Model 204 system requirements

Operating system support

Model 204 Release V7.5

Release V7.5 is supported on the IBM z/OS, IBM z/VM, and IBM z/VSE operating system environments.

IBM z/OS

The latest z/OS version supported is V2.1.

V1.7 or later is required.

V1.7 is sufficient for all new functionality except for the following features:

• Large (1 MB) page support requires V1.9.
• Extended address volumes (EAV) requires V1.12.

Authorization under APF is required to run Model 204 V750 under any z/OS operating system.

IBM z/VM

The latest z/VM version supported is V6.3.

z/VM V5.4 or later is required.

IBM z/VSE

The latest z/VSE version supported is V5.2.

z/VSE V5.1 or later is required.

Model 204 Release V7R4

Release V7.4 is supported on the following operating system environments:

• IBM z/OS versions 1.09 through 2.1
• IBM z/VM versions 5.3 and 5.4
• IBM z/VSE version 4.2.1

Model 204 Release V7R1

Release V7.1 is supported on the following operating system environments:

• IBM z/OS versions 1.09 through 2.1
• IBM z/VM versions 5.3 and 5.4

IBM z/VSE is not supported.

z/OS 2.1 compatibility issues

In Model 204 versions 7.5 and lower, Horizon TCP applications sending data larger than 16K might get the following error:

M204.1254: User language statement is invalid in this conversation state

This error occurs under z/OS version 2.1 because the TCP Default Send Buffer Size (DefaultSndBufSize) was increased to 65536 (from 16384 in earlier versions).

Solution

• Model 204 v7.5:
  Apply zap 75Z226.
• Model 204 v7.4:
  Currently fixed by zap 74Z4552. Contact Model 204 support.
• Model 204 v7.1 (and lower):
  Workaround: Set z/OS 2.1 TCP DefaultSndBufSize to 16384.

Hardware requirements

Model 204 requires the IBM zSeries processors listed below for each Model 204 release.

Model 204 Release V7.5

Model 204 version 7.5 requires the IBM z/890 or above processor, except for the following feature:

• The large (1 MB) page support feature requires the IBM z10 or above processor.

Model 204 Release V7.4

Model 204 version 7.4 requires the IBM z/890 or above processor, except for the following feature:

• The large (1 MB) page support feature requires the IBM z10 or above processor.

Model 204 Release V7.1

Model 204 version 7.4 requires the IBM z/890 or above processor.