Changes
/* Effort done */
You can power Amstrad CPC using extension port, applying 5v. By doing it, power down button of Amstrad doesn’t run. Using this way you reach a common 5v power between starter-kit and Amstrad. I connected wires from extension port directly to FPGA, as they are used just for listening.
=== DONE : ROM and RAM extension ===
In r004, you have more RAM +512KB, and you can add ROMs.
In r005.4, I add another UpperROM set : .f00 to .fFF file extension (hexa). If you press "space" during a reset_key ("page up" key), upperROM files used range from .f00 to .fFF instead of ranging from .e00 to .eFF. LowerROM .eZZ file extension is still used in both case.
=== Sound output ===
==== PWM ====
Using a simple PWM, data is entered at a certain speed, the PWM clock speed.
If you simulate a constant PWM output signal at middle range of voltage (state just between 0V and 5V : 2.5V), it results an alternance of 0V and 5V, that result in a noise sound. In Arkanoid, this defect make some continues sounds instead of silents...
My idea is generating a sound having a frequency upper that dog ultra sound, while I want to simulate a constant 2.5V.
For this I do use two clocks entries in my PWM : one about data entry, and another about algorithm execution.
This result a high quality sound output (in addition to this nice [http://www.fpgaarcade.com/library.htm Yamaha sound chip from fpgaarcade])
==== Stereo sound output ====
[[File:STarKos1 21 FPGAmstrad_800x600.png|none|STarKos 1.21 running on FPGAmstrad]]
Sound chip was modified in order to get channel A+B at left, and channel B+C at right.
It was tested OK using [http://www.grimware.org/doku.php/documentations/software/starkos/start STarKos 1.21] sound tracker (track "Carpet")
=== DONE: Another disk selector ===
"PRINT INP(&CAFE)" does print current disk selected number.
==== DONE : A advanced dsk drive ====
Done on r004, I added also a second Drive in order to copy easily files from one disk to another.
[http://www.cpcwiki.eu/forum/amstrad-cpc-hardware/fdc-floppy-t80ds-detection/ CPCWiki forum - Amstrad CPC hardware - FDC floppy t80ds detection] : talk about FDC in MiST-board CoreAmstrad.
==== DONE : A advanced FDC (with write access and more) ====
Since r004 "mecashark", the FDC implementation has write access !
==== UNDONE : FAT32 fragmented files support ====
Since advanced FDC, dsk files have to be defragmented. Only ROMs are safe with a not defragemented sdcard...
==== TODO : SNAP DSK ====
Add an option in OSD MENU : "SNAP DSK". Does create a copy of current disk in current drive into "SNAP[number].DSK". Heuristic for number : file count (at boot, incremented at each snap dsk done)
=== TODO : A X/Y input ===
Priority: HIGH! (asked by Markus Hohmann)
==== TODO DONE : move SCART parameter into mist.ini ====
Doing like in other cores : do use the global "scandoubler" option in mist.ini to switch between VGA and TV mode.
In some emulators, keyboard is mapped directly behind PIO.
In original schematic, PIO is the only one component having a low state reset (0), I think that imply a 0 value as state init of internal components variable. Data bus of Z80 seems having a pull-up state (read 1 when nothing is plugged), for example a unplugged ROM does respond xFF in data-bus.
Update : arnoldemu's testbench PPI passed.
=== TODO : Scanline ===
It is also a simple visual effect to enable/disable, making games looking like old CRT monitors.
=== TODO : Monochrome option ===
Add an option to turn screen into green monochrome mode (in mode TV and in mode VGA)
=== TODO : Ethernet ===
