H4G - Mongrel SMT Edition

[Icky]

Great. Will the X2 also work/fit? Maybe move down the MFP a bit and xtal might need moving?

Did some measuring and the X2 will fit over the top of the XTAL and SMT MFP68901. Clearance is good. However have not tested an X2 and need to check the pinouts.

EDIT: checked X2 card and has same pinouts so should work.

Idea = brilliant , choice of music = not so good.

Where can one aquire one of these S2 boards?

Can never please everyone, especially @PhilC - https://www.serdashop.com/waveblaster also available on evilBay etc.

I requested Bomb Jack and Frankie goes to Hollywood

I did play Bomb Jack @exxos but the music was a little annoying

[PhilC]

Thanks @Icky ill get one. Any chance of sharing the schematic? I can probably do a how to guide at some point for the existing H4s

[Icky]

- Extra PSU Connector Near Floppy

We have also placed a PSU connector right by the floppy drive area to make it easer to connect and not have wires trailing over the board. The connector does not have a 12V line.

Screenshot 2020-06-02 at 23.42.43.png (542 KiB) Viewed 8487 times

[PhilC]

@Icky well done, very good idea

[Icky]

- MAX238 to SMT

@exxos and I have found that the pcb fab also stocks an SMT version of the MAX238 so we have also moved that chip to SMT too.


Before:

Screenshot 2020-06-04 at 08.37.10.png (410.16 KiB) Viewed 8444 times

After:

Screenshot 2020-06-04 at 08.36.25.png (347.96 KiB) Viewed 8444 times

[Icky]

- Gotek HD Floppy Jumper to Remove HD Select Wire

@Icky to have the floppy HD selection work with a gotek it needs a jumper from floppy pin 32 to the drive 0 main board jumper. Is there any chance to get this put in as a lan since this floppy connector pin has no existing connection?

@PaulJ suggested we had a jumper to help send the HD select line on Pin 2 of the Floppy connector if using a Gotek. @kodak80 did a good guide on using a separate cable but by having a jumper on the board you can just use the Floppy cable.
HD guide - https://www.exxosforum.co.uk/forum/viewt ... 551#p33807

To achieve this feature we have extended JP18 to have three pins. If you have the HD mod fitted and are using a Gotek with its config changed by placing the jumper on pins 2 and 3 you don't need an extra cable to the Gotek.


EDIT: After a bit of research by @exxos we have established Pin 2 on floppy drives are not connected so we have gone back to a two pin jumper and directly connected the HD Select line to Pin 2 on the floppy header.

Screenshot 2020-06-04 at 17.10.36.png (207.37 KiB) Viewed 8423 times

[Icky]

- Jumpers Removal and Component Naming Clean-up

We have also removed all the jumpers around the MMU, GLUE etc as they are really for development purposes. To make sure that if anyone still wants to develop around the clocks all the clocks to each chip have a 0805R which can be tapped into (example of the GLUE 8MHz in the pic). In addition we have made sure the DE line between the GLUE and MMU is by default wired but if required a simple track break will allow pads to be used to tap into the DE line.

Screenshot 2020-06-06 at 11.54.22.png (101.92 KiB) Viewed 8375 times

[Icky]

Now we have completed all the fixes found on the H4F on the H4G and added a few more suggestions we are going to start on the larger areas namely the 3.3V BUS.

In light of this we are now closing the H4 platform and will be taking the H4G on to the H5 platform where the 3.3V BUS will be one of the major features.

We will be posting shortly about the H5A with its 3.3V bus in a new thread under the H5 Info area - https://www.exxosforum.co.uk/forum/viewforum.php?f=89