H4G - Mongrel SMT Edition
Posted: 20 May 2020 18:31
: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.
Battery - a route close to the pad was exposed with the potential to short. The route has been moved out of the way.
Before: Fixed:
MFP OSC - The MFP OSC was orientated vertically which obstructs mounting a floppy drive. The OSC has been laid flat.
Before: Fixed:
Missing DTACK Route - There was a missing DTACK route between the CPU and Blitter.This has been added.
Before: Fixed:
DMA Resistor - One of the DMA resistors was underneath the DIL socket location. This has been moved out side of the socket area.
Before: Fixed:
BGACK Pull Up - BGACK was missing a pull up. There is a spare pin on RP8 we can use.
Before: Fixed:
4MB RAM SIMM - Route was to the wrong pin so needed moving to enable the 4MB to be seen.
Before: Fixed:
RS232 Fix - Route to Pin 20 needed to go to Pin 7 instead.
Before: Fixed:
DAC Fix - ADC0 lines were tied to GND they need to be balanced between 5v and GND.
Before: Fixed:
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): Fixed:
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.
Battery - a route close to the pad was exposed with the potential to short. The route has been moved out of the way.
Before: Fixed:
MFP OSC - The MFP OSC was orientated vertically which obstructs mounting a floppy drive. The OSC has been laid flat.
Before: Fixed:
Missing DTACK Route - There was a missing DTACK route between the CPU and Blitter.This has been added.
Before: Fixed:
DMA Resistor - One of the DMA resistors was underneath the DIL socket location. This has been moved out side of the socket area.
Before: Fixed:
BGACK Pull Up - BGACK was missing a pull up. There is a spare pin on RP8 we can use.
Before: Fixed:
4MB RAM SIMM - Route was to the wrong pin so needed moving to enable the 4MB to be seen.
Before: Fixed:
RS232 Fix - Route to Pin 20 needed to go to Pin 7 instead.
Before: Fixed:
DAC Fix - ADC0 lines were tied to GND they need to be balanced between 5v and GND.
Before: Fixed:
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): Fixed: