H4G - Mongrel SMT Edition

[Icky]

:logo: - H4G Mongrel SMT Edition

Starting a thread where @exxos and I will update on all the fixes and changes as we work on the next board H4G.

We will start with all the fixes from the patch info https://www.exxosforum.co.uk/forum/viewt ... =78&t=2335. Below is the list of all the patches and the fixes for them to start this thread off.

Holes - a few tweaks where required to holes on the board. The following pictures show the improvements and fixes.

Screenshot 2020-05-20 at 13.37.23.png

Screenshot 2020-05-20 at 13.48.08.png

Screenshot 2020-05-20 at 13.36.58.png

Battery - a route close to the pad was exposed with the potential to short. The route has been moved out of the way.

Before:

IMG_4715.JPG

Fixed:

Screenshot 2020-05-20 at 14.42.56.png

MFP OSC - The MFP OSC was orientated vertically which obstructs mounting a floppy drive. The OSC has been laid flat.

Before:

IMG_4545.jpeg

Fixed:

Screenshot 2020-05-20 at 16.25.15.png

Missing DTACK Route - There was a missing DTACK route between the CPU and Blitter.This has been added.

Before:

Capture.PNG

Fixed:

Screenshot 2020-05-20 at 16.31.46.png

DMA Resistor - One of the DMA resistors was underneath the DIL socket location. This has been moved out side of the socket area.

Before:

dmares.jpeg

Fixed:

Screenshot 2020-05-20 at 16.41.12.png

BGACK Pull Up - BGACK was missing a pull up. There is a spare pin on RP8 we can use.

Before:

oopsies.JPG

Fixed:

Screenshot 2020-05-20 at 16.56.45.png

4MB RAM SIMM - Route was to the wrong pin so needed moving to enable the 4MB to be seen.

Before:

1.JPG

Fixed:

Screenshot 2020-05-20 at 18.21.45.png

RS232 Fix - Route to Pin 20 needed to go to Pin 7 instead.

Before:

px.JPG

Fixed:

Screenshot 2020-05-20 at 17.24.29.png

DAC Fix - ADC0 lines were tied to GND they need to be balanced between 5v and GND.


Before:

dacf1.JPG

Fixed:

Screenshot 2020-05-20 at 17.34.36.png

DMA Issue - To get the DMA to work required a patch board. This board circuit has been included in to the H4G schematic.


Before (patch board):

IMG_5281.jpeg

Fixed:

Screenshot 2020-05-20 at 17.51.22.png

[PaulJ]

Sign me up for 2 or 3.. like the SMT construction much better, looks great. :excited: :excited: :excited:

[derkom]

I'd build another one. :D

[DoG]

Not SMT on the 74LS245? Or is this a WIP? All 74LSxxx chips will be SMT I hope.

[exxos]

Not SMT on the 74LS245? Or is this a WIP?

Icky hasn't posted everything yet :)

[Icky]

Not SMT on the 74LS245? Or is this a WIP?

WIP @DoG. You dont want to see the spaghetti its in at the moment. Will be updating pics of all the sections as they turn to SMT.

[DoG]

I thought so. DoG is happy :D

[Tomswork]

Sign me up for 2 boards as well.

Tom

[exxos]

I will start a new thread soon for interested parties in the new board..

[PhilC]

I will start a new thread soon for interested parties in the new board..

Sign me up cos its gonna need breaking