On 25 December 2015 at 20:55, Mike Ross <[email protected]> wrote: > What do people reckon would be the best target for emulation? 3340 > springs to mind initially... would that work on machines as old as > System/360s? It's about the *only* option for 5415 DASD... > The 3340 is a pretty "small" disk at least for mainframe DASD.
More useful would be the 3330-1 and 3330-11. You can gen OS/360 21.8F and MVS 3.8J to 3330 (assuming of course you have a 370 of some sort knocking around). Unless I'm completely wrong, most of the various control units presented a programming interface that was relatively similar/the same amongst the various kinds of DASD (looking at the 2844/2314 and 3830/3330 for example). Naturally the best way to double check that would be to look at sufficient reference manuals, though if you felt less inclined you could try browsing the source of the Hercules emulator for how it does DASD emulation. Now for the topic of System/3 DASD; firstly the control "speaks" a completely different set of commands compared to the channel attached DASD of the "proper" mainframe world. The 5444 disk is it's own thing and not related to any of the channel attached DASD. The 5445 is basically a single 2314 unit; and the 3340/3344 are exactly what they say they are. Images of the 5445 and 334x drives would be interchangable with the 2314 and 334x (since the format the System/3 uses on those disks is compatible with mainframe systems). As a kind of dumb thought, for storing the images of the Count-Key-Data DASD perhaps abuse the Hercules CKD/CCKD code into the hardware emulator? (Means you can move your emulated disk packs to and from a Hercules instance if you had reason to do so.) Sorry for blathering on, I'm not an expert and I haven't a clue how easy or difficult it would be to implement any of these ideas. Cheers, Christian -- Christian M. Gauger-Cosgrove STCKON08DS0 Contact information available upon request.
