Path: csiph.com!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail From: Stephen Boyd Newsgroups: comp.sys.unisys Subject: Re: OS2200 MFD question Date: Mon, 13 Jan 2025 10:02:27 -0500 Organization: A noiseless patient Spider Lines: 62 Message-ID: References: <15bf6012a0c40cd4d60fe63663fced61@www.novabbs.com> <06147a0a-8adf-470f-8bd2-7a295db170bc@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Injection-Date: Mon, 13 Jan 2025 16:02:28 +0100 (CET) Injection-Info: dont-email.me; posting-host="95908b43977d66af398b6957db281f42"; logging-data="1924847"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1/jH/TTLFbMwUTufaafHZZobfM8Oth3+4Q=" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:o4G9yevvPseTKkag0Pjjx0Mt/yg= X-Antivirus: AVG (VPS 250113-2, 2025-1-13), Outbound message X-Antivirus-Status: Clean Content-Language: en-CA In-Reply-To: Xref: csiph.com comp.sys.unisys:2561 On 2025-01-12 1:49 p.m., lewiscole wrote: > Well, I could be wrong, but I suspect that the Exec won't allow a user > to arbitrarily look at anything on disk using a IOW$ or any other I/O > related ER. > From looking at an admittedly old version of MFD, this is exactly how it reads the MFD. It uses ER IOW$, reads sector 0 to get the pointer to the MFD and starts to read certain parts of the MFD into a temporary file. > Regardless of the reason, I'm pointing out that you may be violating the > terms of your licensing agreement which COULD (at the very least) lead > the Company to not renewing your PS2200 license if they wanted to. > That may not be a problem for you, but if you're interested in continue > to play around with it, it's a risk you should be aware of. > I guess that depends on how you define some of the terms. I have not reverse engineered anything. I have not decompiled anything. I have not disassembled anything. I have certainly not tried to execute any OS2200 code outside of PS2200. I wouldn't want to get into a legal argument with Unisys so perhaps I will desist from satisfying my curiosity in this matter. >>> Unfortunately, Univac/Sperry Univac/Sperry/Unisys (USUSU) has had a long >>> standing habit of making such old manuals disappear and so I suspect >>> that it will be virtually impossible for you to find such a manual. >> >> Very true. I have an old version of the Data Structures manual and there >> is a lot of stuff in there that isn't in the new one. There are problems >> with even the old manual though. First, it assumes a level of knowledge >> of Exec internals that I simply don't have. [...] > > The Exec is a proprietary product and I doubt that the Company is going > to release its source, and the Company clearly doesn't want users to > find out how things work internally on their own. I can't argue with that. If I were trying to make an emulator to run OS2200 I can see where they would be upset. But that is not my goal and like I said I don't need any conflict with Unisys' legal team so ... > > Well, I could be wrong, but I suspect that the Exec's file system isn't > something that is going to change much without a very good reason. > Some things like using TDATE$ format dates need to change. > It could be a coincidence, but I can't help but feel that there's a > possible correlation between your having to subtract 18 (i.e. 2 * 9) in > order to get your addresses to work out. > It's just a thought. > I've wondered about the same thing myself but have been unable to come up with any logical reason for it. -- This email has been checked for viruses by AVG antivirus software. www.avg.com