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I'm not really happy with the title. These things were mainframe emulators, not mainframes themselves. Is there a better name for this class of product? "PC-based mainframe emulators" might be better. Did any other mainframe company also make a desktop with the same instruction set? --Wtshymanski (talk) 16:56, 24 February 2011 (UTC)[reply]
Is it a mainframe emulator when the CPU runs the mainframe instruction set natively? The P/370 and P/390 processor boards did just that, even if you don't agree the XT/370 and AT/370s did. -- Jay Maynard (talk) 18:24, 24 February 2011 (UTC)[reply]
Well, it's running the instruction set, but isn't a "mainframe" defined by a lot more than its instruction set? The little desktop box huffing and puffing away at a 5 1/4 inch hard drive isn't doing anywhere near the sort of job the roomfull of racks is doing. What did IBM call this class of product? --Wtshymanski (talk) 18:51, 24 February 2011 (UTC)[reply]
Good question. IIRC, the P/370 and P/390 were called "personal mainframes", but I could easily be wrong, too. I do know the Multiprise systems were called mainframes with no qualifiers. -- Jay Maynard (talk) 04:35, 25 February 2011 (UTC)[reply]
Well, that wouldn't be the first instance of hype in the computer business, but it still sounds a little like calling a garden tractor a "personal locomotive". I wish the title was a little better but it has kind-of the right associations - running some types of mainframe software on a micro, even if it doesn't have the performance. I should ask myself "Is anyone going to seriously confuse the desktop box with the dinosaur pen?" - probably not. --Wtshymanski (talk) 14:18, 25 February 2011 (UTC)[reply]
OK, but compare to the bottom of the line S/360 or S/370 machines, such as the 370/115. I suspect that the P/370 is somewhat faster, and has a lot more memory, than a 370/115, the latter being called a mainframe. There are some (not me) that argue that any microcoded implementation is an emulation. Otherwise, the machines described here use the PC side for I/O, and the on-board processor for processing. As well as I know it, the IBM 303x machines use 370/158 hardware for the channel processor. Much of the time you try to make some distinction, you find a counterexample. Better to not try. (And if you do, it is probably WP:OR.) Gah4 (talk) 21:02, 3 October 2021 (UTC)[reply]
This article says nothing about the processor boards containing RISC processors but they did. I was part of a study to determine the value of the AT/370 for mainframe programmers. I remember them saying that the processor board had a RISC processor; I think a Power PC. I think but I cannot prove that IBM has been using RISC processors to implement their 370 and subsequent architectures for years. In about 1971 I was in an IBM branch office looking for manuals to purchase and I saw a manual about microcode. I asked if it was available and the woman went away and came back and said no, it is not available. It probably was the equivalent of the RISC programming of one of their 370 computer models. The processor board for the AT/370 was probably close enough to a real 370. Sam Tomato (talk) 02:00, 8 February 2018 (UTC)[reply]
The Mueller book says the AT/370 cards were the same as those for the XT/370, but *this* article says the AT/370 could do 16-bit DMA, an impossiblility for a card that fits in an XT slot. We need a citation for 16-bit DMA. --Wtshymanski (talk) 14:26, 25 February 2011 (UTC)[reply]
Definitely the AT/370 has a 16 bit bus and 16 bit memory access. As above, I think it depends on the meaning of "same". There is not a lot of difference between them, but bus width is one. The XT/370 bank switches 512K into 384K of XT memory, the AT/370 maps into 128K of AT memory. They use different look-up tables for virtual memory, too. But the actual processor chips are pretty much the same. Gah4 (talk) 21:12, 3 October 2021 (UTC)[reply]
The article appears to have confused the Personal System/370 (PS/370) with the Personal/370 Adapter/A (P/370). The article describes the P/370 as having been available to select customers in late 1989, citing a 1989-11 InfoWorld article that only mentions it in passing. This is consistent with "IBM 'personal mainframe' goes public this summer" (Juli Cortino, PC Week V. 6, No. 16, 1989-04-24), which describes the PS/370 (which is a renamed IBM 7437), but is inconsistent with "PS/2 may gain mainframe card" (Susan E. Fisher, PC Week V. 10, N. 30, 1993-08-02), which describes the P/370 MCA card. The article's description of the Personal/370 is also consistent with the P/370, but not the PS/370. 99Electrons (talk) 23:05, 9 March 2019 (UTC)[reply]
Parts of this article (those related to section) need to be updated. Please help update this article to reflect recent events or newly available information. Relevant discussion may be found on the talk page. (February 2014)
What a stupid template that is destroying Wikipedia slowly. The bastard who wrote that is too lazy to do anything to actually improve it, and 7 f'n years later, nothing has been done. I think the best thing those of us trying to actually improve wikipedia should shoot ourselves in the head. What a hopeless mess!