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I get you point. I was speaking in relative terms about it being "general purpose" and probably should have instead said "that can run an program from an external ROM"...and it that aspect it is more "general purpose" relative to the TMS 1802NC which could only run a fixed program burned into its internal rom. Nevertheless, while it is unsuited for running a general-purpose processor, it has indeed been proven to be capable of running Linux (albeit by emulating MIPS).

For what it is worth, Intel does refer to the 4004 as the "first general-purpose":

"That’s when the Intel® 4004 became the first general-purpose programmable processor on the market—a "building block" that engineers could purchase and then customize with software to perform different functions in a wide variety of electronic devices." https://www.intel.com/content/www/us/en/history/museum-story...

"The 4004 would replace that system with a general-purpose chip that could be mass produced and then programmed through its software to perform specific functions, such as those of a desktop calculator. That idea could make computing cheaper, more powerful and smaller in one fell swoop. It could, in other words, facilitate the modern information age. In 1969, the Nippon Calculating Machine Corporation approached Intel to design 12 custom chips for its new Busicom 141-PF printing calculator. Intel's engineers proposed a new design of just four chips, including one that could be programmed for use. That programmable chip, later known as the Intel 4004, became the first general-purpose microprocessor." https://www.intel.com/content/www/us/en/history/virtual-vaul...

What they say now is irrelevant, because it is retconned with the purpose of increasing the apparent importance of what they have done in 1971 vs. what they have done in 1972.

Moreover, you can be pretty certain that whoever has written that text has never read the datasheets of Intel 4004, to be able to evaluate whether it was "general purpose" or not.

Even at its launch in 1971, when Intel has begun to offer for sale the 4004 because Busicom was unable to pay the price desired by Intel for 4004, the Intel marketing has attempted to present the 4004 as much more general purpose than it really was, in order to find customers for it, in order to ensure the profitability that could not be provided by Busicom.

During its design, 4004 has never been intended to be general-purpose, because the plan was to sell it to a single customer. Only after the delivery to the intended customer the Intel marketing has made great efforts to find other possible applications for it.

Inexpensive personal computers weren’t shipped with EPROMs, they were shipped with mask programmable ROMs. EPROMs were used in development but they were nowhere near as important as the microprocessor.

Mask programmable ROM could be used only by the companies whose production of computers had grown enough to make them worthwhile.

Moreover, in the beginning Intel was also the main producer of mask-programmable ROMs, which were launched at the same time with the corresponding EPROM, with the 23xx mask-programmable ROMs corresponding to the 27xx EPROMs.

All these part numbers belonged to a system used by Intel, where the first digit was "1" for PMOS, "2" for NMOS and "3" for bipolar, with the second digit being the kind of IC, e.g. 21xx for RAM, 23xx for mask-programmable ROM, 27xx for UV-EPROMs and 28xx for electrically-erasable PROMs.

Other manufacturers have started the production of memories after a delay of a few years and most of them have made memories compatible with those introduced by Intel and they have kept the 23xx and 27xx Intel part numbers.

Didn’t PROM come before EPROM? While I agree EPROM enabled easier testing, PROMs would fit the bill once their contents got stable.

Bipolar PROM was too small to contain the equivalent of the BIOS of a computer in the early seventies.

Bipolar PROMs were initially used mainly to store microprograms for CPUs with microprogrammed control and for implementing various kinds of programmable logic, in which role they were later replaced by PLAs, then by PALs.

I do not think that there has ever been any kind of computer that has stored in bipolar PROMs programs that were usable during normal operation, except perhaps some kind of embedded controllers designed before microprocessors become widespread, together with their associated EPROMs.

By the time when the Intel EPROMs like 1702 and 2708 have appeared (with a capacity of 256 bytes, then of 1 kbyte), typical bipolar PROMs had capacities of either 32 bytes or 128 bytes.

In that space you could put at most some kind of initial loader that would load a real bootstrapping program from something like a punched-tape reader. This kind of solution was used in some minicomputers, replacing the introducing of such an initial loader from console keys, by the operator. Such minicomputers were still at least an order of magnitude more expensive than the first computers with microprocessors, mainly due to the expensive peripherals required for a working system.

The Apple I had a single 256 byte bipolar PROM for its WozMon debugger. Though the Apple II used ROMs (EPROMS were popular in clones) the expansion cards still were supposed to use tiny PROMs for their drivers (in the case of the disk controller there was even a second PROM for the state machine - Woz did love these devices).

The Altair 680 had sockets for four 256 byte PROMs. One was for the debugger, but a popular option for the other three was the VTL-2 (very tiny language) interpreter. Pretty amazing that they fit a Basic-like language in just 768 bytes, though implementing some language in the 510 byte boot sector has become a popular hobby.