WANTED DSTB1

[LarryL]

Hi,

Has anybody a DSTB1 for sale?
Was thinking about building them, but seems hard to get hold of some of the used chips (CPLD) these days…

I am located in Germany, but importing from UK usually works fine

Regards
Michael

[coonsgm]

I'll jump on the bandwagon as well here!

[Badwolf]

I'm still not 100% convinced DSTB1 works on all machines as well as it ought (it's the SDRAM -- the CPU acceleration's fine).

I've been working on it a bit recently and I'm still seeing things I don't understand.

Just a caveat if anyone's looking to make them -- I'm not proposing a new board spin yet, but there may be some new firmware to come soon.

BW

[DoG]

I might be able to built some.

But I don't really have any ready for sale. But when I check what I ordered, when I built mine, I seem to have order some multiple parts of each to make a few more units. But it was a while ago I built mine, so I don't know where I have all the parts at the moment. I also have some personal project I want to start on/finish. So what I'm saying is, it's gonna take a while to make them. Soon summer vacation and all as well. Enough excuses I suppose.

So... if you can wait a while I'm up to build and sell a unit.

[LarryL]

I might be able to built some.

But I don't really have any ready for sale. But when I check what I ordered, when I built mine, I seem to have order some multiple parts of each to make a few more units. But it was a while ago I built mine, so I don't know where I have all the parts at the moment. I also have some personal project I want to start on/finish. So what I'm saying is, it's gonna take a while to make them. Soon summer vacation and all as well. Enough excuses I suppose.

So... if you can wait a while I'm up to build and sell a unit.

well, I have time
I am also thinking about building it (or letting it partly build by JLCPCB)

[LarryL]

I'm still not 100% convinced DSTB1 works on all machines as well as it ought (it's the SDRAM -- the CPU acceleration's fine).

I've been working on it a bit recently and I'm still seeing things I don't understand.

Just a caveat if anyone's looking to make them -- I'm not proposing a new board spin yet, but there may be some new firmware to come soon.

BW

cool!

I have downloaded the files from the Github and loaded them into KiCAD
Still struggeling a bit because of a missing symbol (the SDRAM) - but I think I figured out the right connections by looking at the PCB

I checked with JLCPCB about the components - seems they have most of the items on stock, even the Xilinx seems to be available
unfortunately they only populate one side of the PCB, not both

Not sure, if I dare to make a production run - lets see...

[phjanderson]

I'm also interested. In case someone decides to make a batch

[Wolfgang]

I was able to get a DSTB1 for my MegaST. I flashed the 20231016 firmware but have so far not been able to get a stable system.
As soon as the Blitter is active, it doesn't take much to get all kinds of crashes. UltraSatan seems not to work at all. LightningST's IDE interface seems to work a little better, but when the Blitter was used, the file system got corrupted.
Interestingly my system seems to be more stable with the MC68000P12 CPU than with the MC68HC000P16 CPU. It even found the UltraSatan partitions.
I hope to get a MC68000P12F (16MHz) soon and will retest again.

[Badwolf]

I think I ought to warn people off building these for now.

I've spent a fair amount of time chasing my tail on the firmware for these and have reluctantly come to the conclusion the design's not reliable.

I think the first problem is trying to service DMA -- blitter, hard discs, floppies, etc. I should never have tried to do that as the firmware as originally written relied on the CPU and RAM clocks being related and they aren't when doing DMA.

So if you do use DSTB1, don't enable blitter is advice number one.

Also I don't think DSTB1 plays nicely with some hard disc emulators. My ACSI2STM seems to work OK, but my PicoHD is a non-starter. Be careful here.

However even taking those things into account there are some crashes I can't explain yet. I can pass memory tests all day, but then programs executing from AltRAM will randomly fail.

I have to reluctantly assume for now it's a design problem.



In short, if you have built one and it works for you, fantastic. But please don't use the blitter with it.

If you've not yet built one -- perhaps consider an alternative design or hold off for a rev 2*


Cheers,

BW


[*] That may be a fair hold, FWIW.

[LarryL]

Thanks for the warning - much appreciated

Will wait for Rev 2

I‘ll keep my fingers crossed