issue. I have seen small LCD displays with
    16 x 2 ascii characters that take simple pic controllers to run, but
    have not seen useful larger sized terminals.

    tnx,
    john

    --


  2. Re: serial terminal out of an LCD display?

    It's possible but not economically feasible. This has been discussed ad
    nauseaum in many newsgroups. You need a video driver card (VGA or DVI
    or RS-232 or whatever to LCD), a power supply and some specialized
    cabling. The cost of doing this "one off" far exceeds the cost of a new
    LCD monitor. And it far exceeds the cost of an inexpensive laptop on
    E-Bay (which can also do this task very well using Hyperterm or other
    terminal emulation software). You can buy used laptops on E-Bay that
    will do this WELL, with color LCD screens, for $10 to $25. All you
    want, hundreds of them (and a new selection daily).


    jaevans wrote:
    > Greetings,
    >
    > I've seen lots of surplus LCD screens from notebook designs out there
    > and was curious if anyone has done or seen a design of a simple 80 x
    > 25 serial terminal with the LCD as the display. I've read that most
    > LCD terminals are proprietary designs, but I would think by now that
    > someone has cracked this issue. I have seen small LCD displays with
    > 16 x 2 ascii characters that take simple pic controllers to run, but
    > have not seen useful larger sized terminals.
    >
    > tnx,
    > john
    >


  3. Re: serial terminal out of an LCD display?

    >> I've seen lots of surplus LCD screens from notebook designs out there
    >> and was curious if anyone has done or seen a design of a simple 80 x
    >> 25 serial terminal with the LCD as the display.


    I too thought that would be a neat idea until I saw that the
    timing is rather annoying (requiring a specific controller)
    and the ribbon connectors are hard to re-use.

    I was given what looks like a laptop computer
    but it's just a terminal: keyboard and LCD.
    I've had few reasons to use it since a laptop running
    DOS and Procomm is much more versatile
    (save logs, file transfer, emulate various terminals).

    Even the lcd4linux folks prefer using non-graphic
    LCD modules with the piggyback controller.
    --

    -- mejeep deMeep ferret!

  4. Re: serial terminal out of an LCD display?


    Barry Watzman ha scritto:

    > terminal emulation software). You can buy used laptops on E-Bay that
    > will do this WELL, with color LCD screens, for $10 to $25. All you
    > want, hundreds of them (and a new selection daily).
    >


    But imagine this: take a cheap used laptop, throw away x86 motherboard
    and replace it with a (home brewed) Z80 one........

    Piergiorgio


  5. Re: serial terminal out of an LCD display?

    pbetti wrote:
    > Barry Watzman ha scritto:
    >
    >> terminal emulation software). You can buy used laptops on E-Bay
    >> that will do this WELL, with color LCD screens, for $10 to $25.
    >> All you want, hundreds of them (and a new selection daily).

    >
    > But imagine this: take a cheap used laptop, throw away x86
    > motherboard and replace it with a (home brewed) Z80 one........


    No, use it as is. Just build a system that boots a z80 emulator,
    and you will have something much faster than any available Z80.
    Make it a 64180 emulator.

    --
    "If you want to post a followup via groups.google.com, don't use
    the broken "Reply" link at the bottom of the article. Click on
    "show options" at the top of the article, then click on the
    "Reply" at the bottom of the article headers." - Keith Thompson
    More details at:
    Also see



  6. Re: serial terminal out of an LCD display?


    CBFalconer ha scritto:

    > No, use it as is. Just build a system that boots a z80 emulator,
    > and you will have something much faster than any available Z80.


    A-ha! Good idea. Feasible. Less amusing howewer, you loss the hardware
    part.

    Piergiorgio


  7. Re: serial terminal out of an LCD display?

    Just to remain on topics i remember that Hal Bower on his page describe
    the kind of beast we are talking about. Quoted from
    http://home.att.net/~halbower/ :
    "In spite of the derision received from those dealing with larger word
    sizes, 8-bitters are up to many tasks such as this YASBEC-based laptop
    with the computer controlling an ISA 8-bit LCD controller with Z-System
    termcap emulation. A 40 MB SCSI hard drive and 3.5" HD floppy are
    included. Power is regulated internally with National Semi "Simple
    Switcher" circuits from a nominal 12 vdc source."
    But he does not exaplain how the magic is done. There's someone who
    knows?

    Piergiorgio


  8. Re: serial terminal out of an LCD display?

    On Fri, 19 May 2006 18:00:34 GMT, Barry Watzman
    wrote:

    >It's possible but not economically feasible. This has been discussed ad
    >nauseaum in many newsgroups. You need a video driver card (VGA or DVI
    >or RS-232 or whatever to LCD), a power supply and some specialized
    >cabling. The cost of doing this "one off" far exceeds the cost of a new
    >LCD monitor. And it far exceeds the cost of an inexpensive laptop on
    >E-Bay (which can also do this task very well using Hyperterm or other
    >terminal emulation software). You can buy used laptops on E-Bay that
    >will do this WELL, with color LCD screens, for $10 to $25. All you
    >want, hundreds of them (and a new selection daily).
    >
    >
    >jaevans wrote:
    >> Greetings,
    >>
    >> I've seen lots of surplus LCD screens from notebook designs out there
    >> and was curious if anyone has done or seen a design of a simple 80 x
    >> 25 serial terminal with the LCD as the display. I've read that most
    >> LCD terminals are proprietary designs, but I would think by now that
    >> someone has cracked this issue. I have seen small LCD displays with
    >> 16 x 2 ascii characters that take simple pic controllers to run, but
    >> have not seen useful larger sized terminals.
    >>
    >> tnx,
    >> john
    >>


    Economicas are not the question.

    I happen to have a nice 640x480 mono laptop LCD and I've looked at
    what it takes to drive it and it's trivial. the icky part is the
    display is organized as two sections each having it's own memory and
    serializerbut sharing common V and H clocking. Simple circuits,
    lots of them and hard to address in software as the display space is
    really two. I've also loked at the latest Color ones and they are
    insane.

    The cheapest way to do it would be a mono or color 5-7" used for DVD
    players as they take direct video (like old tube monitors) and drive
    them just like we did using 64x16 or 80x24 cards of S100 fame or
    similar.

    Allison



  9. Re: serial terminal out of an LCD display?

    On 22 May 2006 01:14:58 -0700
    "pbetti" wrote:

    > Just to remain on topics i remember that Hal Bower on his page
    > describe the kind of beast we are talking about. Quoted from
    > http://home.att.net/~halbower/ :

    [snip]
    > But he does not exaplain how the magic is done. There's someone who
    > knows?


    Short Explanation: Start with a VGA display and 8-bit ISA (original IBM
    PC bus) controller for the display. There appears to be a suitable
    combination from MVS (from a CircuitCellar ad, www.star.net/people/~MVS)
    for $195, although the two I have used came from Earth LCD
    (EarthLCD.com). Also get the technical/programming manual on the
    particular LCD controller chip used in the ISA adapter since you will
    need it to program the replacement ROM (or discrete driver).

    Make an interface from the ISA bus to whatever interface you need on the
    8-bit computer. Since I used Z180's in both my implementations (the
    computer on the above cited web page and a stand-alone terminal), the
    adapter needed to do three basic things:
    1 - interface the address and data busses as well as strobe conversions
    (read/write, io/mem, reset inversion, address decode for next items all
    done in a 16V8 GAL)
    2 - 8255 for either parallel keyboard (from an 8748 decoder used in
    laptop) or I/O matrix decode of switch contacts used on keyboard
    (terminal with main CPU debounce, delay and conversions).
    3 - A little beeper made from a 556 dual-555 timer. When a strobe from
    the address decoder hits it, it gives about a 1/2 second 800 Hz beep.

    With the Z180, all 20 address lines are carried through, and the
    computer (or main processor) limits itself to 512 KB of memory so that
    the MSB (Bit 19) can be used to read/write to the expansion and the ROM
    extension address of E0000-E8000H and Video RAM of B0000-B8000 can
    remain intact and be used as is. In both of my installations a single
    512k x 8 SRAM was used in the main processor addressed at 0-7FFFFH.

    For the computer, I implemented BIOS and boot ROM routines to access the
    terminal. CONOUT sends a character which is inserted into a data
    structure which includes an attribute byte (for gray scale color, blink,
    hilite, etc), display page and address per PC specs. Also needed in the
    BOOT rom is a program to properly initialize the display. I chose to
    rewrite the ROM on the controller for the computer and included
    'functions' in the data structure which allow me to change the display
    to other than 80x25 resolution, and I frequently use 33x42 or something
    like that (I'm going from memory now) when programming. When modes are
    changed, the resolution is also changed in the ZCPR Termcap definitions
    which emulate three types of terminals (H-19, Wyse and ANSI/VT10x).
    Other 'functions' allow cursor repositioning, reading character at
    cursor and a few other things. Since the controller chip on the
    EarthLCD controller will not function at the full speed of a Z180, one
    memory wait state needs to be added at 9.216 MHz (18.432 MHz crystel)
    and two memory and one additional IO wait states are needed if the
    processor is running at 18.432 MHz with a Z8S180 and the div-by-2
    circuit bypassed). Performance seems to be slightly slower than a
    serial terminal at 19.2 kbps in overall usage, but things such as
    scrolling are slowed by the DMA memory moved in the onboard video RAM ..
    slow...

    For the Terminal, I used an old controller board that used 16-bit
    addressing decodes on-board and the clock chip (62421) conflicted with
    an address used in the VGA adapter alternate setup port. To overcome
    clock corruption, I resorted to reading and saving time/date,
    initializing VGA, restoring time/date. The terminal uses only the
    single Z180 to control display, keyboard scan/debounce and conversion,
    seriol I/O to and from an onboard ASCI with MAX233 voltage conditioning
    on RS232 IO, and a couple of lines from the 8255 for status LEDs. A
    screen-oriented setup/configuration screen is used to set baud rates (up
    to 38.4 kbps in hi-speed mode with the div-by-2 bypass in the Z8S180),
    terminal emulation mode, hi/low speed of the Z180 and a few more things.
    The little controller had a EEPROM (24Cxx) on it, and it was used to
    store configuration parameters. The 62421 RTC was used during power-up
    to measure the CPU clock speed, and when setup is exitted to insure that
    the CPU is functioning correctly (e.g. will not allow the Hi-Speed mode
    if the Z8S180 register is not present). All of the software fit in a
    27256 EEPROM including all of the LCD control software, so the ROM on
    the VGA adapter was not used.

    I hope this provides some insight into how it has been done here. The
    laptop is the most-used machine in my 8-bit inventory and was shown at
    the Trenton Computer fest in 1997, the year that the CP/M sessions were
    discontinued so it was in a 'hardware' forum.

    Hal

  10. Re: serial terminal out of an LCD display?

    > The cheapest way to do it would be a mono or color 5-7" used for DVD players as they
    > take direct video (like old tube monitors) and drive them just like we did using 64x16 or
    > 80x24 cards of S100 fame or similar.


    Good idea indeed. Here in Europe the German company Conrad sells 8"
    colour LCD screens for 200 Euro that have video _and_ VGA input.


    --
    ___
    / __|__
    / / |_/ Groetjes, Ruud
    \ \__|_\
    \___| URL: Ruud.C64.org


  11. Re: serial terminal out of an LCD display?

    On 23 May 2006 03:15:49 -0700, Ruud.Baltissen@abp.nl wrote:

    >> The cheapest way to do it would be a mono or color 5-7" used for DVD players as they
    >> take direct video (like old tube monitors) and drive them just like we did using 64x16 or
    >> 80x24 cards of S100 fame or similar.

    >
    >Good idea indeed. Here in Europe the German company Conrad sells 8"
    >colour LCD screens for 200 Euro that have video _and_ VGA input.


    So far teh cheapest source here (USA) for small screens are those
    designed for auto use (DVD players). They seem to run in the
    60-125$US range though I"ve heard of cheaper. Takes video in
    from small cameras so any card (or hb design)? that can do RS170
    video works with them.

    Allison



  12. Re: serial terminal out of an LCD display?


    wrote in message
    news:1gt572p3757neu1i2910rhpi0a58np43hi@4ax.com...
    > On 23 May 2006 03:15:49 -0700, Ruud.Baltissen@abp.nl wrote:
    >
    >>> The cheapest way to do it would be a mono or color 5-7" used for DVD
    >>> players as they
    >>> take direct video (like old tube monitors) and drive them just like we
    >>> did using 64x16 or
    >>> 80x24 cards of S100 fame or similar.

    >>
    >>Good idea indeed. Here in Europe the German company Conrad sells 8"
    >>colour LCD screens for 200 Euro that have video _and_ VGA input.

    >
    > So far teh cheapest source here (USA) for small screens are those
    > designed for auto use (DVD players). They seem to run in the
    > 60-125$US range though I"ve heard of cheaper. Takes video in
    > from small cameras so any card (or hb design)? that can do RS170
    > video works with them.
    >
    > Allison
    >
    >

    If you don't need the large screen of a laptop, a simple serial terminal can
    be a Palm Pilot. Any of the older models with the serial hot sync connector
    works fine. I have modified some of them with a short pigtail soldered to
    the connector fingers and a DB-9 connector. The original connection was
    terrible. I use them as test sets. The CASL software development
    environment allows one to do GUI if wanted. A terminal emulator does fine
    if you don't need GUI.

    Don



  13. Re: serial terminal out of an LCD display?


    > wrote in message
    > news:1gt572p3757neu1i2910rhpi0a58np43hi@4ax.com...
    > > On 23 May 2006 03:15:49 -0700, Ruud.Baltissen@abp.nl wrote:
    > >
    > >>> The cheapest way to do it would be a mono or color 5-7" used for
    > >>> DVD
    > >>> players as they
    > >>> take direct video (like old tube monitors) and drive them just
    > >>> like we
    > >>> did using 64x16 or
    > >>> 80x24 cards of S100 fame or similar.
    > >>
    > >>Good idea indeed. Here in Europe the German company Conrad sells 8"
    > >>colour LCD screens for 200 Euro that have video _and_ VGA input.

    > >
    > > So far teh cheapest source here (USA) for small screens are those
    > > designed for auto use (DVD players). They seem to run in the
    > > 60-125$US range though I"ve heard of cheaper. Takes video in
    > > from small cameras so any card (or hb design)? that can do RS170
    > > video works with them.
    > >
    > > Allison
    > >
    > >

    > If you don't need the large screen of a laptop, a simple serial
    > terminal can
    > be a Palm Pilot. Any of the older models with the serial hot sync
    > connector
    > works fine. I have modified some of them with a short pigtail
    > soldered to
    > the connector fingers and a DB-9 connector. The original connection
    > was
    > terrible. I use them as test sets. The CASL software development
    > environment allows one to do GUI if wanted. A terminal emulator does
    > fine
    > if you don't need GUI.
    >
    > Don


    Lots of good ideas here - thanks much. I will try my palmpilot and see
    how that looks.

    What I was thinking of is along the lines of the ezvid and ezdisplay
    offered by Multilabs http://www.multilabs.net that has serial input
    and outputs to ntsc video or an lcd display. Their card does not seem
    to support as many columns and rows of characters, but I think that
    will give you an idea.

    Thanks Hal, for the description of the yasbec notebook display.

    tnx to all,
    john

    --


+ Reply to Thread