This is not an answer as I don't know the real reason. It is just a comment about parsing label: In pascal varname: is expected to be followed by either = or a variable type. If a statement were ...

Can't really put a figure on it. I've had the same disk in a portable USB 3.5" drive for 5 years which I used for installing licence keys on numerous machines and uploading to a database. Doesn'...

To add to the above, there was a book that I had as a teenager, published in 1966 We built our own computers by A.B.Bolt et al. ISBN 9780521093781. You can view some of the pages here https://books....

In C, if a variable has "static" in front of it, it is private to the code module. If someone decides to stick it in a header file, then every source file that #includes that header file ...

Not an answer: just a silly story on trips and on/off switches. This happened in the early 80s. We used to have a VAX, and MV8000 and a few Data General Eclipses. One of the eclipses had a power ...

This is not for a serial port - it uses an ethernet connection. If you have one, it will be a lot quicker than a serial port. In addition the the methods described by @Spektre, you could also use ...

The only use I've see for USR commands is an anti-piracy system. The program downloaded sets a delay when writing a particular track. If that track is read normally, the red light starts flashing ...

The machine should work even when the battery doesn't work. Just remove the battery: it should be able to run directly from mains. You should be able to take the drive out and use it as an external ...

The 1966 ANSI standard X3.9-1966 ANSI standard (https://wg5-fortran.org/ARCHIVE/Fortran66.pdf) just says A GO TO assignment statement is of the form ASSIGN k to i where k is a statement label and i ...

For 8080, 8085 and Z80, possibly PL/M. That generated exactly what you told it. Also, it had special I/O instructions. With most other compilers, you had to call output(0x20, 0x90) but in PL/M it ...

I only have experience of ICL mainframes, CDC, Prime 300, Data General Nova and Eclipse. On those, the programs just crashed. Like Mick's answer, it would be up to the programmer to figure it out. ...

I used to have an exchangeable disk that I used between my PC and my kids' PC. Theirs was more powerful so when they were at school and I was working from home, I'd use their PC. The trick is to ...

Doesn't it really depend on how you draw your memory. ________ ________ FFFF| | 0000| | | map 1 |down | map 2 | ^ | | v | ...

It is basically any character that is not part of the syntax. There is no connection with parsing theory. It depends on the definition of what is being parsed. $ is usually used to reference the ...

Yes - C has been around since 1972 but there were no MS-DOS C compilers until the late 80s. To convert an entire OS from Assembler to C would be a mammoth task. Even though it might be easier to ...

As Jules said, SYS is the BASIC instruction to execute a routine in machine code. Very much like GOSUB. USR is the equivalent of DEF FN. There are 2 ways in which machine code is loaded It is ...

If you wish to use ethernet instead of serial, there is a program that was obtainable from MS at one time called MSWGCN.exe (Microsoft Workgroup Connect). It allowed a network to be set up on a DOS ...

Found a wiki article on it https://en.wikipedia.org/wiki/Software_protection_dongle Wordcraft were the first ones to use it but they didn't create the word dongle.

6.2 had a brilliant file transfer utility which you could work through either the parallel port or serial port and a crossover cable. On earlier versions, you had to use a Norton based tool. On the ...

Not really an answer but too long for a comment. If a floppy drive is out of alignment when writing to the floppy, any other aligned drive will fail to read it. It may or may not fail to read any ...

When I did this sort of thing years ago, I wrote the interpreter in a different language (like C or PL/M) and then used a cross compiler to generate the code and a bit of assembler to set the start ...

I remember doing this on the university mainframe around 1975. This was on an ICL1904S. Note that the 1900 series had been around for more than 10 years at that time. I don't know when the feature ...

The ferrite core memory system is quite reliable. When I was working on medical systems, we used pre-programmed systems in core memory. One day, we got a call from the factory in the US, saying that ...