Author Topic: z80-like portable computer for <$30! (If you build one) (Read 54027 times)

Keoni29 · « **Reply #135 on:** February 26, 2014, 03:27:04 pm »

Working on a midi player program for the eZ8. This morning I found out that the midi file format is not as complicated as I thought. It is just a stream of midi events.

Research:

I will be using the second UART for midi out. I have a little module for my electronic drum set that has all of the standard midi sounds in it, so I will be using that to generate the sounds!

Streetwalrus · « **Reply #136 on:** February 26, 2014, 04:06:17 pm »

That does sound cool.

Thouh it would be more retro like if you used one of those C64 SIDs you have.

Keoni29 · « **Reply #137 on:** February 26, 2014, 04:42:15 pm »

Good thing I came prepared: http://ourl.ca/20468

Streetwalrus · « **Reply #138 on:** February 26, 2014, 04:57:39 pm »

Wait are you using this ? I got slightly confused and thought you didn't.

Keoni29 · « **Reply #139 on:** February 26, 2014, 06:25:21 pm »

I can use both because you can daisy chain midi devices.

Streetwalrus · « **Reply #140 on:** February 26, 2014, 06:31:33 pm »

Oh that's cool.

Keoni29 · « **Reply #141 on:** February 27, 2014, 04:46:34 am »

YES! I finally managed to get the midi output working. What I was doing wrong before was that I sent a midi parameter that was 8 bits long instead of 7 bits. This caused some issues.

Now I am going to work on a midi player! I need to figure out a way to time it first. I was thinking about using the vblank interrupt that the gameduino can provide.

Keoni29 · « **Reply #142 on:** February 27, 2014, 04:01:08 pm »

New features:
-Improved hex monitor
-Syscall vector table
-Midi!
-Random improvements to the code
-Blinking cursor

I am also re-doing most of the comments. Example:
;=================================================================================================== ; S Y S C A L L V E C T O R T A B L E ;=================================================================================================== org 0800h ;0800h : I/O operations ---------------------------------------------------------------------------- dw putc ;+0 dw puts ;+2 dw puts_r ;+4 dw putFd ;+6 dw puti ;+8 dw puth ;+10 dw 0,0,0,0,0,0,0,0,0,0 ;(reserved) dw spi_transfer ;+30 dw spi_transfer_buffer ;+32 dw 0,0,0,0,0,0,0,0 ;(reserved) dw midiout ;+48 dw 0,0,0,0,0 ;(reserved) ;0840h : Memory operations ------------------------------------------------------------------------- dw F_unlock ;+0 dw F_erase_page ;+2 dw 0,0,0,0,0,0,0,0,0,0,0,0,0,0 ;(reserved) ;0850h : Video operations -------------------------------------------------------------------------- dw gd_cpy ;+0 dw gd_copy ;+2 dw gd_fillmeup ;+4 dw gd_char_pal ;+6 dw 0,0,0,0,0,0,0,0,0,0,0,0 ;(reserved) ;0860h : Math routines ----------------------------------------------------------------------------- dw div_8 ;+0 dw 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 ;(reserved)

Streetwalrus · « **Reply #143 on:** February 27, 2014, 06:04:54 pm »

Kewl to see this progress.

Keoni29 · « **Reply #144 on:** February 28, 2014, 01:37:18 pm »

I am working on a header file that contains all the data you need to develop software for the operating system.

This sample program uses the syscall: puts (print text on screen/terminal)
;=================================================================================== ; M E S S A G E B O X ; eZ8 OS sample program ; ; Description: ; Draws a box on screen ; Upcoming features: ; - Custom text in the box ;=================================================================================== include "eZ8OS.inc" prg_org(14) ;Program resides in page 14 of file memory prg_message: push cr_x push cr_y ld cr_x,#30 ld cr_y,#15 str_out(str_box_h) scrolldown str_out(str_box_v) scrolldown str_out(str_box_v) scrolldown str_out(str_box_h) pop cr_y pop cr_x ret ;=================================================================================== ; D A T A A R E A ;=================================================================================== str_box_h: asciz "+----------------+" str_box_v: asciz "| |" ;=================================================================================== ; M A C R O'S ;=================================================================================== str_out MACRO str ld R0,#HIGH(str) ld R1,#LOW(str) syscall puts ENDMAC str_out scrolldown MACRO ld cr_x,#30 inc cr_y ENDMAC ;-----------------------------------------------------------------------------------

Keoni29 · « **Reply #145 on:** March 03, 2014, 04:32:47 am »

The eZ8 computer plays back MIDI files now!!!

TIfanx1999 · « **Reply #146 on:** March 03, 2014, 04:57:23 am »

That's awesome!

Keoni29 · « **Reply #147 on:** March 06, 2014, 03:18:06 pm »

Added a userport. It has 3.3v, 5v, 8IO pins and serial rx tx
The serial tx signal is shifted up from 3.3v to 5v so it can be used for stuff like midi.

Keoni29 · « **Reply #148 on:** March 07, 2014, 03:46:31 pm »

I just hooked up the keyboard to the new board I made. Now I do not have to use the psion pocket computer for input anymore. This frees up the serial port for sending and receiving files from my pc.

The midi files take up a lot of space in flash memory. I can barely fit 3 midi files on the internal flash. That's why I need to include some external memory into the eZ8 computer. I was thinking about using one of these 128Mbit flash roms: http://nl.farnell.com/spansion/s25fl127sabmfi101/memory-flash-128mbit-8soic/dp/2328002
I can store about 300-400 midi files on this chip!

Keoni29 · « **Reply #149 on:** March 14, 2014, 03:46:12 am »

I just ordered the memory. It will probably take a little while before it gets shipped to me, so that gives me some time to think about the extended filesystem. Because I made file headers variable-sized I can add things like extended addresses. Only the first block has an extended address, so the other blocks in the file cannot exceed a sector of 64KB. I might add something to work around that. The lower byte in the 'next_block_address' field of the block header is there just so the filesystem won't get confused. It is not actually used at the moment. I could use it to indicate that the file continues in a different 64KB sector.

Author Topic: z80-like portable computer for <$30! (If you build one) (Read 54027 times)

Keoni29

Re: z80-like portable computer for <$30! (If you build one)

Streetwalrus

Re: z80-like portable computer for <$30! (If you build one)

Keoni29

Re: z80-like portable computer for <$30! (If you build one)

Streetwalrus

Re: z80-like portable computer for <$30! (If you build one)

Keoni29

Re: z80-like portable computer for <$30! (If you build one)

Streetwalrus

Re: z80-like portable computer for <$30! (If you build one)

Keoni29

Re: z80-like portable computer for <$30! (If you build one)

Keoni29

Re: z80-like portable computer for <$30! (If you build one)

Streetwalrus

Re: z80-like portable computer for <$30! (If you build one)

Keoni29

Re: z80-like portable computer for <$30! (If you build one)

Keoni29

Re: z80-like portable computer for <$30! (If you build one)

TIfanx1999

Re: z80-like portable computer for <$30! (If you build one)

Keoni29

Re: z80-like portable computer for <$30! (If you build one)

Keoni29

Re: z80-like portable computer for <$30! (If you build one)

Keoni29

Re: z80-like portable computer for <$30! (If you build one)