NB LAPTOP

NB Laptop News.

2016

May 2



I tested both the RS232 with the real Newbrain Machine i manage to load through RS232 port 9 (LOAD#9).
I also tested the TTL interface with the NB Laptop this works ok too.



April 29


Here it is the final SD Card Module.
You can load and save files and there is support for RS232 to connect to a Real Newbrain and use the serial device #9 to load and save files.
All necessary files are at github.


March 11

I uploaded the entire NB Laptop project on Github.
It includes all the schematics, Source code on VHDL for the CPLDs, Assembly code for the z80 bootloader, tools and roms necessary to replicate the NB Laptop.
Also the Arduino code for the SD Card storage module.

https://github.com/cdesp/Newbrain-Laptop.git

March 4

I changed the code and now you can have as many files and directories as you want.
One limitation is that you can not have a directory within a directory at least for now.
Also i added another button STOP. this button Stops the Recording, or Playing of a file (just like the old times) because i do not have a way of knowing when the file is over.
So you press Play and when Newbrain finishes loading you press Stop.
Same for Recording.

The device is working ok on the breadboard. I am waiting for the sdcard module to arrive to put everything in a box with a PCB to connect the lcd, Sd card and RS232.
I am thinking of providing two RS232 interfaces one with 5V signals and one with the real 12V -12V signals (i ll use a MAX235 for this).


March 1

The new SD CARD module for software RS232 communication between NBLaptop and Arduino works ok. I manage to load files that was selected with arduino.



February 28

I made a new device 12 that uses the RS232 module with the 16550.
The Newbrain v24 device 9 that i had to patch in order to have it use the rs232 module is now as it was before the patch.
This software rs232 device i manage to connect with an arduino (softwareserial) but with the addition of CTS/RTS because Newbrain requires these signals.
I also manage to have a SDCARD module connected to the arduino and i ll use this connection to send an receive files to NB Laptop.
Once finished this module will replace Tape 1 as the default store device.

The arduino module has a 16x2 LCD display connect through a serial adaptor to save pins.
As i said it communicates with the SDCARD module to read files and save files.
The module will also have
2 buttons PREV and NEXT to find the desired file.
1 button to "PLAY" the selected file to the NB Laptop.
1 button "REC" to save the file send from NB Laptop.
"PLAY" button will also enter any directories that the user selects.

I have a problem with the available RAM memory on the arduino so for now you can have 20 files or directories each directory can have 20 files (400 files total).



February 14

A new video that shows the 4 graphics modes of the NB Laptop with reverse field.
The program was loaded through the RS232 using LOAD#9 and SAVE#9 from the NB Emulator on the PC.

https://youtu.be/Uvrsb35XG70

January 21

Ok, I fixed the bug with "RS232 receive" so now i can send and receive bytes through comport.

January 18

At last i have a stable tv signal and a working home computer
with the NB ROM version 2.0.

There are some problems with the LCD 16x2 cause i am running the cpu at 4 MHz and the LCD hardware i use works ok up to 2 MHz.
Also when i boot the NB ROM the RS232 Receive does not work ok as i get the wrong byte.
Transmitting works fine.
If i fix the receive bug i could use the rs232 to load programs to the NB Laptop.

You can see a video here that is a demo from the NB Handbook page 88 that uses graphics.
https://www.youtube.com/watch?v=7nUXLKwA4sE 

Still there is work to be done for the screen and the PS/2 keyboard.



2015

July 24

Restarting work on the laptop.
New main PCB installed succesfully.
I have an altera Max epm7160s ready to replace 2 xilinx chips used for the screen display.


New Main PCB


Newbrain laptop with 200 lines graphics screen

February 1

Good news.
Newbrain boots ok
and the PS/2 keyboard is interfacing with the OS.



January 26

I have stabilized everything the computer runs without problems and the data transfer through RS232 is very fast and reliable.
The video is stable enough. only one problem here i have to power the video CPLD with 3.5V instead of 5V as i should in order to have a stable CRT PAL signal. I am working on that, i think is the 16Mhz crystal that causes the problem.
So the TODO List :

1. Test that Newbrain boots ok
2. Interface the new Keyboard device with the Newbrain OS
3. Interface the new RS232 device with the Newbrain OS

2014
August 12

I spent 5 days trying to figure out why my new connections don't work and it was a half burnt Z80 that was causing the problem. I try an old one from a real NB and everything was working ok without changing anything else.

August 3

I experienced strange behavior, glitches and stuff so i dismantled everything and i will reconnect the computer form the start.
I also made another main board PCB with Z80, RAM and ROM connected.


July 23

PS/2 Keyboard can be read at port 70.
Interrupt is raised when a key is available.
I have to translate the PS/2 scan codes to NB Scan code in order for the rom to understand it.

July 15

NB Laptop Hardware booting original NB rom 1.4.

First Boot

July 4

There is a new forum category for the schematics and PCBs i am using so far.

July 1

Signal stabilized a few problems remain though
These are real newbrain video buffers taken from the emulator.

40 chars
80 chars
80 chars 2


June 27

Here are some videos on youtube

40 chars
http://youtu.be/-wjAxnkiWLo

80 chars
http://youtu.be/nUy2k_mx3Qo

Graphics
http://youtu.be/_NGrQRU40HM