The IBM 7000 series computers
The IBM 7000 line of computers spans many different models. They were all eventually replaced with the IBM 360 and 370 series. They span the tube/transistor changes also. All machines in the series used signed magnitude arithmetic.
Most of the 7000 line used BCD characters.
The first in the series was the IBM 701, also called "The Defense Calculator". The machine had 2048 words of elector static memory. Each word was 36 bits. Instructions where 18 bits long.
The IBM 704 had many firsts, it was a 36 bit machine like it's predecessor, but used 36 bit instructions. Memory size was up to 32K words. It also added 3 index registers (first use of them), and floating point instructions. It also allowed for subroutines to be written with little problem. The 704 was enhanced into the 709 adding indirect addressing and I/O channels. Converted to transistors as the 7090. And later became the IBM7094. IBM also developed a tranisterized version of the 704, which was called the IBM 7040 and 7044. These machines were a cross between the 704 and 709. They had simpler channels, and lacked the indicator register of the 709, but included double precision floating point of the 7094. They were also not as fast as the 7090.
The 702 developed into the IBM 705 and later was transistorized as the 7080. Memory sizes ranged from 10,000 characters up to 160,000 characters on the 7080.
Also in the line was the IBM 7070, 7072, 7074 this was suppose to be a transistorized version of the IBM 650. The machine never was very popular. All memory was 10 digit numbers with three possible signs, +, - and alpha. Memory sizes were from 10,000 to 40,000 words. It also used the first 100 words of memory for index registers.
Kind of as a after thought IBM decided to enhance the IBM 1401 and improve performance, be cleaning up the mess that the instruction set had become. This they called the IBM 1410. This machine like the 1401 had not registers, but operated out of memory fields. Wanting to charge the higher rental rates IBM made some changes and developed the IBM 7010 by doubling the processing throughput. Also it offered floating point arithmetic and 2 additional channels as options.
During the development of the IBM 704, IBM developed a supercomputer, perhaps the worlds first. The IBM 7030 aka "Stretch". Few were ever sold. After IBM got the machine working, they determined that they could not make the machine for the amount they had promised to sell it. So they only made machines for the customers who had preordered it. But much of the technology used to develop the Stretch found it's way into the IBM 709 and 7090 and later into the IBM 360.
Simulators for all these machines (except the 7030) can be found here https://github.com/rcornwell/sims. Eventually this will be merged into the main simH tree. Be sure to check the status of the current simulations, before trying them. See the various computer pages for software packages for them.
Note all software provided here for the IBM 7000 series machine is provided
free of charge. Since there was no copyright notice on it, it is provided
for free use. Generally IBM software for machines of this time was provided for
the cost of a magnetic tape. Also the restoration of this software has been
performed by many volenteers, working with old tapes. So please do not charge
for this software. If you have any software for these machines that is not
listed here, please contact me to make it available to larger community.