¿ªÔÆÌåÓýHarold, ? Its my experience that other things in VM required EC Mode because they also need like ¡°SET TIMER REAL¡± which needs ECMODE and changing modes needs an IPL¡. So for example many of the ¡°WAIT¡± commands need ECMODE¡.. ¡ so whilst running in BCMODE uses less resources, in many cases it creates problems so you set every one in EC MODE. If memory serves me correctly enabling ECMODE does NOT set the machine into ECMODE you need to load an ECMODE PSW¡.. ? Dave ? ? ? ? From: [email protected] <[email protected]> On Behalf Of Harold Grovesteen
Sent: 30 April 2022 15:11 To: [email protected] Subject: Re: [h390-vm] ECMODE on in every user directory entry ? I agree with the use of the I/O masks on S/360. ?However in BC-mode on S/370, bit 6 is architecturally available for enabling interrupts from higher channel numbers. ?GA22-7000-0, page 8. ?VM could have supported higher channel numbers in S/370 BC-mode. ?Whether any actual S/370 systems supported use of bit 6 in BC-mode could be a question. ?Clearly VM/370 does not implement use of bit 6 in BC-mode VM's. ?To the extent that VM virtual machines in BC mode were expected to support S/360 operating systems, it would make sense to only support PSW bits 0-5 for channel interruptions. ? Just a nit... ? Harold Grovesteen ? On Sat, 2022-04-30 at 08:24 -0500, Jay Maynard wrote:
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