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Arnold V specs

5,084 bytes added, 09:43, 28 November 2006
The old CPC6128 keyboard is used, except that the colour scheme has been changed and the connecting cable exits in a different location.
 
Unlike the existing CPC range, the size of dynamic RAM and whether or not a disk drive is installed are separately configurable options. It is therefore possible to produce a "4128" (128k diskless) or "664" (64k with disk) variant. Also, it is possible to increase the number of analogue input channels to eight.
 
The following new features are provided by change to the ASIC and the main PCB electronics:
 
===Hardware Sprites===
All sprite characteristics are independent of the main screen mode, the unmagnified pixel size being as for screen mode 2 (640x200). Sprite colours are defined by 15 entries in the colour palette (see section 2.2 below). Thus sprites can be in different colours and resolutions from the rest of the screen. Sprites may overlay with each other or the border, and are prioritized so that the border has the highest priority, followed by sprites 0 to 15 in sequence, then the main screen data. Thus sprites always appear "in front of" the main screen and behind "the border".
 
===Colour palette===
10-1F border colour</pre>
 
===Split Screen facility===
The exact timing is based on 1us cycles as follows. After the leading edge from HSYN from the 6845 there is one dead cycle followed by an instruction fetch cycle for each channel which is active (i.e. enabled and not paused). The execute cycles then follow for each active channel. All instructions execute in one cycle, except that LOAD requires at least 8 cycles. An extra cycle is added to a LOAD if the CPU is accessing the 8255, or two extra cycles if the CPU access was itself a PSG register write.
 
===Interrupt service===
The two ROM disable bits in the existing mode and ROM enable register disable the ROM as before, wherever it is mapped, as does the ROMDIS signal from the expansion bus.
The "write through" mechanism, whereby writes to an area which is currently mapped as ROM actually write to the underlying RAM, still functions, wherever the ROM is mapped. However the write through mechanism cannot be used to access the register page. Write through also does not operate to the RAM from the register page.
 
===Analogue paddle ports===
The ASIC includes the logic for an octal A/D converter, in conjunction with an external R-2R network, comparator and analogue multiplexer. Eight analogue input channels are thus available on the PCB, of which only four have connectors. This allows support for four paddles or two joysticks, with capacity for twice this many without redesigning the ASIC. The A/D is 6 bits wide, to give sufficient resolution after calibrating joysticks. It appears to the software as a bank of eight, 6 bit, read-only registers from 6808h to 680Fh, known as ADC0-7. They are updated approximately 200 times per second. The A/D inputs have an input range of 0V (data = 00) to 2.5V (data = 3Fh), and an input impedance of 180k to Vcc.
 
The main oscillator for the ASIC is 40MHz. A divide by 9 output at 4.444MHz is provided with a 5:4 mark/space ratio. It is possible to change the main crystal to 9 x 4.33619MHz = 39.90257 MHz, slowing the whole system by 0.25%. This may or may not upset the disk drives, but even if this is the case, a diskless unit could provide PAL subcarrier frequency locked to the master oscillator, thus improving the picture quality.
 
The ASIC can provide support for eight bit printers. If a link on the PCB is made, the most significant printer port bit will be controlled by bit 3 in register 12 (decimal) of the 6845, i.e. bit 11 of the start address register. If the link is not made, the most significant printer port bit will always be low.
 
The main PCB, disk drive (6128) and cassette mechanism (464) will be mounted to the lower cabinet.
Ideally, the keyboard should be similarly mounted on the lower cabinet, to improve serviceability, as should as many minor components as possible. A slimmer cassette mechanism must be used, to keep the height of the computer low. The cassette mechanism electronics will be mounted below the cassette deck, as with the old version.
 
 
==DISPLAY DEVICES==
The relevant safety standard for this product is BS415 (IEC65).
 
===MONITORS===
The monitors also incorporate stereo speakers, amplifiers, and a volume control. There is no 12V D.C. output.
 
===Modulator/Power Supply units===
The input circuit of the Peritel adaptor will probably need to be redesigned to handle the new analogue video signals. It should also have the sound channels added.
 
 
==NATIONAL VARIANTS==
There will be different versions of the keyboard, instruction book, and disk, as well as the ROM cartridge. It is thus possible to change between, variants without dismantling the computer.
 
*Polystyrene foam packing pieces
*The MM12 or CM14 monitor
 
 
 
==APPENDIX 1==
 
===New Register Map===
 
The new register page, from 4000h to 7FFFh appears as follows:
<pre>
ADDR SIZE POR TYPE MNEM USE
 
4000h 100H N R/W Sprite 0 image data
4100h 100h N R/W Sprite 1 image data
| | | | | |
4F00h 100h N R/W Sprite 15 image data
 
5000h (unused)
 
6000h 2 N R/W X0 Sprite 0 X position
6002h 2 N R/W Y0 Sprite 0 Y position
6004h 1 Y W M0 Sprite 0 magnification
6005h 3 (unused)
6008h 2 N R/W X1 Sprite 1 X position
600Ah 2 N R/W Y1 Sprite 1 Y position
600Ch 1 Y W M1 Sprite 1 magnification
600Dh 3 (unused)
| | | | | |
6078h 2 N R/W X15 Sprite 15 X position
607Ah 2 N R/W Y15 Sprite 15 Y position
607Ch 1 N W M15 Sprite 15 magnification
607Dh 3 (unused)
6080h (unused)
 
6400h 2 N R/W Colour palette, pen 0
6402h 2 N R/W Colour palette, pen 1
| | | | | |
641Eh 2 N R/W Colour palette, pen 15
6420h 2 N R/W Colour palette, border
6422h 2 N R/W Colour palette, sprite colour 1
6424h 2 N R/W Colour palette, sprite colour 2
| | | | | |
643Eh 2 N R/W Colour palette, sprite colour 15
6440h (unused)
 
6800h 1 Y W PRI Programmable raster interrupt scan line
6801h 1 Y W SPLT Screen split scan line
6802h 2 N W SSA Screen split secondary start address
6804h 1 Y W SSCR Soft scroll control register
 
6805h (unused)
 
 
 
 
 
 
 
ADDR SIZE POR TYPE MNEM USE
 
6808h 1 R ADC0 Analogue input channel 0
6809h 1 R ADC1 Analogue input channel 1
680Ah 1 R ADC2 Analogue input channel 2
680Bh 1 R ADC3 Analogue input channel 3
680Ch 1 R ADC4 Analogue input channel 4
680Dh 1 R ADC5 Analogue input channel 5
680Eh 1 R ADC6 Analogue input channel 6
680Fh 1 R ADC7 Analogue input channel 7
6810h (unused)
6C00h 2 N W SAR0 "DMA" channel 0 address pointer
6C02h 1 N W PPR0 "DMA" channel 0 pause prescaler
6C03h 1 (unused)
6C04h 2 N W SAR1 "DMA" channel 1 address pointer
6C06h 1 N W PPR1 "DMA" channel 1 pause prescaler
6C07h 1 (unused)
6C08h 2 N W SAR2 "DMA" channel 2 address pointer
6C0Ah 1 N W PPR2 "DMA" channel 2 pause prescaler
6C0Bh 4 (unused)
6C0Fh 1 Y R/W DCSR "DMA" control/status register</pre
 
 
Registers in I/O space are generally identical to earlier CPC464/6128 versions, except as follows:
<pre> ADDR DATA POR TYPE MNEM USE
 
7Fxxh 00xxxxxx N W Palette pointer register
7Fxxh 01xxxxxx N W Palette memory
7Fxxh 100xxxxx Y W MRER Mode and ROM enable register
7Fxxh 101xxxxx Y W RMR2 Secondary ROM mapping register
7Fxxh 11xxxxxx Y W Memory mapping register (RAM)
DFxxh xxxxxxxx Y W Expansion/Cartridge ROM select</pre>
 
Note that RMR2 can only be accessed when the new feature lock (Section 2.11 above) has been "opened". Otherwise, MRER exists in its place.
 
POR column indicates whether a register has power on reset. A "N" indicates that the contents of a register are undefined at power on.
 
 
 
==APPENDIX II==
 
 
Connector pinouts
 
From front of left hand side rearwards, then along the rear panel towards the right, the connectors are:
 
 
SOUND: 3.5mm stereo jack
<pre>
1 (Shield) GND
2 (Tip) L Sound
3 (Ring) R Sound
</pre>
JOYSTICK 1: 9 way male D. Joystick 2 can be daisy chained
<pre>
1 Up 6 Fire 2
2 Down 7 Fire 1
3 Left 8 Common
4 Right 9 Common (joystick 2)
5 N.C.
</pre>
JOYSTICK 2: 9 way male D.
<pre>
1 Up 6 Fire 2
2 Down 7 Fire 1
3 Left 8 Common
4 Right 9 N.C.
5 N.C.
</pre>
ANALOGUE: 15 way female D
<pre>
1 GND (Pot common) 9 GND (Pot common)
2 Fire 1 10 Fire 1
3 X1 11 X2
4 COM1 (switches) 12 COM2 (switches)
5 +5V 13 Y2
6 Y1 14 Fire 2
7 Fire 2 15 GND (Pot common)
8 GND (Pot common)
</pre>
AUX: 6 pin RJ-11 type
<pre>
1 +5V
2 Common
3 LPEN
4 Fire 2
5 Fire 1
6 GND</pre>
 
 
PRINTER: 25 way female D
<pre>
1 *Strobe 14
2 D0 15
3 D1 16 +5V
4 D2 17 GND
5 D3 18 GND
6 D4 19 GND
7 D5 20 GND
8 D6 21 GND
9 D7 22 GND 10
10 ???? 23 GND
11 BUSY 24 GND
12 25 GND 13</pre>
 
EXPANSION: 50 way Delta range.
<pre>
1 Sound 2 GND
3 A15 4 A14
5 A13 6 A12
7 A11 8 A10
9 A9 10 A8
11 A7 12 A6
13 A5 14 A4
15 A3 16 A2
17 A1 18 A0
19 D7 20 D6
21 D5 22 D4
23 D3 24 D2
25 D1 26 D0
27 VCC 28 *MREQ
29 *M1 30 *RFSH
31 *IORQ 32 *RD
33 *WR 34 *HALT
35 *INT 36 *NMI
37 *BUSRQ 38 *BUSAK
39 READY 40 *BRST
41 *RSET 42 *ROMEN
43 ROMDIS 44 *RAMRD
45 RAMDIS 46 CURSOR
47 LPEN 48 *EXP
49 GND 50 CLK4</pre>
 
MONITOR: 8 way DIN type A (45326)
<pre>
1 *Sync
2 Green
3 Lum
4 Red
5 Blue
6 L Sound
7 R Sound
8 GND
5 V DC: 6mm power</pre>
 
Centre +5V
<pre>
1 N.C. 1 Y1
2 X1 2 Y2
3 X2 3 Y3
4 X3 4 Y4
5 X4 5 Y5
6 X5 6 Y6
7 X6 7 Y7
8 X7 8 Y8
9 X8 9 Y9
10 N.C. 10 Y10</pre>
 
POWER SWITCH: 2 pin 0.1" pitch header
<pre>
1 Input from PSU
2 +5V to Computer</pre>
 
POWER ON LED: 2 pin 0.1" pitch header
<pre?
1 LED Anode
2 GND</pre>
 
ROM CARTRIDGE: 2 pcs 2 x 9 way 2.5mm pitch sockets.
<pre>
1a A10 2a A2 1b +5V 2b +5V
3a *CE 4a A1 3b CLK 4b CA18
5a D7 6a A0 5b CA16 6b CA17
7a D6 8a D0 7b CA15 8b CA14
9a D5 10a D1 9b A12 10b A13
11a D4 12a D2 11b A7 12b A8
13a D3 14a SIN 13b A9 14b A9
15a CCLR 16a GND 15b A5 16b A11
17a GND 18a GND 17b A4 18b A3</pre>
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