EtherJet ISA 16-bit on a PS/2 model 25?

[EverythingIBM]

Hey Folks,

I was just curious if a 16-bit IBM EtherJet card would work in a PS/2 model 25 (which is only 8-bit ISA of course):

I guess I could always try it out, but the model 25 is stowed away until I get room to set it up. Also awaiting a SB 2.0 for it -- found a cheap one for $40.

 

[luckybob]

if its anything like the very similar 3com version... then no. I had to buy a parallel <> ethernet for my M25.

 

[EverythingIBM]

if its anything like the very similar 3com version... then no. I had to buy a parallel <> ethernet for my M25.

While they may look slightly visually similar, the etherjet cards don't use any 3com chips. But it's good to know that the etherlink IIIs are 16-bit only.
Guess I'll just give it a shot and find out later

I have a feeling it'll be 16-bit only as well-- just given how many traces on the 16-bit extension are going back to the IBM etherjet chip.

 

[luckybob]

If it was just the Irq lines then usually it will work 8-bit so long as you use 8-bit setup. That said, give it a try. I can't imagine it will hurt anything.

 

[modem7]

The manual for some other IBM 16-bit Ethernet cards is [here].
There may be some information in that manual that also applies to your card (see appendix B).

 

[Chuck(G)]

I believe that the Etherjet ISA cards use either the Crystal CS8900 or CS8920 chips. That being the case, your answer is probably "no". These chips start off with a 16-bit interface. While it's possible to do 8 bit DMA transfers to them, data must be aligned to a word boundary. Nothing in the datasheets about doing programmed I/O in 8 bit bytes.

There's a ton of information in the CS8900 and CS8920 datasheets (each runs to about 120 pages and even has PCB layouts and component lists).

 

[mbbrutman]

I would get the utilities loaded and just try it out. Other variants of the IBM Etherjet cards advertise compatibility with 8 bit ISA.