486DX2-66 a common computer? When was that. Like in 1993, 1994, 1995?
Probably... See, the thing is that both 386 and 486 were very expensive computers, so around 1990-1992, people would get 286 or 386SX machines.
After that, prices came down very quickly. As a result, I've rarely seen any 386DX machines with consumers. Most consumers made the jump to 486 right away, as did I (from a 386SX-16 to a 486DX2-66).
In "my area" I hardly remember seeing a 386 chip that was made by Intel.
That would be very odd, given that Intel has been supplying 386 CPUs since 1985, and AMD only from 1991 onwards.
Perhaps even more so for 286 chips maket which was quickly conquered by clone makers (AMD, Harris, IBM, Siemens).
Those aren't clones. Those are second-source Intel CPUs.
On the flip side. Back then it was common for many OEMs to not advertise AMD brand even if they actually used AMD chips.
For 286 and earlier it was irrelevant, since they were second-source Intel CPUs.
In 1991 Intel initialised "Intel Inside" campaign to promote brand loyalty just because of this.
The full story there is that Intel never second-sourced the 386 and later CPUs. AMD felt that they were entitled to clone these CPUs based on the earlier second-source contracts. So AMD reverse-engineered Intel's CPUs, and wanted to sell clones.
Intel sued, managed to block AMD from selling their clones, and AMD actually lost that claim: court ruled that the second-source license did in fact NOT entitle AMD to clone Intel's CPUs (more specifically: their clones violated Intel's copyright on the microcode).
However, the court also ruled that because x86 was such an important ISA worldwide, that Intel must allow third-party licenses.
In 1991 this court case came to an end and AMD could finally start selling their clones (after replacing the microcode with their own reimplementation).
From then on, AMD could actually market their CPUs as Am386SX/DX and Am486SX/DX, as these were products independent from Intel (where the second-source were just Intel CPUs manufactured in third-party fabs, much like how AMD and NVIDIA do not make their own GPUs, but have them manufactured by companies such as TSMC. This was actually not Intel's choice, but IBM forced Intel when they chose the 8088 for their PC, because IBM wanted to avoid the risk of being dependent on a single supplier. By the 386, Intel was much larger, and IBM had become irrelevant amongst all the clone builders, so Intel no longer honoured IBM's second-source requirement).
This led Intel to introduce the Intel Inside campaign, to distinguish their CPUs from the clones. Intel also moved from using model numbers to using model names, starting with the Pentium. The reason for this is that they could not trademark 386 or 486, but they could trademark Pentium. So that meant that clones could no longer use the same product names.