mirror of https://github.com/stella-emu/stella.git
Started work on the controller side of the CompuMate emulation.
git-svn-id: svn://svn.code.sf.net/p/stella/code/trunk@2411 8b62c5a3-ac7e-4cc8-8f21-d9a121418aba
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stephena
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@ -98,6 +98,11 @@ class System;
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by two 20K resistors, then it goes through a hex inverting schmitt trigger to
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square it up. This then runs into bit 7 of portA.
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This code was heavily borrowed from z26, and uses conventions defined
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there. Specifically, IOPortA is treated as a complete uInt8, whereas
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the Stella core actually stores this information in boolean arrays
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addressable by DigitalPin number.
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@author Stephen Anthony & z26 team
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@version $Id$
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*/
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@ -25,46 +25,77 @@
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#include "Event.hxx"
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/**
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The Spectravideo CompuMate SV010 was a home computer expansion for the
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Atari VCS / 2600 video game system.
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Cartridge class used for SpectraVideo CompuMate bankswitched games.
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It consists of a membrane keyboard unit with interface connectors. These
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connectors were placed in the module slot and both controller ports of the
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Atari console. As the user could place the keyboard on the old style VCS
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consoles, the two devices resulted in one compact unit. When using with the
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2600jr console, resulted in a desktop computer look with separated keyboard.
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This is more than just a cartridge mapper - it's also a "computer" add-on.
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There's two 8K EPROMs soldered on top of each other. There's two short
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wires with DB-9's on them which you plug into the two controller ports.
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A 42 or so key membrane keyboard with audio in and audio out, and 2K of RAM.
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The CompuMate was equipped with an audio jack for use with a standard tape
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connector as a possibility of permanent data storage.
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There are 4 4K banks selectable at $1000 - $1FFF, and 2K RAM at
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$1800 - $1FFF (R/W 'line' is available at SWCHA D5, so there's no separate
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read and write ports).
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Bankswitching is done though the controller ports
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INPT0: D7 = CTRL key input (0 on startup / 1 = key pressed)
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INPT1: D7 = always HIGH input (tested at startup)
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INPT2: D7 = always HIGH input (tested at startup)
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INPT3: D7 = SHIFT key input (0 on startup / 1 = key pressed)
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INPT4: D7 = keyboard row 1 input (0 = key pressed)
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INPT5: D7 = keyboard row 3 input (0 = key pressed)
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SWCHA: D7 = tape recorder I/O ?
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D6 = 1 -> increase key collumn (0 to 9)
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D5 = 1 -> reset key collumn to 0 (if D4 = 0)
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D5 = 0 -> enable RAM writing (if D4 = 1)
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D4 = 1 -> map 2K of RAM at $1800 - $1fff
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D3 = keyboard row 4 input (0 = key pressed)
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D2 = keyboard row 2 input (0 = key pressed)
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SWCHA: D7 = Audio input from tape player
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D6 = Audio out to tape player and 4017 CLK
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1 -> increase key column (0 to 9)
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D5 = 4017 RST, and RAM direction. (high = write, low = read)
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1 -> reset key column to 0 (if D4 = 0)
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0 -> enable RAM writing (if D4 = 1)
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D4 = RAM enable: 1 = disable RAM, 0 = enable RAM
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D3 = keyboard row 1 input (0 = key pressed)
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D2 = keyboard row 1 input (0 = key pressed)
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D1 = bank select high bit
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D0 = bank select low bit
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Keyboard column numbering:
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column 0 = 7 U J M
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column 1 = 6 Y H N
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column 2 = 8 I K ,
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column 3 = 2 W S X
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column 4 = 3 E D C
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column 5 = 0 P ENTER SPACE
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column 6 = 9 O L .
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column 7 = 5 T G B
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column 8 = 1 Q A Z
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column 9 = 4 R F V
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INPT0: D7 = CTRL key input (0 on startup / 1 = key pressed)
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INPT1: D7 = always HIGH input (pulled high thru 20K resistor)
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INPT2: D7 = always HIGH input (pulled high thru 20K resistor)
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INPT3: D7 = SHIFT key input (0 on startup / 1 = key pressed)
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INPT4: D7 = keyboard row 0 input (0 = key pressed)
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INPT5: D7 = keyboard row 2 input (0 = key pressed)
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The keyboard's composed of a 4017 1 of 10 counter, driving the 10 columns of
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the keyboard. It has 4 rows. The 4 row outputs are buffered by inverters.
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Bit 5 of portA controls the reset line on the 4017. Pulling it high will reset
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scanning to column 0. Pulling it low will allow the counter to be clocked.
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Bit 6 of portA clocks the 4017. Each rising edge advances the column one
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count.
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There's 10 columns labelled 0-9, and 4 rows, labelled 0-3.
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Column
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0 1 2 3 4 5 6 7 8 9
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+---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+
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| 7 | | 6 | | 8 | | 2 | | 3 | | 0 | | 9 | | 5 | | 1 | | 4 | 0
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+---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+
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+---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+
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| U | | Y | | I | | W | | E | | P | | O | | T | | Q | | R | 1
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+---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ Row
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+---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+
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| J | | H | | K | | S | | D | |ent| | L | | G | | A | | F | 2
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+---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+
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+---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+
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| M | | N | | < | | X | | C | |spc| | > | | B | | Z | | V | 3
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+---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+ +---+
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Function and Shift are separate keys that are read by 2 of the paddle inputs.
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These two buttons pull the specific paddle input low when pressed.
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Because the inputs are inverted, a low indicates a pressed button, and a high
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is an unpressed one.
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The audio input/output are designed to drive a tape player. The audio output is
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buffered through an inverter and 2 resistors and a capacitor to reduce the level
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to feed it into the tape player.
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The audio input is passed through a .1uf capacitor and is pulled to 1/2 supply
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by two 20K resistors, then it goes through a hex inverting schmitt trigger to
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square it up. This then runs into bit 7 of portA.
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This code was heavily borrowed from z26, and uses conventions defined
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there. Specifically, IOPortA is treated as a complete uInt8, whereas
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