Xtra PC - a bit tecchy

[Constantbee]

as we appear to be in our anecdotage - anyone else ever programmed a PDP1 or a DDP516 (the big brother to the H316 which ran the original ARPA nodes) - the 516 actually had in late 60s a hard drive - 2MWords (4MByte) powered by a probably half horse power motor in a cabinet maybe 1m square by 200mm

er ... nooooh ... but tech like this is starting to appear in computing museums that are mushrooming up around the globe as we speak. There's a lot of interest in restoring old hardware like this and a lot of people have a lot of affection for it. Quite rightly, too, imho. Here's an example of the PDP1 from the Computer History Museum at Mountain View CA:

https://www.computerhistory.org/pdp-1/

There's a control unit for the (Honeywell) DDP 516 computer (1966-1970) at the Science Museum in London. Donated by a school in Kent.

[Frances_iom]

my first home computer (early 70's) is in science museum reserve collection as the company I consulted for and who bought the first batch of production of a British built desktop (based on a 68000) put together working model when asked by the science museum and I donated mine to help in rebuild,

I wrote as my 1st foray into assembler a simple program load system for the 516 to ease matters as generally we used paper tape with 2 copies of program thereon as assembler was a two pass assembler - this served for several years as a sort of bios - the bootloader needed to set in by setting the 16 keys to directly imput the boot code.

[Dave2002]

er ... nooooh ... but tech like this is starting to appear in computing museums that are mushrooming up around the globe as we speak. .

Not sure if I'll be put in a computer museum ......

Just using this as a test for the Live Ubuntu system I "just" installed on a MacBook AIr. It was a bit of a faff, and took over 2 hours to get up and runnimg, connected to internet, and exploring the interface. The Live Ubuntu system seems very very clunky - but I assume it's running off the USB memorystick. I'm not quite sure what happens if I "install" it - does it get put on the host computer, or on the memory stick?

I suppose I could try, but I don't want to have to remake the OS if things go wrong. I have another possibility, which is to run the Ubuntu disc image on the host computer via Virtual Box, but I don't know if that would be any faster. I have done that sort of thing before, but it can be a bit hit and miss.

[MrGongGong]

Not sure if I'll be put in a computer museum ......

Just using this as a test for the Live Ubuntu system I "just" installed on a MacBook AIr. It was a bit of a faff, and took over 2 hours to get up and runnimg, connected to internet, and exploring the interface. The Live Ubuntu system seems very very clunky - but I assume it's running off the USB memorystick. I'm not quite sure what happens if I "install" it - does it get put on the host computer, or on the memory stick?

I suppose I could try, but I don't want to have to remake the OS if things go wrong. I have another possibility, which is to run the Ubuntu disc image on the host computer via Virtual Box, but I don't know if that would be any faster. I have done that sort of thing before, but it can be a bit hit and miss.

I know folks who do double (and triple) boot.
That works for OSX/LINUX/WIN etc

Why not do that?

[Dave2002]

I know folks who do double (and triple) boot.
That works for OSX/LINUX/WIN etc

Why not do that?

Thanks - yes I've done that before. It would work on the particular machine (not mine) as there is enough space, but whether the user would want to have a permanent Bootcamp start up I'm not sure. I suspect not, unless it was absolutely necessary.

I have made workable and bootable copies of MacOS before now on USB sticks, and if I could be sure that I could do that without other problems, that might be the best option - if this is going to be a long term requirement. Slightly worrying was the warning which appeared in one of my trials yesterday, warning me that installing the Linux system would erase everything. That would be OK if I knew exactly which drive it was planning to erase - if it was the USB stick, but if it erased the main computer hard drive - although it wouldn't be a complete disaster - it would be to say the least "very unfortunate", and a PITA. I could protect against that by making yet one more bootable copy of the system on that machine, but it's all a lot more work, which I'd probably prefer not to have to do.

As part of the motivation for attempting the creation of the USB system yesterday was to overcome a problem with Apple's assumption that it knows more about how I want "my" data to be handled than I do, I have now made a discovery that I can probably avoid the problems of using Apple's mail client and address book by using Thunderbird, which seems at least to have the decency to not assume automatically that any email ids it sees are up for grabs, and to be stored in an address book, or in a cloud.

Having got this far with the USB stick, I may continue with it further out of interest. I wonder if the stick will now work on some old Windows laptops we have - even though it was made on MacOS. It probably should, though might not. It could be useful if it could work across several computers, and if the performance was reasonable. However, it seemed very clunky on the two Mac machines I used yesterday, with mouse/trackpad movements being very hard to get right - so almost unusable because of the poor interaction. The other option of using Virtual Box is also quite interesting - and may be better. However now we have perhaps found a solution to the original problem, exploring these options is more a matter of curiosity now, rather than necessity.

Incidentally - just for clarification - the suggestion/query about the Xtra PC which initiated this thread was not, in fact, triggered by the particular email problem which came to the surface very recently, but since a situation arose where that might have been useful, I thought to check a bit further. IF the Xtra PC does work as claimed, and has a good enough performance, and IF it's cheap enough, then it might still save a considerable amount of time as doing all the work and testing using memory sticks which one might just happen to have lying around, can easily take several hours, as I verified last night. This is not a recommendation for the Xtra PC as I don't know how well it does, but simply an observation. It might be a reasonable buy, but I still don't know.

[TRAVELLER29]

I recently received and installed Xtra PC which worked well at first then after about 3 weeks of constant use I was locked out.It suddenly
requested my password which I had not installed.Icannot find answer to how to overcome this problem. Any suggestions please?

[Frances_iom]

if it is a Mint/Ubuntu derivative it is designed to request a password only if admin tasks are required, with no root (ie superuser) user that has login credentials - I presume you have tried just hitting return at the prompt (ie a null password) - if this doesn't work then it depends somewhat on what medium you installed the system and if you have another bootable device as the approach is to edit the existing system by clearing the root password - typically a system restore CD is used (the Admin computer mag tends to issue these about 1/year) tho any bootable linux that runs from a cd and has access to the media on which you installed the system will suffice - lookup " linux clearing root password" for various options.

[Beresford]

I wrote as my 1st foray into assembler a simple program load system for the 516 to ease matters as generally we used paper tape with 2 copies of program thereon as assembler was a two pass assembler - this served for several years as a sort of bios - the bootloader needed to set in by setting the 16 keys to directly imput the boot code.

My foray into assembler, in the 70's, was to write an assembler subroutine to a Fortran program on a PDP-11. With no experience, it took me a week to write a working 10 line routine. Never again, but at least it taught me what computers actually do (mapping and memory). And I still suspect that Windows (and Symbian?)machines, at the most basic stripped down level, sound slightly nicer than the Unix/Linux/Apple/Android PC's, probably down to the different way they do multitasking.

[Dave2002]

My foray into assembler, in the 70's, was to write an assembler subroutine to a Fortran program on a PDP-11. With no experience, it took me a week to write a working 10 line routine. Never again, but at least it taught me what computers actually do (mapping and memory). And I still suspect that Windows (and Symbian?) machines, at the most basic stripped down level, sound slightly nicer than the Unix/Linux/Apple/Android PC's, probably down to the different way they do multitasking.

I don't see how you can make that assertion about Win PCs vs Apple - most of the machines nowadays surely do multitasking and multithreading in pretty similar ways. If you wanted, you could make most of the machines dedicated to music reproduction, and strip out all other processes - and if you really wanted you could no doubt write your own system with hardly any interrupts or whatever else you feel might interfere with the sound quality.

Currently one of our resident (former?) experts on such matters has gone incommunicado - so sadly we can't have her views on this.

I do agree with you that writing in assembler/machine code is a painful exercise, and hopefully not needed these days - at least for most of us.

I once wrote a tape conversion utility in assembler for an ICL machine - and by tape I mean the kind of data tape which was used about 45 years ago for bulk storage. I seem to recall I also wrote parts of an ICL operating system, which probably never saw the light of day, and that gave me ideas of how to write code as if the underlying machine was virtual. Rather than write code directly the programs were coded using application specific codes, which could then either be compiled (converted to machine code) or interpreted. This was commented upon at the time as an interesting way to write code, as it was easy to understand, and document, and easy to recode if necessary, and in a development team, errors often crept in through poor documentation, and lack of understanding and insufficient adherence to programming standards.

[Dave2002]

I recently received and installed Xtra PC which worked well at first then after about 3 weeks of constant use I was locked out.It suddenly
requested my password which I had not installed.Icannot find answer to how to overcome this problem. Any suggestions please?

Are you still stuck on that? Maybe if you contact one of the Linux forums or magazines they would be able to help.

[Frances_iom]

Are you still stuck on that? Maybe if you contact one of the Linux forums or magazines they would be able to help.

if your machine has a CD then set the CD to be the 1st to boot (via the Bios - access to which depends somewhat on your machine but usually something like holding down escape or delete whilst booting) then insert a bootable CD for any linux then use google or duckduckgo to find out how to reset a lost root password as it is likely that others had found the same problem. These bootable CDs are usually found within any linux mag or you may have one already.

[Dave2002]

Here is some "advice" based on Ubuntu - https://askubuntu.com/questions/2400...lt%20%2B%20Del

I don't guarantee that any of this will work.