Phil C's Raven build

[PhilC]

Quite a delay whilst I'd been unwell etc but been having a look at getting the Raven finished over the last week.

And it's all finished bar the Simms. Stupid me went and ordered some 1mb x16 Simms instead of the 64x16 ones, thanks dyslexia. I didn't notice until I'd done a nice job of soldering them on.

So now have to wait for a month until I can afford £150 worth of ram chips. I did read somewhere that other 72 in Simms will work. Do you guys have any suggestions as to which ones? You can get 16mb edo Simms at a reasonable price and might be able to get them before next month.

[kodak80]

The Raven SIMM sockets are custom and cannot use standard 72 pin RAM SIMMs.

[PhilC]

The Raven SIMM sockets are custom and cannot use standard 72 pin RAM SIMMs.

Thanks, I thought that might be the case. Next month it is then.

[PhilC]

Okay so I put the ram on the credit card and it's now installed and the Raven powered up.

I had fun trying to get the rims programmed at first due to a power issue. Plugged into a different USB socket and off it went.

So with the monitor rom programmed I tried to power it up but all I get on the serial is a singular dot with each power up.

I had installed the LS148 the wrong way round which has popped it unfortunately and found that one of my GALs died as well. I've swapped the GAL but no spare LS148 just yet. I'll have to get the scope out tomorrow but think it's likely just a bad soldered joint or something similar.

[PhilC]

Turns out I have a duff XR68, so I've ordered that as well and am hoping that's the last part I need.

[PhilC]

Fitted the new chips and found a reset issue, as in it wasn't resetting. Fixed that and now I suspect I've not programmed the 1508 properly. It's getting the clock signals etc but not doing much with them. Oh well, kicad downloaded and the scope out again tomorrow when I get a chance, to try and work it all out.

I don't think I'm far away from having a running Raven.

[PhilC]

Had a bit of luck today, changed the CPU oscillator for a 33mhz one that I had in the drawer and still nothing from serial.

I was probing around on the 68150 and suddenly got a whole screen full of text on the serial, reboot, it worked again and then it didn't

It turns out I had a dodgy 68150 socket. Changed the socket and away we went.

Reflash the rom with the tos firmware and we even have a tos desktop........ Sort of.....

The Mach 32 is recognised but has no VGA output at all. Plugged in my ET4000 and we get this:

PXL_20250508_181627980.jpg (360.6 KiB) Viewed 88 times

The serialpnitor only seems to show 256k of video ram.

I'm sure I have another et4000 somewhere, I'll have to go find it.

[exxos]

Reflash the rom with the tos firmware and we even have a tos desktop........ Sort of.....

Ya'broke it!

[PhilC]

Reflash the rom with the tos firmware and we even have a tos desktop........ Sort of.....

Ya'broke it!

But I always manage to fix it

[JezC]

Ya'broke it!

But I always manage to fix it

Careful you don't jinx yourself here @PhilC!