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GRiD ethernet cartridge 34014

0xDEADBEEF

0xDEADBEEF

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Due to recent silly eBay purchase I came into possesion of an ethernet cartridge.

If you are like me you probably wondered whats inside and how does that work.

It is essentially reformatted Racal Interlan NI5210 https://theretroweb.com/expansioncards/s/racal-interlan-inc-ni5210-16-utp
It does use NI5210 drivers and MTCP worked with NI5120 packet driver set to I/O 300h, IRQ 5 (yes, sticker lied), ROM at C000.
Works with regular centrecom AUI transceiver.
Now, if someone can figure out what kind of connector this uses maybe someone skilled with electronics can actually make ISA cards like that for GRiDcases. PicoMem or PicoGUS would be great ;-)
eth1.jpgeth2.jpgeth3.jpgeth4.jpgeth5.jpgeth6.jpg
 
That is for sure an interesting design choice in having the "AUI like" signals go between the AUI "driver" PCB and the actual ethernet controller chip and whatnot via the computer the module sits in.

I wonder what the thought was behind that design? Do the computer provide some sort of docking station connector that it can switch in instead of the AUI port?
 
I don't think the AUI port loops back into the module by the front sockets. Note the pin header that it all routes to and then drops the the board below it.

Supposedly starting with the 1500 series you had a 16-bit ISA slot in the back of the battery compartment in the form of two funky headers. GRiD sold these ethernet adapters which are driver compatible with an Interlan card (yes mTCP will work with this!) but GRiD could also design custom pods you could plug-in instead.
Klyball has the manual hosted on his site - https://www.klyball.com/GriD/_GriD Ethernet Adapter Manual.pdf - Interestingly, this ethernet pod does not have the metal tab that interlocks the cartridge to the DC socket. It looks like someone cut it off.
 
the 2nd pcb with AUI only has some power converter, second slot smaller carries extended 16 bit ISA signals only so there is nothing AUI could use, i think it is just power. the ethernet card is pretty much 8 bit ISA otherwise.

yeah the interlock is gone. i think it was to prevent people from removing the cartridge when laptop was powered on
 
Neat cartridge. Expansion pod pinouts here, connectors are P51-040S-S1-EA, P51-040P-SR1-EA, P51-060S-S1-EA, P51-060P-SR1-EA. I was going to make a pod once but ended up just building an ISA slot riser for the internal header instead.
 
hmm i wonder what are the connectors on the motherboard that go into cartridge backlplane or ide/floppy backplane.
i think something like picomem/picogus design would easily fit into cartridge backplane pcb footprint without affecting ability to use cartridge power supply/battery
 
I think those are all AMP connectors (see AMPMODU System 50). Specifically part numbers 5-104068-6 and 6-487937-0 for the storage backplane but I used normal cheap 1.27x2.54 pitch non-latching connectors with long legs since my PCB was direct plug and secured with screws.
 
0xDEADBEEF said:
the 2nd pcb with AUI only has some power converter, second slot smaller carries extended 16 bit ISA signals only so there is nothing AUI could use, i think it is just power. the ethernet card is pretty much 8 bit ISA otherwise.

yeah the interlock is gone. i think it was to prevent people from removing the cartridge when laptop was powered on
Click to expand...

AUI (Attachment Unit Interface) is simply a means of separating the networking hardware from the hardware that handles the physical layer element of attaching it to a particular medium (10Base5, 10Base2, 10BaseT, etc).

https://en.wikipedia.org/wiki/Attachment_Unit_Interface (AUI)
https://en.wikipedia.org/wiki/Medium_Attachment_Unit (MAU aka 'transceiver')

That integrated circuit chip right next to the AUI connector is a Manchester Code Converter.

 
yes, and there is an AUI connector on the cartridge, works fine with tried and true centrecom. so this top pcb doesnt really do much. the bottom one is practically whole 8 bit ethernet card.
 
0xDEADBEEF said:
yes, and there is an AUI connector on the cartridge, works fine with tried and true centrecom. so this top pcb doesnt really do much. the bottom one is practically whole 8 bit ethernet card.
Click to expand...
Not much isn't the same as "not important", but yes the majority of the hardware is clearly on the lower board.

Intel P82586 -> IEEE802.3 ETHERNET LAN CO-PROCESSOR
Phillips 74HCT244, 74HCT245 -> probably doing bus interfacing ('244 -Octal Buffers and Line Drivers With 3-State Outputs, '245 - Octal Bus Transceivers With 3-State Outputs)
Phillips 74HCT157 -> maybe handling alternate 8-bit pieces of 16-bit data? or possibly controlling whether data goes to th big chip on the left or to the Ethernet LAN co-processor ('157 - Quad 2−Input Data Selectors / Multiplexers)
RCA 74HCT373, 74HCT374 - > Not sure what these are doing ('373 - Octal Transparent D-Type Latches With 3-State Outputs, '374 - Octal Edge-Triggered D-Type Flip-Flops With 3-State Outputs)

National SCX6212SCC-V4 -> this chip is a mystery to me, but it must surely be handling the communications with the computer and is probably a micro-controller (SC/MP related?) or quite a pile of complex logic.
 
From my research National SCX6212SCC-V4 is kind of early FPGA type of thing.
 
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