The IBM System 360 Model 30
The IBM 360 range was announced on April 7th 1964, and the Model 30 was the baby of the line.
It was developed by IBM's General Products Division at Endicott (NY), and the first example was shipped in June 1965.
A long time ago (1982) I had one of these to play with. Unfortunately at that time I never took any photographs of the system, which consisted of:
- 2030 CPU (64k storage) + 1052 console (see picture at right)
- 2841 DASD (disk) controller
- 2311 disk drives (x 4)
- 2203 RJE station (300lpm printer + card reader)
- A serial interface to the 360 multiplexor channel for the 2203, which I designed and made myself
- All running DOS/360
Some years later I did a writeup on the trials and tribulations of getting this system working again which was lovingly preserved by Nigel Bree.
One error I should point out in the above document is that the microcode is not interleaved, and no attempt is made to overlap microcode fetches with execution.
It is also available in German thanks to Arno Kletzander.
In 2008 the console from this Model 30 was installed as a display at the Computer Science department of the University of Auckland
I am quite sure this computer is the one shown in the last photo on this page, arriving in Australia in 1966.
The Model 30 internals
Internally, the Model 30 uses 8-bit data paths and registers to provide the IBM 360 architecture. The main storage is arranged as 64k x 9bits (including parity). 16bit registers are used for storage addresses, but must be loaded 8bits at a time. The microcode is 4k x 55bits wide, with a cycle time of 750ns. For a fuller description of the internals of the Model 30, see the FETOM, which is amongst the IBM manuals accessible from the links page.
The Model 22
The /22 was a re-worked /30 fitted with 24k or 32k of semiconductor (MOS) memory. It was actually released after the announcement of the 370 series.
Model 30 Emulator
Select the VHDL link for a page concerning my 360/30 Emulator in VHDL.
Manuals I would like to get
I know that these are available on Bitsavers, but if anyone has paper copies they can spare, please let me know.
- C24-5022-4 Disk Operating System Operating Guide (Feb68)
- C24-3427-3 Disk Operating System Data Management Concepts (Feb68)