Cromemco dazzler replica project

[Gary C]

Congratulations, this has been a great team effort. I'll update also the Rev D version.

@Gary C: Small correction of your summary/cosmetics in post #859: IC52 was 3408, should be 7408, not a 7403.

Oddly, I had already changed it to 7408 even though I put 7403 in the post.

 

[Hugo Holden]

And here's 4+ minutes of KSCOPE running @ 2MHz:

I think that is the speed K.Scope was supposed to run at, it has that Mesmerizing quality to it, possibly would be good with Pink Floyd's comfortably numb guitar solo track added.

 

[DeltaDon]

I wonder if a Delta Products (later XOR Data Science) 64K DRAM board would function correctly with a Dazzler? It claims to be DMA and Cromemco bank select compatible. There is a note about 14 ᶙs max DMA time limit in the doc's..

Link on S100 Computers website: http://s100computers.com/Hardware M...- XOR/XOR Delta Products 64K-DQ Memory[1].pdf

 

[daver2]

Ok @nullvalue,

Now onto the software...

Are you running CDOS and do you have a copy of the Cromemco assemebler (ASMB.COM) and linker (LINK.COM)?

The editor (EDIT.COM) and debugger (DEBUG.COM) will also be useful too.

What C compiler are you using?

What we should be able to do is to link the C environment to the graphics library (GRAPHZ80.REL) so that you can write your own programs...

Dave

 

[nullvalue]

Ok @nullvalue,

Now onto the software...

Are you running CDOS and do you have a copy of the Cromemco assemebler (ASMB.COM) and linker (LINK.COM)?

The editor (EDIT.COM) and debugger (DEBUG.COM) will also be useful too.

What C compiler are you using?

What we should be able to do is to link the C environment to the graphics library (GRAPHZ80.REL) so that you can write your own programs...

Dave

Yes I am running CDOS and I do have all of those programs. I do not have a specific C compiler in mind, any recommendations?

 

[daver2]

What computer language are you hoping to use to program your Dazzler in?

I suppose I should have asked that question first...

Dave

 

[hmb]

I wonder if a Delta Products (later XOR Data Science) 64K DRAM board would function correctly with a Dazzler? It claims to be DMA and Cromemco bank select compatible. There is a note about 14 ᶙs max DMA time limit in the doc's..

Link on S100 Computers website: http://s100computers.com/Hardware Manuals/Delta Products - XOR/XOR Delta Products 64K-DQ Memory[1].pdf

The only way to find out for sure is to test it so that you can verify this claim by the manufacturer was correct. Your Delta Products DRAM board, and a couple of other DRAM boards also advertised as "Dazzler compatible" were manufactured in the same era as the Dazzler and likely (as a selling point) had design tweaks allowing them to work specifically with with Dazzler's implementation of DMA. Without testing you need to sceptical of manufacturer claims for DMA compatibility of S100 DRAM boards. Unless specifically indicated otherwise (and sometimes, even if the manufacturer claimed it worked) most DRAM boards never worked properly with DMA on the S100 bus.

 

[nullvalue]

What computer language are you hoping to use to program your Dazzler in?

I suppose I should have asked that question first...

Dave

C would be best for me - although honestly I've never developed anything for the Z80 or S100 bus previously so I could go with ASM.. either way I have an uphill battle. I've done a little X86 assembly, but am more comfortable in C.

 

[daver2]

See if you can find a suitable C compiler disk and the associated documentation for running under CDOS and we will take it from there.

Dave

 

[Gary C]

I think that is the speed K.Scope was supposed to run at, it has that Mesmerizing quality to it, possibly would be good with Pink Floyd's comfortably numb guitar solo track added.

and iiiiiiiiii have become

comfortably numb...

epic.

Good choice.

 

[wperko]

Hi,

Check out the DAZZLER files on my website: https://www.brainless.org/Altair/Repository.html There maybe something you don't have.

OTOH, IF you have something I don't have, please send it my way.


.

 

[Hugo Holden]

Actually since we already know that the K.scope runs ok with a 4 or 2MHz clock, and it would probably run ok and slower again on a 1MHz clock, a voltage controlled oscillator could be made that varies its output to between 1 and 4MHz, to control the computer's clock and speed of K.Scope. Then that could be connected to an audio processor output to vary the frequency in proportion to qualities of the music such as overall amplitude envelope and or pitch. So the K.scope then would appear in some ways synchronized with the music.

 

[Eudimorphodon]

It'd probably make a bit more sense to have the Kaleidoscope program sample some D/A converters (wasn't the Dazzler usually paired with a paddle/joystick board?) to manipulate a delay loop (and possibly some other attributes, like colors or some other aspect of the pattern drawing) than fiddle with the CPU speed. I can only imagine all kinds of weird knock-on effects from that.

 

[nullvalue]

See if you can find a suitable C compiler disk and the associated documentation for running under CDOS and we will take it from there.

Well I thought I had found something interesting, Cromemco C, but.. looks like while the resulting program can be executed under CDOS, the compiler itself needs to be run under Cromix which I do not have running. I'll keep looking..



Looks like there's also BDS C but I'll have to test it's CDOS compatibility.

 

[Hugo Holden]

It'd probably make a bit more sense to have the Kaleidoscope program sample some D/A converters (wasn't the Dazzler usually paired with a paddle/joystick board?) to manipulate a delay loop (and possibly some other attributes, like colors or some other aspect of the pattern drawing) than fiddle with the CPU speed. I can only imagine all kinds of weird knock-on effects from that.

I think it would work, that is if the clock speed was not changed too rapidly, only relatively slowly.

 

[nullvalue]

Check out the DAZZLER files on my website: https://www.brainless.org/Altair/Repository.html There maybe something you don't have.

I guess I have to make one of those "Equipped with DAZZLER" labels now!

 

[daver2]

If you fancy learning a bit if Z80 assembler I think you have everything you require already.

In order to use the Dazzler library you have to know what all of the functions do anyhow.

I can walk you through some of the basics (whilst we are looking for a Z80 C compiler that will run under CDOS). I will check the usual Cromemco repository later.

Dave

 

[daver2]

I have found three (3) potential C compilers on disks 279, 603 and 966.

279 is version 5.00 of Cromemco's compiler. It looks to have a version that compiles under CDOS.

966 is a really old (version 02.00) of this compiler.

603 is a BDS compiler.

There is also a 16K extended BASIC containing Dazzler functions somewhere.

I would suggest trying disk 279 myself.

Dave

 

[nullvalue]

If you fancy learning a bit if Z80 assembler I think you have everything you require already.

Yeah I think I'm leaning towards just using assembler now. Thinking about it and looking at some code examples, I don't think using C for this kind of development would really make things any easier. Especially looking at how inefficient the compilers sometimes are, I'd be trying to optimize the C code to produce better asm, so I may as well just start in asm..

 

[daver2]

Perhaps you could create a CDOS disk with ASMB.COM, EDIT.COM and LINK.COM on it.

Copy the Dazzler files gdemo.z80 and graphz80.rel onto it also.

Then, try and assemble gdemo.z80 to make gdemo.com as follows:

ASMB gdemo
LINK gdemo,graphz80/E

The linker should respond with:

[xxxx yyyy zz]

Then immediately type:

SAVE gdemo.com zz

Where zz is the value that LINK gave us.

Then try and run gdemo and see if it works.

When we have shaken the bugs out of the build process we can modify gdemo.z80 and see if the changes are reflected in the executable.

This should provide us with a framework for creating our own programs.

Dave