Re:IRS’ 60-Year-Old IT System Failed on Tax Day Due to New H...
by js8 on Monday April 30, 2018 @02:42PM
(#16961119)
IBM mainframe assembler is actually somewhat abstracted from the hardware. The original assembler is very CISC-like, but today it's running on RISC-like cores.
As for the hardware, I/O is done through channel programs, which can have any device as a backend - it's a generic way to do DMA.
There is a lot of legacy stuff (like CCKD, VTAM) but more or less it's all emulated today by the hardware/software.
As for the hardware, I/O is done through channel programs, which can have any device as a backend - it's a generic way to do DMA.
There is a lot of legacy stuff (like CCKD, VTAM) but more or less it's all emulated today by the hardware/software.