Raven. A homemade Atari-like computer

[agranlund]

And the DSP sprung to life and said hello world
Just a simple program that sets the HF2 bit then toggles HF3 in an infinite loop, but proves I can upload and run code through the HI08 interface.

I'm very happy this worked!

Code: Select all

	org p:$0
start:	bset	#3,x:$ffffc2
loop:	bchg	#4,x:$ffffc2
	rep	#$fff
	nop
	jmp	loop

Screenshot 2026-06-29 at 22.59.01.png (260.51 KiB) Viewed 717 times

Apart from this, I am booting to my usual desktop ok.
Not everything has been tested in detail but it's looking good so far.
Next interesting test would be the DAC and ADC sound paths to the DSP.

One minor mishap is I made the internal speaker on/off control reverse compared to Falcon.
It's the same register and bit as Falcon but ON for Falcon means OFF for Raven when using the control panel accessory.
This is easily fixable by a workaround in Ravens xbios so I'm not really too bothered other than being annoyed by myself for not double checking this beforehand.

[exxos]

[dml]

That's amazing progress. You built that thing so fast! I wanted to reply sooner but being a dolt, forgot my login password

A bit jealous you have that fancy new DSP to play with but if I can find the bits I might try to build an A2 at some point. (I did run out of 68060s with the first build though)

[redpixel]

You are the GOAT @agranlund Really amazing that you've managed to pull this off repeatedly, getting to a working board with basically no re-work needed. Both design and soldering!

A bit jealous you have that fancy new DSP to play with but if I can find the bits I might try to build an A2 at some point. (I did run out of 68060s with the first build though)

There is a guy (screemo) on Amibay selling 68060's for 279€ a pop. I think it's a really fair price. I bought the one for my Raven from him and it's worked perfectly. I really have no idea where he got all of them from as it seems he's sold probably 100+ by now and still has more to spare

[agranlund]

Thanks @redpixel !
I don't know intricate details and best practices of EE so to be fair I'm constantly surprised by things actually working

[agranlund]

Internal speaker works and can be controlled the same way as on Falcon.

IMG_6083.jpg (84.55 KiB) Viewed 1630 times

IMG_6082.jpg (111.37 KiB) Viewed 1630 times

Digital pot for adjusting the volume coming out of the YM also works.
Practically, this volume control will be exposed through rvsnd.

I recon next up might be writing a DSP program to verify that the DAC and ADC connected to it are working as expected.
And at some point start implement the Falcon dsp xbios.

Some other stuff still waiting to be tested:
fan PWM
fan RGB
dsp: external sram
dsp: essi0 (DAC and ADC)
dsp: essi1 (general purpose header)
i2c: eprom with mac address

[Oldskool]

Very cool!!!! Always nice to read your updates....

[agranlund]

DSP -> DAC -> Line and Speaker output verified ok.
Gave me quite the jumpscare when the sawtooth buzzer test code started working

[ctirad]

Hi, I don't know if this has already been said here, but what about adding a CT60 compatible expansion header to some further revision?

[Mikerochip]

DSP -> DAC -> Line and Speaker output verified ok.
Gave me quite the jumpscare when the sawtooth buzzer test code started working

Unrelated, but, since I haven't looked at my BGA ram, and routing it in a bit, I decided I'd just buy the SRAM.
I have a case! The nifty Fractal Design Pop Silent Mini (I wanted one with a window, but, I can't find it for sale anywhere), with it's two hidden 5.25" bays, and hopefully, a 68LC060 on the way.

...

6x of those SRAM ICs are now €400 :O (inc. vat) HOLY PRICE INCREASE BATMAN.

Tomorrow, I'll take (another) serious look at routing that bga PSRAM. I mean. It'd be madness not to.