Bootleg 5161

[maxtherabbit]

There are open source clones of both the TX and RX cards from the 5161. I have an extra XT chassis and PSU with no system board. Thinking it might be a fun project to build these card designs and make a bootleg 5161 in a real 5162 chassis. I would finally be able to have enough slots to drive my 5151 and 5154 from authentic IBM EGA and MDA at the same time!

I will document this project on here if anyone finds it interesting. For now does anyone have a suggestion for a passive ISA backplane that will properly fit in an XT chassis?

 

[Lutiana]

I know the the guy who reverse engineered and released the "bootleg" design. In fact he made me one of the transmitter cards for me, which works with my 5161 chassis and receiver card (he borrowed them for testing). So what you want to do is pretty easy to do.

I believe any passive backplane would work. The 5161 chassis is basically a 5160 chassis, which has the standard AT ISA spacing.

 

[maxtherabbit]

I know the the guy who reverse engineered and released the "bootleg" design. In fact he made me one of the transmitter cards for me, which works with my 5161 chassis and receiver card (he borrowed them for testing). So what you want to do is pretty easy to do.

I believe any passive backplane would work. The 5161 chassis is basically a 5160 chassis, which has the standard AT ISA spacing.

The 5160 chassis did not fit several late AT-style motherboards (pentium era) that I tried to install in it. I don't think the screw/standoff spacing for XT and AT clone boards is the same, however many AT-style boards do have some or all holes for both.

 

[Nevets01]

I know the the guy who reverse engineered and released the "bootleg" design. In fact he made me one of the transmitter cards for me, which works with my 5161 chassis and receiver card (he borrowed them for testing). So what you want to do is pretty easy to do.

I believe any passive backplane would work. The 5161 chassis is basically a 5160 chassis, which has the standard AT ISA spacing.

You might need some extra circuitry for a clock.
From the GitHub page:

It works perfectly with various passive ISA backplanes! There is one slight catch--the 14.318MHz ISA bus clock signal is generated on the IBM backplane but not typically on passive ISA backplanes. Not all cards need this signal, however.

As for backplanes, Sergey Kiselev has one that should work, though it doesn't have that clock signal, and fitness is up in the air.

 

[maxtherabbit]

I can spin up a clock circuit on an ISA card if needed, really more concerned with having a backplane that fits properly without any bodge nonsense

 

[Exceter]

Where is the github page?

 

[maxtherabbit]

Where is the github page?

https://github.com/schlae/ibm-extender

 

[ctrl-alt-rees]

Funnily enough I was looking into the 5161 just today. The 5150 just doesn't have enough ISA slots for all the stuff I want it to do!

Definitely interested in following your progress on this one, sounds like a great project. :thumbsup:

 

[Lutiana]

Funnily enough I was looking into the 5161 just today. The 5150 just doesn't have enough ISA slots for all the stuff I want it to do!

Definitely interested in following your progress on this one, sounds like a great project. :thumbsup:

I can attest that if you have a 5161 with just the receiver card, then Tubetime's transmitter card will definitely work.

 

[mtrahms]

Has anyone actually put together a bootleg 5161? If so, were there any unexpected hurdles?

 

[bobconan]

What exactly do the Receiver and Transmitter cards do? Signal Amplification? Buffering? What if a ribbon cable was used instead of a round one? I've seen ISA extender cables, what is the limit to how long the cable can be?

Also, I believe Sergey's backplane only has holes for ATX.

 

[modem7]

What exactly do the Receiver and Transmitter cards do? Signal Amplification? Buffering?

Answered in the 'Extender Card' and 'Receiver Card' sections of the IBM document at [here].

What if a ribbon cable was used instead of a round one?

I.e. Unshielded. Certainly, the FCC accreditation would be compromised . (RF interference to other equipment.)

 

[lyonadmiral]

I'd like to know what would happen if you add more than 1 extender card as if you wanted to add more than 1 expansion unit? You probably can't, but wouldn't that be fascinating if you could?

 

[Agent Orange]

The 5160 chassis did not fit several late AT-style motherboards (pentium era) that I tried to install in it. I don't think the screw/standoff spacing for XT and AT clone boards is the same, however many AT-style boards do have some or all holes for both.

Just to add chaos to pandemonium, why no try some metalsmithing? Maybe a soul could take the metal AT/ISA card backet assembly and cobble that to the existing 5160 chassis. That would eliminate your card spacing issue. A Dremel might come in handy. Okay, I'll go back to my JD Black and coke.