IBM PC 5150 and IBM PC XT 5160 FAQ

[rmay635703]

I use that hole in the 5150 to snake out cables.

Mine has an external little narrow box/bracket that snake through there off the multi-function card with clock that sort of just hangs off the sheet metal sandwiched by the case cover, gives me an LPT and game port on the top edge of the rear of the case, even has a grommet in that hole

 

[jimpqfly]

Hi. I have 3 x 5160 (don't ask..) and two of them have an AMD CPU. Is there any rule on having Intel vs AMD CPU on this model ? (Sorry for the bad english, I'm French)

 

[sorphin]

Hi. I have 3 x 5160 (don't ask..) and two of them have an AMD CPU. Is there any rule on having Intel vs AMD CPU on this model ? (Sorry for the bad english, I'm French)

Not that I'm aware of. I've seen both of them in use.

 

[RetroAND]

Hi. I have 3 x 5160 (don't ask..) and two of them have an AMD CPU. Is there any rule on having Intel vs AMD CPU on this model ? (Sorry for the bad english, I'm French)

Actually it was in those times that AMD and intel were in good terms, until the 8087 was released and AMD was pissed. Still, they continued to have their cross-license agreement for some time.

 

[JimA1]

IBM had a long standing policy to have at least two suppliers of its chips. So when IBM signed an agreement with Intel to supply the 8088 for the IBM PC, it insisted that Intel second source it to another manufacturer, which led to Intel selecting AMD to second source the 8088 and the 80286. Intel terminated the second sourcing agreement with AMD prior to the 80386. Jim

 

[jimpqfly]

Thanks for the explanations guys

 

[RetroAND]

Hello,

Usually there would be a question here, but actually the answer came before, so it will be self-answered in the same post.

Why did IBM ditch the DRAM controller and go for a PIT+DMA approach?

The answer, according to Dr. Bradley is because the team of engineers at IBM found a bug in the Intel 8202, which sent the chip makers back to the design stage. The PC project couldn't be delayed so they proceed to the design of the 5150 without such compnent, which gave the opportunity to one of the engineers to come with the combination we do know today. However, this statement has some implications as it shows originally the PC would have had a DRAM controller like the Datamaster had before it.

I hope this information could be useful to somebody, as as far as I don't know there was no motivation given for this change between both systems.