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Messages - Keoni29

Pages: 1 2 3 [4] 5 6 ... 168
46
Other / Re: Visicom Textphone Reverse-engineering
« on: January 17, 2015, 08:12:24 am »
I have been working on a monitor program that allows me to interact with the visicom via serial. I got serial communication and buffering working, but I cannot get string parsing to work because of some weird bug. I am now rewriting the parser.

The monitor will be used for reading and writing from and to memory respectively.
Monitor syntax
- Valid characters are 0-9 and A-F and spaces as separator characters.
- Valid hexadecimal needs to be a multiple of two characters long.

Example of good input:
Code: [Select]
4000 12 3456 AB CD EF

12AB65cd33 6692aB
Example of bad input & punishment:
Code: [Select]
Hello
?
help
?
h
?
:q!
?
001 55 Ab
?
0001 55 Ab C
?
???????
?
MAKE IT STOP
?

Source can be found on my github page: http://github.com/keoni29/visicom

47
TI-Nspire / Re: nGL - a fast (enough) 3D engine for the nspire
« on: January 17, 2015, 07:55:14 am »
Congrats on the POTY. I have not checked on this project in a while and I must say that I am really pleased with the progress you made. Great work :D

48
Art / Re: Mockups "please say this is going to be a game"
« on: January 17, 2015, 07:50:08 am »
that is nice. try decreasing the contrast on the background, though. right now it's difficult to tell the sprites apart from the map.
Yes definitely, but other than that I really like the way they turned out. Keep on spriting :D

49
News / Re: More information on the TI-84 Plus CE
« on: January 17, 2015, 07:48:42 am »
I am personally very exited about the eZ80. They finally listened to us :) The hardware looks pretty straightforward: you got your ASIC with the cpu ram and link assist in it, your screen and some passives to blend it all together. As opposed to the CSE this is not a TI84+ with a color screen slapped on. It's its own thing. With that said I hope it is backward compatible with programs written for the CSE e.g. tiboy, steins gate, portal and all the other amazing software releases from the past two years.

There is one concern I have with this new cpu: is the LCD fast enough to keep up with the cpu or will we have to introduce wait-cycles again just like with the monochrome lcd? This is not the end of the world, but it would be a considerable bottleneck for graphics-intensive applications.

50
Art / Re: Mockups "please say this is going to be a game"
« on: January 12, 2015, 01:49:23 pm »
What is this palette? It looks really nice :D

51
Other / Visicom Textphone Reverse-engineering
« on: January 11, 2015, 12:50:53 pm »
Project page: http://8times8.eeems.me:81/project/software/visicom/

The Visicom is a textphone for deaf people from the 80's. It has a keyboard, video output and built in modem. You could use it as a textphone using the textphone protocol or as a teletype (tty) using the built in modem.

I bought this at a thriftshop because it looked interesting.
I decided to crack it open and find out exactly what makes it tick. Detailed documentation can be found on my project page.


Guts

Left: Video output. You're greeted with a dutch menu. This image shows B&W video, but there is a switch inside the device which enables 8 color video.
Right: Rom reader device I built to dump the firmware. The disassembly can be found here: http://8times8.eeems.me:81/project/software/visicom/disassembly.php

I found an open-source disassembler written in Golang for the tms7001 microcontroller that is inside the visicom, but it was really buggy. I managed to fix a lot of the bugs. I published the disassembled rom on my website. Using javascript I made all addresses operands links so you can jump by clicking them.
Rom disassembly can be found here: http://8times8.eeems.me:81/project/software/visicom/#h2

I am now able to write my own code for the device. So far I can:
- Set up the serial clock generator.
- Control the MCU's internal I/O port.
- Use interrupts
- Read and write data over serial (using the ACIA)
- Read keystrokes from the keyboard

I solved some interrupt problems by looking at the disassembly. It seems like the people who designed this thing ran into the same problems as I did :P
Next I want to output characters on the screen.


52
Other / Re: Arduino Computer
« on: January 07, 2015, 05:37:10 pm »
Hmm upon closer inspection it's probably best if I re-wrote this thing some day :P

53
Other / Re: Arduino Computer
« on: January 07, 2015, 03:50:08 pm »
I wrote a brainfuck interpreter and code editor for the arduino. It works with 3 buttons and it is pretty basic, but perhaps you can make use of it. You'd have to modify it to work with a character display.

54
TI Z80 / Re: Hero Core - World Editor
« on: January 02, 2015, 04:03:07 pm »
Core Editor
Up until this point I was using Gamemaker's built-in level editor for creating the Hero Core world. I did not like that editor, so I decided to make my own.
The result was a tool called Core Editor (short cedit.)

I want users to create worlds of their own for others to explore. The editor is open-source, but it is not finished yet.
You can check it out for yourself here: http://github.com/keoni29/cedit

The editor is to be fully customizable from the command line. I have not tried to compile it for windows yet, but it's supposed to be cross-platform.



Features:
- SDL graphics
- Grid
- Scrolling
- Tileset sheets
- Auto-load & save on program startup/end respectively

55
Super Smash Bros. Open / Re: [Axe] Super Smash Bros. Open
« on: December 27, 2014, 03:19:11 pm »
That metanight looks pretty sweet.

56
Other / Re: CBS6000 - an 8-bit 6510 computer
« on: December 26, 2014, 11:32:37 am »
I made a debug routine. It's an interrupt service routine that prints human readable info about the CPU state.
Sample output:
Code: [Select]
A=03,X=08,Y=00,P=34,S=FB,PC=0240It can be called using a brk instruction or by pulling the IRQ pin low. I want to change this to the NMI because I still want to be able to use interrupts.
I want to make it elaborate on the status flags. It will explain what every flag does like so:
Code: [Select]
Negative number, BRK, INT disabled, Decimal mode enabled
https://raw.githubusercontent.com/keoni29/cbs6000/master/src/main/debug.asm

57
Humour and Jokes / Re: Important life algorithms
« on: December 24, 2014, 05:32:01 pm »
Code: [Select]
while(oreo)
    oreo--;
Looking though this again, you could optimize:
Code: [Select]
while(oreo--);
I think the compiler does that for you.

In both cases the outcome is:
while:
branch if oreo is zero: endwhile
oreo --
branch to while
endwhile:

58
Other / Re: CBS6000 - an 8-bit 6510 computer
« on: December 24, 2014, 07:11:39 am »
Original post:
http://8times8.eeems.me:81/blog/?thread=12

Muhahahahahaha
The cbs6000 is making some noise! I hooked up a digital to analog converter to the serial port and wrote some software that plays back sound data in ram. Almost the entire first 64k bank is filled up for about 5 seconds worth of 8000 bytes/sec 8 bit audio.

59
TI Z80 / Re: [Axe] Axagon
« on: December 23, 2014, 07:36:46 am »
I volunteer for beta testing :3

60
TI-Nspire / Re: Portal Nspire
« on: December 23, 2014, 04:15:41 am »
Can you shoot portals in 4, 8 or infinite directions?

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