New hardware revision?

Talk about everything hardware related
jonwil
Posts: 3
Joined: Sun Sep 16, 2012 1:55 pm

Re: New hardware revision?

Postby jonwil » Mon Sep 17, 2012 11:44 am

I would imagine the 68000 would be a LOT easier to get than a 68030. Also, once you start getting into the realm of fancy 32 bit parts like the 020/030/040/060, it starts getting a bit more complex in terms of the stuff you need to make it work (heck, most of the 32-bit parts have an MMU and can run a full-on Linux Kernel)

And I wasn't thinking OPL for the sound, I was thinking of a sound system more like that used in many arcade games that used a YM2151 FM synthesis chip and another chip to handle raw sound samples (used in the arcade games for sound effects and percussive samples that the 2151 couldn't do)

Since storage space isn't an issue (due to the inclusion of a hard disk and floppy disk) there is no need for the sort of sound chip these arcade boards used (usually something like an OKIM6295 ADPCM chip) and a cheaper simple DAC could be used I guess.
And assuming the rest of the system is built properly (and the 68k is fast enough) the tight timing many of these arcade boards had that meant the sound hardware had to be controlled via a separate CPU such as a Z80 isn't an issue.

Biggest downside would be the lack of music written for the 2151. (what music exists for it most likely exists in the form of the ROM files for the arcade games that used the 2151) That and the fact that you would probably need a YM3012 Stereo DAC chip or similar to do anything useful with the output of the 2151.

EDIT:
I should add that you probably want the 68HC000 CMOS version rather than the 68000 HMOS version as the HMOS version was discontinued in 1996 or so but the CMOS version may still be in production (or if not, certainly easier to track down)

simon
Site Admin
Posts: 744
Joined: Thu Sep 13, 2012 9:35 am
Location: Luedenscheid, Germany
Contact:

Re: New hardware revision?

Postby simon » Mon Sep 17, 2012 5:58 pm

I would prefer the MC68000 as well. This way the design changes will be minimalistic.

For the audio I am really not sure. I really like the SID sound. Maybe we could do another audio source as option. Route these signal to the input of the SID? But if we need DMA for audio, the DMA needs a good timing and the bus situation could become more complicated. Think of the clever interleaved timing of the Amiga for example.

What about the lack of music? Do we have music artists with us? :)

Simon

jonwil
Posts: 3
Joined: Sun Sep 16, 2012 1:55 pm

Re: New hardware revision?

Postby jonwil » Tue Sep 18, 2012 3:17 am

Doing stuff with a SID (or any of the other programmable sound generator type chips of that era like the Atari POKEY or the General Instrument AY-3-8910) requires writing raw code whereas using an FM synthesis chip like the YM2151 or the OPL means you can probably just write something to play music from a file (e.g. a MIDI player)

That would mean that anyone who can make MIDI files can make music for this machine. (and you could use the 1000s of existing MIDI files that are out there)

But if you think the SID produces better sound, feel free to use it :)

paulinho.cabral
Posts: 1
Joined: Sun Sep 16, 2012 3:11 am
Location: Brazil
Contact:

Re: New hardware revision?

Postby paulinho.cabral » Tue Sep 18, 2012 3:37 am

Hey man, sorry that I’m a little bit late in the thread to say fantastic work. And “if you build it they will buy” (at least one Brazilian will :) )!

netwar
Posts: 40
Joined: Mon Sep 17, 2012 5:31 am
Location: North Carolina,United States of America

Re: New hardware revision?

Postby netwar » Tue Sep 18, 2012 5:54 am

Sure (im typing this at 1am before i goto sleep) I'll get some pictures taken after work tomorrow should have them posted before 5pm I need to quickly work out a kink in the furance (fuel is not lighting correctly) but yep i can also send some pics of a heat sink i already had made and some ingots I have.
-Netwar

simon
Site Admin
Posts: 744
Joined: Thu Sep 13, 2012 9:35 am
Location: Luedenscheid, Germany
Contact:

Re: New hardware revision?

Postby simon » Tue Sep 18, 2012 7:21 am

jonwil wrote:Doing stuff with a SID (or any of the other programmable sound generator type chips of that era like the Atari POKEY or the General Instrument AY-3-8910) requires writing raw code whereas using an FM synthesis chip like the YM2151 or the OPL means you can probably just write something to play music from a file (e.g. a MIDI player)

That would mean that anyone who can make MIDI files can make music for this machine. (and you could use the 1000s of existing MIDI files that are out there)

But if you think the SID produces better sound, feel free to use it :)


Aren't there midi players for the C64? At least I am aware of the Midibox which uses a SID as option if I recall this correct.
Writing raw SID code sounds more difficult as it is. All audio is played from a register dump which is prduced with a PC. But I agree, for SID music files coming from C64 software, one would have to port the native player.

What do others think about SID or FM synthesis chips?

netwar wrote:Sure (im typing this at 1am before i goto sleep) I'll get some pictures taken after work tomorrow should have them posted before 5pm I need to quickly work out a kink in the furance (fuel is not lighting correctly) but yep i can also send some pics of a heat sink i already had made and some ingots I have.


I am curious how it looks like. :)

Simon

netwar
Posts: 40
Joined: Mon Sep 17, 2012 5:31 am
Location: North Carolina,United States of America

Re: New hardware revision?

Postby netwar » Tue Sep 18, 2012 9:40 pm

Here are the pictures (unfortunatly we are having servre thnderstorms and torando warnings right now in my area so i can't go out back to the foundry (it is open air away from the house for a reason :lol: )
The pictures are attached and i'll describe the setup here (ps those aren't all my ingots I have more in the shed)
I have a three foot tall one foot wide steel and firebrick furnace.
It is homemade, originally using coal and wood for fuel then converted it after learning the ropes of basic metallurgy to a vegatable oil burner.
Its highest operating tempature I have recorded is 2385 degrees farenheight (1538 celcius) which is barely enough to melt iron if i leave it in for about an hour.
The most aluminum i can process in one run (about two hours) is 20-30 pounds of aluminum
I usually can produce this 30 pounds of aluminum by melting 40 pounds (I have a high purity but the ingots in the pictures are not polish nor finished the purification melt)
I use welders goggles,gloves,apron,boots(saftey first)
The tools i use are two channel locks for moving the crucible, a firepoker to repostion the crucible once inside the furnace, a cupcake tray(OF DOOM! :twisted: ) to form basic ingots,Hammer and anvil for misc uses (removing slag off the tools etc)
The air injection system for the furnace is a three foot long one inch diameter pipe with a hairdryer to push the air through
the pictures will be hosted here http://s1154.photobucket.com/albums/p523/warmowed/

simon
Site Admin
Posts: 744
Joined: Thu Sep 13, 2012 9:35 am
Location: Luedenscheid, Germany
Contact:

Re: New hardware revision?

Postby simon » Wed Sep 19, 2012 9:35 am

Sounds and looks interesting. I imagine how a aluminum case would look like. :)

For the hardware... I added some design files to the internal member area. So if you want a Kiwi let us get on the work. 8-)

Simon

benchoff
Posts: 6
Joined: Wed Sep 19, 2012 4:54 pm

Re: New hardware revision?

Postby benchoff » Wed Sep 19, 2012 5:05 pm

As for the power supply, have you looked at just using a regular old ATX supply?

Rather, would an ATX supply be clean enough?

simon
Site Admin
Posts: 744
Joined: Thu Sep 13, 2012 9:35 am
Location: Luedenscheid, Germany
Contact:

Re: New hardware revision?

Postby simon » Wed Sep 19, 2012 9:28 pm

As for the ATX power-supply, I replyed in its own thread.

As for the case, what about changing the PCB form-factor to re-use an available case which is easy to get? For example fitting it into an Amiga 500 case. I assume, even the A500 keyboard could be used, as this should be a matter of programming the Atmega8.

Simon


cron