This is a short description of the demo layout, a 68HC11 module which
supports a Toshiba LCD display (160x128 pixels) with a single power supply
of 5V (plus backup if you want).

The board was originally designed as a control unit for some analog
amplifiers. For this reason only a few ports are available at the connectors.

Drop me a line if you need additional information like bootloader...

The scematics are in demo.fig (xfig format)

Component list:
    1k          R8
    10k         R2, R6, R7
    100k        R1, R3
    1M          R5
    4.7k x 8    R9
    10k x 8     R4, R10, R11
    25k         Tr1 (voltage regulator of LCD display)
    50k         Tr2 (selects level of 'low batterie' signal,
                     be careful with range)

    10p         C7, C8
    100n        C6, C10, C12-16
    1u          C11
    4.7u        C1-4, C9, C17-20
    100u        C5

    BC557B      T1, T2
    1N4148      D1

    628128      RAM
    68HC811E2   CPU
    74HCT138    1x8 decoder
    74HCT139    2x4 decoder
    74HCT541    latch
    74HCT573    latch
    RTC62421    real-time clock
    MAX222      serial driver
    MAX667      5V regulator
    MAX680      step-up converter
    MAX691      uP supervisor chip

    LCD         Toshiba LCD TLX-1013-E0 display

    8MHz        crystal

    2x5         2x connector
    2x10        connector
    jumper      J1-3


Address space:
    0x4000-0x4fff      real-time clock A0-A3 select registers
    0x5000-0x5fff      latch, all addresses are equivalent
    0x6000-0x6fff      LCD display;
                       A0==0 data access, A0==1 command access
    0x8000-0xbfff      8kb segment of RAM, segment number is determined
    				   by port PA4-PA6 of CPU

Ports:
    PA0, PA1           unused, pulled up
    PA2                low batterie indicator input
    PA3                on/off switch;
                       write 1 to switch on or 0 (power up default) for off
    PA4-6              segment selector of static RAM
    PA7                beeper output (low active at T2)

    PB0-7              address bus
    PC0-7              address/data bus

    PD0                RS232 receiver
    PD1                RS232 tranceiver
    PD2                RS232 shutdown (==0 for shutdown mode)
    PD3-5              connected to analog connector

    PE0-3              not connected
    PE4-7              connected to analog connector

Jumper:
    J1                 selects between 128kb and 32kb static RAM;
    				   close for 32kb circuits and for some 128kb
    J2,J3              determine operation mode of CPU (see 68HC11 manual);
    				   close both for bootstrap mode,
    				   open both for normal operation
