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NFX Hardware description

Posted: 29 Aug 2020 19:06
by Martin A
The first NFX used a WIZ811MJ network module, which used a W5100 self contained TCP/IP controller.

The updated version uses the newer WIZ810SMJ, which has the W5100S fitted. http://shop.wiznet.eu/modules/io-modules/wiz810smj.html

The new module is half the price of the old one (typically around a tenner). The test boards are the absolute minimum required to get the "net" up and running. Andy's NFX software works with either, as the major difference between the 2 wiznets boards is the removal of the umused (by NFX anyway) memory mapped mode.

There is one 8k rom image, which is running a modified CPM BIOS using the VDP for a 40 column display. The CF is connected an 8 bit IDE interface on the same I/O ports as CFX-2. The only other components on the board are a 74HC138 doing the I/O decode for IDE and Net and a 3.3v LDO to power the net module.

There'a no circuit diagram as such, however the wiring map I used for construction is in with the pictures below. The 8 bit IDE interface uses ports B0 to B7, and the W5100 uses 4 ports A0 to A3,(those are shadowed on A4 to A7 due to decode limitations). The actual connections for the IDE and Net module are very similar.

The Jumper on the test board would allow thu use of ports 90-93 instead as that wa sone of Andy's suggestion to avoid the I/O clash with Rememorizer's floating point hardware. Theoretically the NFX code should run from any MTX filing system, it's not restricted to CF, CF just happens to be easy top build for.
Screen grab of the excel wiring map - rear view
Screen grab of the excel wiring map - rear view
NFXscreen grab.jpg (84.81 KiB) Viewed 710 times
V2 Board
V2 Board
Version2.jpg (99.19 KiB) Viewed 710 times
Minimal Hardware.jpg[/attachment ][attachment=1]Solder Side.jpg

Re: NFX Hardware description

Posted: 30 Aug 2020 14:56
by 1024MAK
NFX-Wiznet WIZ810SMJ draft schematic
NFX-Wiznet WIZ810SMJ draft schematic
NFX-Wiznet WIZ810SMJ draft.png (129.79 KiB) Viewed 695 times
Mark

Re: NFX Hardware description

Posted: 30 Aug 2020 14:57
by Dave
Well done - that's one job off my "to-do" list :lol:

Re: NFX Hardware description

Posted: 30 Aug 2020 15:04
by 1024MAK
It’s only a draft. I’ve not added many decoupling capacitors or the 3.3V LDO voltage regulator yet.

Also it would be helpful if the pin-outs of the CF and the Wiznet be checked by someone who is actually awake please.

Mark

Re: NFX Hardware description

Posted: 30 Aug 2020 21:46
by Martin A
Looks pretty good to me.

The Wiz module has the pins labelled underneath, slightly blury photo attached for confirmation.
pins.jpg
pins.jpg (44.83 KiB) Viewed 682 times

Re: NFX Hardware description

Posted: 01 Sep 2020 09:15
by Bill B
The important information as far as I am concerned is that the W5100 is connected directly to the Z80 in "indirect bus mode" at the following Z80 ports:
  • 0xA0 - Mode register
  • 0xA1 - Address high
  • 0xA2 - Address low
  • 0xA3 - Data