Honeywell 200

The Liberator marketing campaign exploited this compatibility, and was credited in later Honeywell publicity statements with stalling the sales of IBM 1401 machines.

[10] Honeywell claimed an initial rush of hundreds of orders for the H200 that itself stalled when IBM countered[11][12] with a marketing emphasis on their System 360 product range that was then under development.

An instruction consists of a one-character op-code, up to two operand addresses and an optional single character variant.

An item-marked op-code would be handled differently from normal, and this was used in the emulation of IBM 1401 instructions that were not directly compatible.

The object file began with a bootstrapping routine so that each program can be loaded into memory, from card reader or magnetic tape, using a boot command from the console.

Higher Series-200 computers (H1200, H1250, H2200 and H4200) were mainframes in their own right, capable of handling (with the Mod 2 operating system) up to two simultaneous job streams in addition to the "resident monitor" (i.e. the kernel).

System console, left, (shown with IBM 1402 card reader/punch ).
Closeup of system console. After a program was loaded, the value of individual memory locations can be altered using the console buttons.