|#FB7E||%xxxxx0x1 0xxxxxx0||[[765 FDC]] (internal) Status Register||Read|| -
|-
|#FB7F||%xxxxx0x1 0xxxxxx1||[[765 FDC]] (internal) Data Register||Read||Write
|}
== Ext Port ==
{|{{Prettytable|width: 700px; font-size: 2em;}}
|''bit''||Action
|-
|7||not used
|-
|6||not used
|-
|5||if 0, then AY is accessed when read/write to 8255 port A, if 1 then real-time clock is accessed with read/write to 8255 port A. When real-time clock is selected, bits 2..0 of PPI port C are used to define real-time clock operation. DS bit 2, AS bit 1, R/W bit 0. So combinations are 2, write address, 4 write data, 5 read data.
|-
|4||Enable 8253 timer. Any I/O write then accesses 8253 with data comming from 8255 port A. Bit A0/A1 of I/O port defines 8253 register
|-
|3||force video to black
|-
|2||MAPMOD
* When MAPMOD=0: Uses CPC-style 27-color palette, and CPC6128-style RAM banking
* When MAPMOD=1: Uses special 64-color palette, and extended RAM mapper
|-
|1||Enables high resolution in X. Also changes some clock frequences. Controls decoding of video address.
|-
|0||Not fully understood yet. Controls decoding of video address
Aleste "Gate Array" is similar in functionality to the Gate-Array in the CPC/Plus.
{|{{Prettytable|width: 700px; font-size: 2em;}}
|''bit 7''||''bit 6''||Action
|-
|0||0||Gate Array Register 0 - Pen index write
|-
|0||1||Gate Array Register 1 - Pen ink write
|-
|1||0||Gate Array Register 2 - Mode, Rom enable, Leds
|-
|1||1||Gate Array Register 3 - Used by mapper
|-
|}
=== Gate Array Register 0 ===
Pen index:
{|{{Prettytable|width: 700px; font-size: 2em;}}
|''bit''||Action
|-
|7||0
|-
|6||0
|-
|5||not used
|-
|4||If set to 1, border is selected
|-
|3..0||Pen index
|}
=== Gate Array Register 1 ===
The number is converted by IC D62.
* When MAPPER is set in EXTPORT, then the numbers effectively define a R,G,B colour with 2 bits per element, but the rom then changes the order of the bits before it gets to the hardware.
* When MAPPER is not set, the number is equivalent to the CPC's Gate-Array colour value, but this is looked up in IC D62 and converted into a 2-bit per element R,G,B for the aleste video hardware.
=== Gate Array Register 2 ===
{|{{Prettytable|width: 700px; font-size: 2em;}}
|''bit''||Action
|-
|7||0
|-
|6||1
|-
|5||CAPS LED
|-
|4||RUS LED
|-
|3||Upper rom enable/disable
|-
|2||Lower rom enable/disable
|-
|1..0||Mode
|}
bit 0,1 define the mode. The actual resolution is then dependant on bit 1 of EXTPORT.
When HIGHTX is 0, CPC modes are chosen. When HIGHTX is 1, Aleste modes are chosen.
CPC modes:
{|{{Prettytable|width: 700px; font-size: 2em;}}
|''bit 1''||''bit 0''||Mode
|-
|0||0||160x200 (16 colours)
|-
|0||1||320x200 (4 colours)
|-
|1||0||640x200 (2 colours)
|-
|1||1||Don't know. On CPC this is 160x200 (4 colours)
|-
|}
Aleste modes:
{|{{Prettytable|width: 700px; font-size: 2em;}}
|''bit 1''||''bit 0''||Mode
|-
|0||0||Don't know
|-
|0||1||Don't know
|-
|1||0||Don't know
|-
|1||1||Seems to be 320x200 (16 colours)
|-
|}
=== Gate Array Register 3 (in CPC-style MAPMOD=0) ===
Controls RAM Banking, similar to the Gate Array on CPC6128 (or, more specific, similar to the 16L8 PAL IC which assists the CPC6128s Gate Array).
In the Aleste register 3 is effectively Mapper select.
Writing to port #7Fxx with bit 7 and bit 6 of data set to 1 can be used to set page 3 RAM bank in Aleste mapper mode, or to define CPC RAM configuration in CPC mode.
'''Actually''', it seems to work more like an [[Inicron RAM-Box]] (which isn't fully compatible with the dk'tronics style [[Standard Memory Expansions]]).
=== Gate Array Register 3 (in Aleste's special MAPMOD=1) ===
The decoding of the I/O port for the mapper uses bit 15 of the I/O address in the same way as the Aleste "Gate Array".
Bit 9,8 define which page.
To avoid writing to the Aleste "Gate-Array" bits 7 and 6 of the data must be 1.
The remaining bits define the RAM block/configuration to use.
In CPC mode, writing to the mapper changes the RAM configuration for all pages, with the memory configuration being the same as a DK'Tronics compatible RAM.
In Aleste mapper mode, writing to the mapper changes the RAM for one page.
It is not know:
* Must you write to #7Fxx in CPC mode to define RAM configuration or can you also use #7Cxx, #7Dxx, #7Exx for same effect
* When you write CPC RAM configuration is it mirrored in all mapper registers?
== Upper ROM Bank ==
Works like the [[Upper ROM Bank Number]] on CPCs. The banks used for the Aleste BIOS are:
00h BASIC (bytes in 4000h..7FFFh in the Aleste's 64K EPROM)
03h BOOTMENU (bytes in C000h..FFFFh in the Aleste's 64K EPROM)
07h AMSDOS (bytes in 8000h..BFFFh in the Aleste's 64K EPROM)
All other values 01h..02h, 04h..06h, 08h..FFh do select BASIC, too.
== PPI 8255 ==
Works similar to the [[8255]] in the CPC (see there for details). Differences are listed below.
=== PPI Port A (Port F4xxh) ===
{|{{Prettytable|width: 700px; font-size: 2em;}}
|''Bit''||''Description''||''Usage in CPC''||''Usage in Aleste''
|-
|7-0||PSG.DATA||[[PSG]] Databus (Sound/Keyboard/Joystick)||[[PSG]] Databus (Sound/Keyboard/Joystick/Printer), and Baudrate/Future Timer databus, and RTC databus)
|-
|}
=== PPI Port B (Port F5xxh) ===
{|{{Prettytable|width: 700px; font-size: 2em;}}
|''Bit''||''Description''||''Usage in CPC''||''Usage in Aleste''
|-
|7||CAS.IN||Cassette data input||Same as on CPC
|-
|6||PRN.BUSY||Parallel/Printer port ready signal, "1" = not ready, "0" = Ready||Same as on CPC
|-
|5||/EXP||Expansion Port /EXP pin||Wired to GND (uh, BUT, Aleste Expansion Port DOES have an /EXP pin?)
|-
|4||LK4||Screen Refresh Rate ("1"=50Hz, "0"=60Hz)||Same as in CPC
|-
|3||LK3||Manufacturer ID bit3||rowspan=2|LK3 is shortcut to LK2, and wired to a pull-up resistor
|-
|2||LK2||Manufacturer ID bit2
|-
|1||LK1||Manufacturer ID bit1||/DISCINT (the /INT pin from FDC 765)
|-
|0||[[CRTC]] VSYNC||Vertical Sync ("1"=VSYNC active, "0"=VSYNC inactive)||Same as on CPC (though using emulated timings from VDKEY eprom)
|-
|}
=== PPI Port C (Port F6xxh) ===
{|{{Prettytable|width: 700px; font-size: 2em;}}
|''Bit''||''Description''||''Usage in CPC''||''Usage in Aleste''
|-
|7||PSG BDIR||rowspan=2|PSG function selection||rowspan=2|Same as in CPC
|-
|6||PSG BC1
|-
|5||Cassette Write data||Cassette Out (and Printer Bit7, see [[8bit Printer Ports]])||Cassette Out
|-
|4||Cassette Motor Control||Cassette Motor (0=Off, 1=On)||Printer Strobe (0=High, 1=Low)
|-
|3||rowspan=4|Keyboard row||rowspan=4|10 rows (0..9)||rowspan=4|11 rows (0..10), and also used for RTC control signals
|-
|2
|-
|1
|-
|0
|-
|}
=== PPI Control (Port F7xxh) ===
This register has two different functions depending on bit7 of the data written to this register.
See the normal CPCs [[8255]] description for details.
== Keyboard ==
The Aleste uses a MSX keyboard, as seen by the characteristic five function keys. The mainboard contains some excessive TTL logic, assisted by the upper data bits of the VDKEY eprom, that translates the MSX matrix to a CPC matrix.
So, at I/O port level, the CPU "sees" a CPC matrix, not a MSX matrix. When running MSXDOS, this leads to the funny situation that MSXDOS must undo the hardware MSX-to-CPC translation by some software CPC-to-MSX translation.
The keyboard has some additional keys, which aren't on normal CPC keyboards:
* '''F1/F6, F2/F7, F3/F8, F4/F9, F5/F10''' - MSX-style function keys, mapped to keyboard row 10, bits 7,6,5,4,3.
* '''RES''' - Reset button, goes to /RESET signal.
* '''Four unknown keys''' - These keys (above the numeric keypad) may be unused, or having same function as other keys?
The Aleste has a JCUKEN keyboard, rather than a QWERTY keyboard.
* '''Unknown''' if this done by hardware, or by patched CPC bios (?)
* Normally, the key next to TAB '''should''' be Row8.Bit3 in the CPC matrix. And the BIOS should assign "Q" to it for english QWERTY keyboards, "A" for french "AZERTY" keyboards - or "J" for russian JCUKEN keyboards (though not sure if Patisonic has implemented it that way).
The Aleste 520EX is a clone of the Amstrad CPC 6128 developed 1993 Patisonic in Omsk (Siberia). The Aleste is rare, according to Patisonic themselves, they "produced several dozens of the model, some of them was in 'kit' form".
Additionally to the standard CPC6128 features, it includes a number of extra features: 64-color palette, double color depth in slightly decreased horizontal resolution mode (eg. 16 color at 256x200 resolution), battery-backed Real Time Clock chip, 512Kbyte RAM (of which 192K can be accessed as on 64K CPC with 128K dk'tronics memory expansion), 8bit printer port, expanded keyboard matrix with 10 additional keys, two software controlled LEDs, extended Expansion Port (with additional pins for DMA support).
The computer works with Amstrad CP/M and MSXDOS as well (note: MSXDOS is a CP/M clone, which uses a FAT filesystem, as used on MSX and MS-DOS computers, instead of the normal CP/M filesystem).
- Interrupts can't be manually cleared. This was possible on the CPC by writing to the Gate Array with data bit 7 set 1, bit 6 set to 0 and bit 4 set to 1. In the Aleste this bit is controls an LED.
- Decoding of it's equivalent of the Gate-Array is based on A15 only.
- The Aleste uses a patched CPC6128 Operating System ROM. It is patched to use the Aleste's 8-bit printer port and has a different startup message.
Special Mode
At this mode computer have different memory manager. The manager seems same like MSX mapper and could swicth ON any 16KB page of whole memroy at the any of 16KB page of CPU memory.
The mode have different color coding system. It has the color lookup table (CLUT) or another name pallette. That is dual port memory one prot for coversion pixel's color number to RGB levels. But second for CPU acccess. There is 2 bits for each channel at the pallette present, then it lets to have 64 colors.
The mode have two additional modes with 32KB of video memory. Pixel encoding the same as at Amstrad mode but each line has twice more bytes (and pixels). Two 16KB pages transfer to output, one buffer for odd and second even lines of screen.
The computer have also mc146818 compatible RTC and a 8251 compatible serial. A serial mouse can be used.
The 8253 timer is used to generate transmit and receive clock for serial. In addition the CURSOR output of the CRTC is connected as a trigger which is then connected to the colour hardware. So the CRTC cursor can be used to switch colours by the hardware.
Aleste ROM is 64KB:
page 0 is modified Amstrad CPC6128 OS ROM
page 1 is Amstrad BASIC
page 2 is AMSDOS (Amstrad DOS)
page 3 is Boot Rom, BIOS Setup, MSXDOS boot loader
The BIOS SETUP lets control over: date and time, boot drive, RAM disk, screen mode and style, printer, serial port, and mouse.
At the boot time computer loads BIOS and MSXBDOS (BIOS for Disc BIOS) from a bood disc. After that COMMAND.COM (MSXDOS). Computer can bott from RAM disc as well. Computer go to AMSTRAD mode when "Shift" is pressed while reset.
Hardware Expansions
Most pins on the expansion port are the same as on CPC, so most CPC expansions should work on the Aleste (with a 62pin to 50pin adaptor).
Additional Aleste specific expansions are:
External Disc Drive
The Aleste contains a disk controller, so no external disc interface is required. The floppy connector is the same as the "Drive B Connector" on CPC, the only difference is that outputs select signals for two drives (A and B).
The 'official' Aleste drive is 3.5", 720K, 80 tracks. It does also contain the power supply for the computer (which must be connected via whatever separate cable).
Magic Sound Expansion Board
MagicSound is a four channel DMA playback device. Supports 8 bit per sample, 6 bits of volume per channel, and 16bit samplerate timer per channel. Computer uses the board for playing STM (Scream Tracker) files. For details, see:
Another additional board FOTON is a "Light Processor". The board have D54 interface and Aleste with special FX application controls over club's light. (In english: it could be named "Photon Disco Light Controller")
2MB RAM Expansion
The Aleste is said to be expandable to 2MB RAM. Whether or not (and how) this is possible is unclear. There seem to be no provisions for that on the mainboard. The register file (chip number D88) could actually store two additional bank bits. But the I/O port (port 7FFFh with Bit6-7=high) has only ONE spare bit (bit5), so, with that I/O port, only 1MB would be possible, not 2MB.
Turbo Mode Upgrade
Runs the CPU at faster speed. Intended for programs that require a lot of CPU load, like compilers, or ported MSX games (which need to draw the MSX video display processors (VDP) hardware sprites by software).
The Turbo Mode schematic is unknown
Turbo Mode is said to be incompatible with AMSDOS disk access for timing reasons (ie. works only with MSXDOS or so) (not sure if that's a bios/software related problem - it might also be caused by video resolution (which changes CPU and DOT clocks): working in 256/512 pix modes, but not in amstrad-style 160/320/640 pix modes)
VDP Emulator aka GameBIOS
It is not clear exactly what this is.
It seems to describe a collection of software functions (BIOS or library) which aids with converting MSX or MSX2 games to the Aleste.
Certainly the games that have been converted to Aleste are patched, and it seems they do not access any special I/O ports.
It doesn't appear to be an emulator as such, and it seems the Aleste should be modified to run at 8Mhz to run the games at sufficient speed.
Computer have "GameBios" with is emulator of VDP9938. it was sufficiently - to replace the first several kilos-byte of game and MSX2 game worked. Certainly, video processor MSX is by apparatus sharpened for the games, but they worked sufficiently rapidly to 8MGts of game on "alesta" in order in them to play. Game "FireBird" typical
"vertical scroller" worked very well.
The above photos are showing a more or less fully assembled Aleste (the LEDs are missing, and, more important, there is no connection for an internal or external power supply attached to the mainboard - unless the owner used the Expansion Port connector to inject power supply voltages).
