will it compute? btl's attempt to build the H4

[btl]

This is how my SMD stuff looks like. Not perfect but clean enough.

20191207_140918.jpg (117.23 KiB) Viewed 4203 times

[PaulJ]

Looks good.

[btl]

Thank you Paul, in the meantime, last resistors are in. R3 and R4 were tricky,
they go through the plastic frame of the MIDI ports...

Lets do the capacitors now and then finish off with the 68k sockets

Edit 17:00: Capacitors and Sockets are done. Lets go through the hotfixes.

Edit 17:40: getting close, setting jumpers!

[btl]

OK, i connected my trusty C=1084s, connected my Lab PSU (current limiting to 1.5A) and fired it up:

- no magic smoke
- solid white screen output
- no little green desktop
- no reaction to reset button

ah! forgot the Falcon RAM board ...

but the same solid white screen. My TOS ROM is the one from the Exxos STE ROM switcher,
with 2.06 and EmuTOS in it.

Will start troubleshoot tomorrow, or monday.

[exxos]

STE ROM may not work anyway.. TOS206 wont, I assume EMUTOS is larger than the ROM space so probably wont boot unless its a STF version.

[btl]

Ah, i see.

I got an 27c4096 OTP prom, is there a file i can can program directly? I only have one try...

[exxos]

All tos versions are online anyway, though as to if you need to byte swap it with your programmer or not is another matter..

https://www.exxosforum.co.uk/forum/viewt ... f=25&t=116

[btl]

Thanks! I got me TOS1.04 and EmuTOS 192k. I better erase my STE Eprom and try
if byteswap is needed or not before putting into an OTP PROM.

[btl]

Oh my!

i just programmed my EPROM, non-byteswapped TOS1.04 and byteswapped EmuTOS.

It didn't change anything, so i started the Troubleshoot according to the H4 Troubleshoot thread.
When i pressed and held reset in order to check the Reset Line, the little green EmuTOS desktop
came on the screen!

20191208_174142.jpg (178.86 KiB) Viewed 4153 times

So my reset switch is other than expected or my reset IC is doing the opposite as requested.
After switch on, i need to release the reset switch for a second, then hold it for the System to boot.

Therefore, besides my reset curcuit issue, and me using the wrong TOS Chip due to reading too
little of existing info, this was a no troubleshoot, instant booting H4 board.

And yes, i run it with a 64-legged horse in the expansion slot!
Lets connect some keyboard...


greets,
btl

[derkom]

Are you missing the jumper in the Flashy Clock socket area? That may be affecting your reset behaviour.