On Thu, Apr 21, 2016 at 7:52 PM, Guy Sotomayor <ggs at shiresoft.com> wrote: Are you sure, the IBM S-100 system was demoed only in Europe, I assume developed there too. I know of the S-100 cards with IBM mincomputer memory that also eventually appeared in early RAM cards for the 5150. Here is an example: http://vintagecomputer.net/ibm/5155/ibm_256KB_memory_card_6407740.jpg -- @ BillDeg: Web: vintagecomputer.net Twitter: @billdeg <https://twitter.com/billdeg> Youtube: @billdeg <https://www.youtube.com/user/billdeg> Unauthorized Bio <http://www.vintagecomputer.net/readme.cfm>

On 4/22/2016 11:02 AM, Guy Sotomayor wrote: Link? -- Jim Brain brain at jbrain.com www.jbrain.com

On Sat, 23 Apr 2016, william degnan wrote: 1.25 would be MS-DOS. The PC-DOS equivalent was 1.10 ("equivalent", NOT exactly the same (GWBASIC, MODE.COM differences, IO.SYS/IBMBIO.COM differences, FORMAT, DISKCOPY, DISKCOMP differences)) MS-DOS 1.25 could be configured by OEM for various disk formats. At that time, MS-DOS was not available for direct retail sale. "Only available from computer OEM". OEMs could sell it retail to buyers of their computers, and theoretically ONLY to them. In reality, few OEMs wanted to, nor bothered to, confirm "legitimacy" of their customers, and many OEM copies found their way to retail sales. ("gray market") In fact NO version of MS-DOS was legally retail until 5.00. MANY OEMs let out "OEM" MS-DOS for retail sale by third parties. PC-DOS 1.10 was 160K and 320K ONLY. Many OEM versions of MS-DOS 1.25 (such as Compaq) deliberately lockstepped with IBM, and did not offer any diverging capabilities. For many of those OEMs, the main thing that they had to offer was a [cheaper] way to get a 5150, with possibly some clever developments. 1.25 could NOT have been demoed in Europe, nor anywhere else until 1982, well after the 5150. HOWEVER, it is entirely possible that that "IBM S-100" was merely a Seattle Computer Products S100, or even an SCP 8086 CPU board in a Cromemco S100 system, with a piece of tape changing the name. (In order to "test the waters' about how an IBM 808x machine would be received?) 1.00 came out in August 1981. PC-DOS 1.10 came out in May 1982. MS-DOS 1.25 came out in June 1982. The existence of later versions AFTER the first one, does NOT "hint at a time when there was a DOS in development floating around before" the first one. Existence of a later version never hints at presence of something before the first one, although CONTENT might give some clues of what was being considered at various times. It hints at further development, and the possibilities of spreading out into areas where IBM did not tread. But, YES, the very first version WAS for an S100 machine made by Seattle Computer Products. Written by Tim Paterson, it was called "QDOS" (Quick and Dirty OS), and then "86-DOS". (and, for a while, "SB-86") YES, it supported 8". Then, in July 1981, SCP sold it to Microsoft, who handed off to IBM. Microsoft's contract permitted them to sell it to other computer OEMs, but ONLY through other computer OEMs. THAT restriction ended in 1991, commemorated with MS-DOS 5.00. After Microsoft upgraded PC-DOS from 1.00 to 1.10, they then provided computer OEMs with a similar product numbered 1.25 OEMs were expected to make their own personalized and customized IO.SYS, MODE.COM (could also do stuff such as switching between internal/external monitor, etc.), etc. OEMs did not even need to call it "MS-DOS" (Zenith Z-DOS) Trivia: there was no one point one. it was one point ten. Internally, the minor version of the OS was stored as a two digit decimal number, obviously stored in binary. Thus, "1.1" was stored as a 1 and 0Ah. MOV AH, 30h INT 21h returns major version in AL, minor in AH. "1.1" returns 0A01, 1.25 returns 1901, 3.30 returns 1E03, etc. -- Grumpy Ol' Fred cisin at xenosoft.com