ALPHA MODIFICATIONS

[exxos]

Is the description for RESET FIX complete? Icky has moved the leg of the resistor which is not in the description, but without it the cut tracks don't really make sense.

edit: Ah, read further down. Also the resistor connects to internal plane I guess. I'm not used to 4 layer boards

The original fix I did move the resistor to connect to vcc.. But it wasn't actually needed because the resistor was actually already connected to vcc on one of the internal planes.. I did edit the post.. So should be correct..

[exxos]

1772 / RS232 RD FIX

Thanks to PaulJ for finding this one!

Fixes a common name "RD" between the 1772 & RS232 RD lines.

Cut track on the bottom of the PCB as shown below.

rdfix.JPG (199.89 KiB) Viewed 9582 times

[exxos]

EXTERNAL FLOPPY PORT FIX

DO NOT SOLDER THE EXTERNAL FLOPPY CONNECTOR

Topic below shows new fixed pinout for the floppy connector..

https://www.exxosforum.co.uk/forum/viewt ... =19&t=1248

[exxos]

1772 DMA BUS SHORT FIX

This fix is partly classed as optional.. There will be no issue if just using floppy drive (That we currently know about). When the hard drive is attached, it could potentially damage the DMA & 1772 chips. It is also possible the hard drive or floppy drive could malfunction when the hard drive is attached.

This isn't a bug as such with the STF remake board, it is a inherent design issue which has only just been realised on the STFM machines.

Main topic here.
https://www.exxosforum.co.uk/forum/viewt ... =19&t=1260

[exxos]

PARALLEL PORT FIX

Thanks to PaulJ for finding this one. https://www.exxosforum.co.uk/forum/viewt ... 100#p11919

A connection on IO4 was missing.. Simply solder wire is highlighted by the yellow line below..

ppp.JPG (167.74 KiB) Viewed 9461 times

[exxos]

VIDEO BRIGHTNESS FIX

3 Resistors are actually wrong 15K when should have been 2.2K... However 2.2K (what I had to hand) still seems to dim, so I suggest 1.8K as the replacement value.

Change R91,R92,R93 with 1.8K.

(2.2K in parallel with 10K will be 1.8K also, I will have to do this as I only have 2.2K and 10K values)

rgbfix1.jpg (127.47 KiB) Viewed 9445 times