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Subject: Building a new computer
Replies: 26 Views: 1886
plzgvhug 19.01.10 - 02:35am
Im going to build a spectacular new Z80 based computer. Features of this machine will include most of the same operating system as my previous mpf1d but with some additional features. I will be running the z80 cpu as fast as i reliably can so maybe 12 to 16 mhz which will be upto 4 or 5 times faster. Im going to add in a voltage controled filter (VCF) and a wave shaper, A low freq oscillator (LFO) and an envelope generator to the design so i can develop and run sound synthersizer applications. *
plzgvhug 19.01.10 - 02:49am
As in the previous design an an*louge to digital converter (ADC) and a digital to an*louge converter (DAC) will be added to allow sampling, processing and playback of audio signals but with much higher sampling rates than i could before. *
plzgvhug 19.01.10 - 03:02am
At the moment i am currently in the process of sourcing and buying parts for the project which is going to take some time. *
plzgvhug 25.02.10 - 01:13am
I now have about 99 percent of all the parts needed to build my new computer. *
plzgvhug 6.04.10 - 08:14am
yes ay i got a few hours of free time to start the build. Im working on the keyboard and LED display board that will be the user interface. It wont be long before its built and then i shall post a photo. *
plzgvhug 16.04.10 - 07:42pm
I have finally finished the new keyboard and have uplo
aded two photos in the files section. *
plzgvhug 25.04.10 - 11:32pm
i have started work on the mainboard and taken a photo
in its early phase of construction. I will add more photos as the build progresses. *
plzgvhug 2.05.10 - 11:57pm
i have added another 2 photos of the build in progr
ess - mainboard build progress 2, and mainboard underside build 2. *
plzgvhug 4.05.10 - 01:43pm
heres another 2 photos of the build added to the files se
ction. Mainboard progress 3, and mainboard underside 3. Hopefully the next time i take photos the board will be connected to its keyboard display and powered up. *
plzgvhug 5.05.10 - 02:45pm
HURRAY! First time power up and everything works! I uploaded a new photo to the files section - z80 board power up! The system is just a minimal computer at the moment just for now but the extra hardware will get added soon. *
cs.punk 6.05.10 - 09:25am
lol thats allota newspaper you know ;) you should open a FB page or something =D *
cs.punk 6.05.10 - 09:26am
so uhm basically you have full knowledge of each uhm chip? what pins does what etc etc? What sorta thing can you do with it if i may ask lol? *
plzgvhug 6.05.10 - 12:05pm
i download all the manufactures data sheets for all t
he chips and various other parts so i know if a part is suitable and how it functions. Some of them are huge! Some have specs and wiring diagrams and some like the cpu have alot of info you gotta read just to know how to operate the thing. *
plzgvhug 6.05.10 - 12:18pm
A co
mputer of this type can be used for a variety of things where a huge pc is not needed. For example it could be used to develop a small robotic vehical, or it could be used to develop a security system for your house, or it could be used to play old 8bit games on when an lcd display is added to it. You could design a washing machine controller that plays a tune when the washing is done... *
plzgvhug 6.05.10 - 12:27pm
... It could be used to make a midi sound synthersizer, or how about a telescope position control system... or you could run CPM operating system on it and use it like a mini desktop computer with a wordprocessor/spreadsheet software or program in BASIC, C, or FORTH, or how about a weather station, endless possibities. *
plzgvhug 13.05.10 - 10:10pm
ive added another pic in the files section, build progress 5.. you can see a midi interface taking shape to
the top right. Im using a 6850 serial port chip here. The Z80 CTC (counter time chip) to the left of that and further to the left is the ram bank switch. *
plzgvhug 30.05.10 - 10:00pm
ive started the build of the powersupply as you can see in build progress 6 and powered up photos in the files section of this group. This powersupply has two regulated outputs for 5 volts at upto 1.5 amps and 12 volts at 1 amp. I have a special overvoltage circuit to protect my precious computers from damage in the the event of a regulator failure. *
plzgvhug 30.05.10 - 10:14pm
if the 5 volt outputs should go above 5.17 volts then a special circuit shorts out the supply and blows a fuse so protecting my computers from damage from exceding maximum voltage. The 12 volts is to power the fan that will blow air down onto the heatsinks. The box is having the holes drilled in it for the fan and connectors so will post another pic when thats complete. *
plzgvhug 3.06.10 - 07:57pm
i have posted another photo in the files section called mainboard complete. On the board i
s 256kb of battery backed ram, two 8 bit parralel ports, 4 counter/timer channels, and 8 bit an*logue to digital converter and an 8 bit digital to an*logue converter. A serial port with a midi interface. Finally a 24 in/out parralel port for the keyboard and display. *
plzgvhug 5.06.10 - 09:36pm
The Z80 and some of its peripharal chips on the mainboard are using a clock signal which is switchable between two clock speeds by the switch on the lower left of the mainboard. These being 4mhz for compatability reasons and 8mhz so the board can be run faster. But now the board will run even faster ... *
plzgvhug 5.06.10 - 09:45pm
... Because i have overclocked the Z80! Its now running at 10Mhz! Ive been running it for hours and i
ve had no errors or problems or anything even getting warm on the board . Im so confident that next ive decided to increase the overclock to 12 Mhz! *
plzgvhug 22.07.10 - 09:37am
its been a little while since updating this topic but ive been running my system now at 12Mhz for many weeks without problems. Ive also been working on the anti aliasing filter for the an*louge to Digital Converter and the Filter on the output of the Digital to an*louge Converter. These are on a breadboard for testing right now. *
plzgvhug 22.07.10 - 09:45am
i have also been working on parts of the synthersizer circuitry and have a working VCF (Voltage Controlled Filter) and a VCA (Voltage Controlled Amplifier). I am very happy with the VCA but not so with the VCF yet since it sounds abit shrieky and harsh it needs some work yet. *
plzgvhug 22.07.10 - 09:52am
and im going to build a ADSR (Attack Decay Sustain Release) envelope generator based on a 7555 timer today *
plzgvhug 1.08.10 - 02:38pm
Heres a new photo of some of the synth circuits that i have recently built. They look abit messy because they are only temporarily being tested on this breadboard to make sure everything works perfectly then later will be built into the new Z80 computer. *
plzgvhug 3.10.10 - 04:31pm
its been a while but ive done a bit of work and i have now completed the power supply for the system. The LCD display is working and just needs a box to finish it. Theres 3 new photos in the files section. *
plzgvhug 14.11.10 - 11:58pm
I now have put up a link to my videos on youtube under my username spacehopper03. *
