My Web Site:
My github: https://github.com/doug-h-rice
This page is powered by http://www.usemod.com/cgi-bin/wiki.pl?UseModWiki/Download
Help can be found at http://www.usemod.com/cgi-bin/wiki.pl?TextFormattingRules
Here were a few other thoughts and scribbles. This page contains some random thoughts not fully thought out.
AutoType Using an Arduino Leonardo and DigiSpark as a keyboard and type.
AT Commands - Serial Using Web Browser - Cloud based IDE still need to upload firmware to devices. Web Browser support serial devices.
Signalling - After a visit or two to the local heritage railways.
WetString - brainstorm ideas about Peer to Peer
I used to have a Science of Cambridge MK14 and a NASCOM 2. Here are some notes.
http://220.127.116.11/acorn/Acorn%20System%20Computers/MK14/mk14.html - site with good documentation.
https://github.com/doug-h-rice My git hub has MK14 emulators that used SDL for the screen and keyboard. There is also a java version. Also a PC version that builds using Tiny C.
My second computer was the NASCOM 2. When I brought it the 8K RAM chips could not be sourced, so it came with a dymanic RAM board. I piggy backed a set of RAM chips on top to double the RAM. I had at least 32K RAM.
I also used a second hand 8 inch floppy brought from Display Electronics and WD1771 floppy disk controller chip. It could only read 80% of the tracks, but once you had command to read write multiple sectors, it was better than a tape. The DOS was a bit of Paper. Later on it was on the disk. I added a 6116 2K memory chip and NiCad Battery to save the code.
I bought a Golfball printer. It could be controlled using the PIO chip. It was controlled using a 2 x 7 solenoids and a busy output. These needed 50 volts. I needed a big thick bit of sorbo rubber to stop the vibrations being heard all around the hall of residence! It took 4 minutes to type a page of A4.
Grant Searle has published some designs for minimal component microprocessor boards that run Microsoft BASIC.
Minimal component Z80,6502,6809 boards are popular. He has an FPGA version.
My Minimal component Z80 emulator system based on Grant's multicomp. https://github.com/doug-h-rice/virtual-multicomp
Grant's website havs spawned many projects
This one is useful. Doug has ported Grants code to many FPGA boards.
It seems to be under a tidy up ( April 2020 )
I remember somebody at the Coventry computer club being enthusiastic about the 6809 in 1979. Here are some notes about getting some assembler code into an FPGA
The emulated CPU communicates with the host using the UART.
This is summarised as a TX and RX register and two flags TxEmpty and RxFull.
Emulated CPU - UART:-
A write to TX resets TxEmpty. A read from RX resets RxFull.
UART - Host:-
A read from TX sets TxEmpty. A write to RX sets RxFull.
If you have a FIFO then there need to be changes.
TxEmpty may need to be TxSpaceAvailable RxFull becomes RxAvailable
Spencer Owen's Z80 system similar to multicomp. https://rc2014.co.uk/
Small Computer Monitor by Stephen C Cousins ( www.scc.me.uk ) Version 1.0.0 configuration R1 for Z80 based RC2014 systems
Version 1.0.0 configuration R1 for Z80 based RC2014 systems
In passing I found these. Raspberry Pi Bare Metal
Running CP/M on a Raspberry Pi Bare Metal.
This is good for old models of the PI that are slow with the later RPi builds.
http://www.dougrice.plus.com/dev/cypress/i2c.c tries to write to the IIC 24LC128. The link may need moving to enable writing to the ROM.
This chip is uses in the logic analysers available from eBay
I was given one of these: https://www.futurlec.com/USBDevBoard.shtml
It has been a challenge to get it to work.
Getting FLIP to work is troublesome. To put chip into boot mode, use this sequence. press reset, PSEN and release reset when PSEN pressed, then turn on USB switch.
rem rem compile doug_at.c and uses dfu-programmer to program the chip. rem https://sourceforge.net/projects/dfu-programmer/ rem
sdcc -mmcs51 --std-c99 doug_at.c pause
use lsusb to see if in bootmode.
You may need to use sudo otherwise you get device not present
sudo dfu-programmer at89c5131 get sudo dfu-programmer at89c5131 erase sudo dfu-programmer at89c5131 flash doug_at.ihx sudo dfu-programmer at89c5131 launch pause
Some Maplin kits used an Atmel Tiny 2313.
It is possible to add it to the Arduino IDE.
http://www.dougrice.plus.com/dev/dhr_avr/ has some pre Arduino tries.
Elector had an Avrdude example using a serial port and resistors.
Once again eBay suggested I buy some DigiSparks. At the price suggested, it was worth a go. They are super for HID keyboard automation. I have needed to reflash the bootloader once or twice.
Adding DigiSparks to Arduino IDE. See:- DigiSparks.
This is very helpful: http://digistump.com/wiki/digispark/tutorials/connecting
Drivers and firmware: https://github.com/micronucleus/micronucleus v2.04
I got this when using the board manager and Win10: "CRC error, file corrupted. Try to repeat later"
This helped. https://github.com/arduino/Arduino/issues/9719
I deleted C:\Users\doug\AppData\Local\Arduino15\library_index.json
When I next opened the IDE it seemed to have installed the new boards.
https://github.com/arduino/Arduino/issues/9719 - Win10 reports CRC error
I have updated my old ADSL2 hub as it was corrupting iPhone updated and the new hub seems to work.
ebay suggested the ESP01 and support to reprogram these has been added to the Arduino.
http://www.dougrice.plus.com/dev/sportstimer.htm - sports timer
http://www.dougrice.plus.com/dev/pulseStretch.htm - measures input pulse and then outputs a pulse 5 times longer
http://www.dougrice.plus.com/dev/pulseStretch2.htm - Using leaky bucket to strech pulse 5 times longer
PIC 10F204 PIC10F204 random number generator.
PIC 16F88 driving IIC display PIC 16F88 driving IIC display
PIC 16F819 IIC/Serial demo with debug of SSPSTAT PIC 16F819 IIC / Serial demo with debug of SSPSTAT
Contact Bounce example Contact Bounce example
pi config - notes on setting up my pi
https://www.sites.google.com/site/unoardusim/services - Prof Simmons has a really good simulator . He recently retired from the Department of Electrical and Computer Engineering at Queen's University, Kingston, Ontario, Canada.
The UseModWiki Actions, presented so that it's easy to copy to your own site. Each of these is implemented using "Local:" InterWiki interwiki links. (InterWiki links that start with "Local:" always point to the current wiki. See InterWikiDocumentation for more information on InterWiki links.