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electron.c: added PCB layout

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Guru 2015-10-12 07:38:32 +08:00
parent ed5fa13042
commit 43c85d594d
1 changed files with 47 additions and 6 deletions
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53
src/mame/drivers/electron.c
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@ -1,12 +1,54 @@
// license:BSD-3-Clause
// copyright-holders:Wilbert Pol
/******************************************************************************
Acorn Electron driver
MESS Driver By:
Wilbert Pol
Acorn Electron driver
By Wilbert Pol
Hardware Overview
-----------------
The Acorn Electron is a budget version of the BBC Micro home computer
Basic specs are:
6502 CPU @ 2MHz or 1MHz
32k RAM and 32k ROM
Text modes: 20x32, 40x25, 40x32, 80x25, 80x32
Graphics modes: 160x256 (4 or 16 colors), 320x256 (2 or 4 colors), 640x256 (2 colors), 320x200 (2 colors), 640x200 (2 colors)
Colors: 8 colors (either solid or flashing)
Sound: 1 channel, 7 octaves; built-in speaker
Internal ports for cassette storage, RGB/CVBS monitors and TV output
Various expansions can be added via the rear expansion port
PCB Layout
---------- |-------------------|
|--------| EXPANSION PORT |
|-----|---------------------| |---||---------|
|MOD | SPKR 16MHz LS169 18VAC|| []18VAC INPUT
| |17.7345MHz ROM 18VAC|| POWER |
|-----| 74S04 |----| || SUPPLY |
| KBD_CONN 6502 |ULA | || |
|CVBS |----| || +5VDC |
|RGB LS00 LS86 || -5VDC |
| PWR|| |
|CASS LM324 LS00 LS86 S74 LS74 4164 4164 4164 4164 || |
|------------------------------------------------------------||---------|
Notes: (all IC's shown. Only 16 ICs are used)
6502 - 6502 CPU, clock input 2.000MHz [16/8]
ULA - Custom logic chip 12CO21, also containing most of the BBC Micro circuitry
Early PCB revisions used a PLCC68 chip in a socket. Later revisions used a
PGA68 chip soldered directly into the motherboard
4164 - 4164 64k x4-bit DRAM (4 chips for 32kbytes total)
ROM - Hitachi HN613256 32k x8-bit MASK ROM containing OS & BASIC
LM324 - Texas Instruments LM324 Operational Amplifier
MOD - UHF TV modulator UM1233-E36
CVBS - Composite color video output socket
RGB - RGB monitor video output socket
CASS - Cassette port
PWR - 3-pin power input from internal power supply
KBD_CONN - 22-pin keyboard connector
SPKR - 2-pin internal speaker connector
******************************************************************************
Emulation notes:
I don't have a real system to verify the behaviour of the emulation. The things
that can be done through BASIC programs seem to behave properly (most of the time :).
@ -23,7 +65,6 @@ Missing:
- Support for floppy disks
- Other peripherals
- Keyboard is missing the 'Break' key
******************************************************************************/
#include "emu.h"