Chuck(G)
25k Member
No I'm not. EBCDIC or ASCII representation is hard-coded into the S/360 and later machine microcode.
As a very simple example, consider S/360 packed decimal representation. In particular look at Pinciples of Operation, PDF page 35, second paragraph. In the following sections, note that in the case of ED, EDMK and UNPK instructions different codes are generated, depending on the setting of the PSW "A" bit.
As another example, consider the Unpack to Zoned instruction on the CDC STAR manual here. Starting on page 288, note the discussion about coding of signs and digits, depending on the ASCII or EBCDIC bit setting in the applicable instruction.
The coding has nothing to do with peripheral function---it's hard-coded into the CPU firmware. The user is not free to use his own representations and expect the hardware to function correctly.
As a very simple example, consider S/360 packed decimal representation. In particular look at Pinciples of Operation, PDF page 35, second paragraph. In the following sections, note that in the case of ED, EDMK and UNPK instructions different codes are generated, depending on the setting of the PSW "A" bit.
As another example, consider the Unpack to Zoned instruction on the CDC STAR manual here. Starting on page 288, note the discussion about coding of signs and digits, depending on the ASCII or EBCDIC bit setting in the applicable instruction.
The coding has nothing to do with peripheral function---it's hard-coded into the CPU firmware. The user is not free to use his own representations and expect the hardware to function correctly.